#OTLeipzig24 impressed with its range and quality of contributions

The ZVO women's network, which was founded in November 2023, introduced itself for the first time. Dr Elke Moosbach, Head of Female SurFaces on the Executive Board, began by outlining the origins, development, goals and projects of the network, which stands for increasing the proportion of women in electroplating and surface technology and counteracting the shortage of skilled workers by recruiting more female specialists. The relevance of these aspects was already evident when looking at the proportion of women at the ZVO Surface Days: in 2023, only 10 per cent of participants were female, compared to 15 per cent in 2024. An increase in which the Female SurFaces may already have played their part.

Afterwards, the pleasingly large number of female and male visitors to the session were treated to presentations by four role models from the ranks of the Female SurFaces: Hannah Betz, Sally Kulemann, Lisa Büker and Patricia Preikschat introduced themselves and their very different backgrounds and professional careers in surface technology.

This was followed by a keynote speech by Tanja Gebel, WHW Hillebrand, on the topic of mentoring in organisations - a powerful tool for personnel development that is becoming more important than ever. Countless success stories from companies and organisations that already use this tool confirm this. The surface industry in particular can benefit from the use of mentoring, supporting both men and especially women in the still male-dominated industry to develop successfully and efficiently.

In the general definition, mentoring is described as a "counselling and support process". Classically, this is a hierarchically independent relationship between an experienced person (mentor) and a less experienced person (mentee). The experienced person (mentor) shares their experience, knowledge and skills with the less experienced person (mentee) on the topics/goals that the mentee has in order to sustainably support and promote the mentee's personal and professional development.

Firstly, the mentee's goals are identified. A suitable "tandem partner" (mentor) can then be selected. A pool of mentors is helpful for this or the company can take part in an existing programme.

Once a suitable match has been found, the "tandem" gets to know each other and meetings are arranged.

A time frame is usually set for the tandem work, usually one year. During this "mentoring year", the mentor and mentee meet at regular intervals of around four to six weeks. The mentoring tandem organises the meetings independently. In particular, the mentee is responsible for the organisation (taking minutes, organising appointments).

Depending on requirements, suitable events (network meetings, training sessions, accompaniment to lectures, etc.) can be attended or identified during this time that promote the mentee's goal/topic.

The promotion of competences and skills varies and is differentiated depending on the mentee's goal/topic:

The target groups are diverse:

• During further development "from colleague to manager"
• New to the role of manager
• Managers who want to develop further or experience new perspectives/viewpoints/reflection (e.g. new demands on the role)
• Project managers or specialists
• During training/studies

The following mentoring options are available:

• One-to-one mentoring
  • Both work together as a mentoring tandem over a longer period of time, usually for a period of one year.
• Group mentoring
  • A group of mentees is supported by a mentor over a longer period of time.
• Peer mentoring
  • A group of peers organise themselves to realise a project and support each other.
• Cross-mentoring
  • A special form of external mentoring in which the mentee receives a mentor from another organisation/company.

The advantages:

• Promotion and motivation of professionally ambitious employees
• Sustainable personnel development and recruitment
• Prevention of a shortage of specialists and managers through the development and retention of qualified employees
• Positioning as an attractive employer through the use of innovative HR tools
• Securing expertise within the company
• Gaining new impulses and impressions from other organisations in order to question existing structures and processes in your own company
• Appreciation towards the mentee and mentor

Special advantages of "cross-mentoring":

• This often creates a faster relationship of trust between mentee/mentor, as there is no direct professional or hierarchical connection.
• The choice of mentors is greater, so there is a much higher chance of finding a suitable match.
• Small and medium-sized companies can also offer a mentoring programme in this way.
• Both mentee and mentor gain new impulses and impressions from a different corporate culture.

Katja Feige followed with a presentation on the topic of working (time) models. She began by presenting various possible models. She then summarised the results of the Female SurFaces survey, which ran from mid-July to the end of August with the aim of recording personal experiences, wishes and suggestions regarding working (time) models, home office options, childcare and the general promotion of women. The questionnaire was addressed on the one hand to women (29 responses) and on the other hand to companies (54 responses).

A comparison of the results revealed clear similarities: Flexible working time models are valued by female employees and companies and are widespread. However, there were also differences in the perception and implementation of certain aspects such as working from home, childcare and the advancement of women. A closer look at the critical points by the companies could help to overcome these discrepancies and better tailor the offer to the needs of the employees. Women, on the other hand, could benefit from more intensive communication about existing offers in order to eliminate uncertainties and promote the use of existing models.

The event concluded with an extremely well-attended, lively and stimulating panel discussion chaired by Judith Klups. Women and men expressed their views - sometimes controversially, but always openly and respectfully - on theses and key issues relating to working time models, the advancement of women, equal opportunities, women in management positions, work-life balance, the shortage of skilled labour, etc. The "vacant chair" on the podium did not remain unoccupied for long; it was occupied by alternating speakers and the audience also took a lively part in the dialogue.

The lecture programme also once again included a consultation hour from the ZVO's Environmental and Chemicals Policy department. As last year in Berlin, it was organised as a question and answer session: Experts from the department were available for information and discussion.

After introducing the department, head Dr Matthias Zimmer addressed a number of key topics that could be significant and more than challenging for the industry. These included the topic of chromium trioxide under REACH, the PFAS restriction draft and the current revision of the STM-BREF on the basis of the revised Industrial Emissions Directive 2.0. The latter now goes far beyond its name. Instead of just dealing with and regulating emissions, in future it will also require the specification of the quantities of authorised input substances (so-called BAT-AEPLs[1]), including water and energy. This requirement calls into question the free choice of products and production processes as well as further developments. Expert opinions that prove that a process cannot be operated with fewer input materials are intended to offer a way out of this encroachment on entrepreneurial freedom. This would not only increase the costs and time required for authorisations. Bureaucracy would also increase and planning uncertainty would grow. The only beneficiaries will be consultants, who will have to support companies in the preparation of documentation that is compliant with the authorities.

The topic of BREF dominated the consultation; for many, these massive regulations were largely new. The question arose as to how far regulation should go, given that the proportion of non-value-adding activities has already reached an unhealthy level - at least for SMEs. The question of how and with what wording to react was also raised.

It was regretted that only around 30 of the numerous participants at the Surface Days had found their way to this consultation. Discussions about possible reactions from outside the industry will therefore have to be continued.

The consultation ended with an invitation to actively participate in the department, which on the one hand serves to provide information and on the other hand strengthens the association.

[1] Best-avaliable-technologies-associated-environmental-performance-level

Christoph Kiesl from fem in Schwäbisch Gmünd focussed on the topic of "post-lithium batteries". If defossilisation is based unilaterally on electrification using lithium-ion technology, this is known to harbour strategic risks due to the limited availability of lithium minerals. Alternative approaches, such as calcium anodes, are gathering under the buzzword "post-lithium". In his work, Kiesl primarily focussed on the deposition of calcium from non-aqueous electrolytes for the production of anodes.

Dr Mathias Weiser, Fraunhofer IKTS, Dresden, reported on the results of the IGF project "Elektro-SnOx". The project focusses on porous tin oxide as an electrode material for highly efficient lithium-ion batteries. The manufacturing process consists of tin deposition from a commercially available tin electrolyte and anodic oxidation of the tin to produce the porous oxide.

The first session of the "Young Colleagues" was rounded off with another presentation from the field of "renewable energies", namely hydrogen technology. Dr Johannes Näther from Mittweida University of Applied Sciences showed that electrochemical expertise is required twice for the production of electrodes for acidic water splitting: firstly, for the question of which electrode materials are particularly suitable for efficient water splitting, and secondly, how precious metal catalyst particles (in this case IrRu) can be deposited in a particularly material-saving manner in order to produce the electrodes.

The first lecture of the second "Young Colleagues" session was presented by Lukas Esper from TU Ilmenau. It was generally about the electrochemical polishing of workpieces produced by laser sintering, which are known to have a high surface roughness. A medical implant (stent) made of 316L stainless steel served as a concrete example. This type of implant is also partially processed by electropolishing in conventional manufacturing processes in order to smooth the surface. The surface quality currently required cannot yet be achieved with laser-sintered parts.

Last year, Nurul Amania Binti Omar from Mittweida University of Applied Sciences presented an exciting method of producing NiPB coatings in which boron particles are first co-deposited in chemical NiP and then the ternary phase with promising properties is produced by heat treatment. In this year's paper, Omar dealt with the corrosion resistance of the unique alloy and ventured into the field of comparability of salt spray tests and electrochemical polarisation and impedance measurements. As expected, the results were controversially discussed.

Classic surface technology and renewable energies came together in the presentation by Lea Breu from Robert Bosch Manufacturing Solutions GmbH. Parameters such as current intensity and process time influence the structure of the oxide layer during the anodic oxidation of aluminium. Breu investigated how these parameters influence hydrogen permeation so that the aluminium components can be used in hydrogen technology applications.

Lukas Böttger from Chemnitz University of Technology then addressed the properties of anodised layers. His focus was on using porous oxide layers to improve the adhesion of PLA plastic in aluminium-plastic composite components. The PLA plastic is applied here using the melt application process. As expected, the parameters in this step have a major influence on the result. Böttger showed impressive scientific rigour in the planning of his experiments and the preparation and presentation of the results. The study was carried out as part of a project.

Influencing variables in the electrochemical deposition of various alloys have always been part of the wealth of knowledge and experience in electroplating technology. Scott Dombrowe from Mittweida University of Applied Sciences impressively demonstrated that there is still new territory to be discovered in this field of knowledge. He has carried out research and development work in the field of nickel-rhenium alloy deposition and has worked out some drastic influences of the deposition conditions on efficiency and alloy composition.

Stephan Daniel Schwöbel, who works in Prof. Lampke's research group at Chemnitz University of Technology, reported on progress in the modelling and simulation of electrochemical deposition processes. He initially chose the relatively simple model system of an additive-free (or "-poor") acidic copper deposition. Even here, hours of calculations on powerful computers are sometimes necessary as soon as the consideration is extended from the primary to the secondary current density. As a mathematician, Schwöbel can work at the level of optimisation algorithms and is not dependent on commercial programs, which will benefit future applications on more complex systems.

The contribution by Jonas Rehbein, TU Ilmenau, marked a return to classical electroplating technology with a concrete, practical application: the addition of sulphur in soluble nickel anodes leads to depolarisation and thus to more efficient and more uniform dissolution. If pure nickel anodes are used, this has a potential influence on the layer properties of deposited nickel layers, such as the internal voltage. A cutting-edge aspect is the influence of PFAS-free wetting agents on the layer properties compared to PFAS-containing wetting agents.

Suvetha Logeswaran from Aalen University has taken up the challenge of improving the understanding of particle co-deposition through an energetic approach. The model system chosen was a nickel matrix with SiO2 particles. In order to determine the SiO2(glass)/nickel interface energy, glass substrates were metallised using PVD and then subjected to a pull-off test ("PosiTest"). The subsequent discussion provided valuable information on how to overcome existing practical hurdles in this approach.

As Stephan Koß, RWTH Aachen, Digital Additive Production, emphasised, the use of Extreme High Speed Laser Application (EHLA) in particular is increasing in the industry due to the technological flexibility in terms of productivity, the almost free choice of materials, the high efficiency and the precise local material deposition.

This technology enables precise energy input into the coating material and then into the substrate, so that almost all coating materials (e.g. metal matrix composites) can be used and almost all material combinations (coating of aluminium with stainless steel, coating of fibre-reinforced polymers with aluminium) can be realised. In contrast to classic laser cladding, EHLA uses new laser technology to melt the powder before the particles hit the surface. This reduces the thermal load on the substrate material.

Typical layer thicknesses in one pass vary between 20 µm and 350 µm. The deposition efficiency is up to 95 per cent, depending on the process parameters and the coating material. Productivity can also be increased by changing the energy input. For example, an area performance of around 1,300 cm2/min can be achieved with a laser power of 8 kW. These properties make it possible to optimise surfaces to meet different requirements, for example to provide targeted protection against corrosion and wear, to adapt tribological contacts or to structure surfaces through additive material deposition. More recent developments deal with the coating of plastics, for example carbon fibre-reinforced polyamide, which can be coated with aluminium.

In his presentation, Dr Roy Morgenstern, TU Chemnitz, Chair of Materials and Surface Technology, dealt with the process of anodising with a coaxial electrolyte jet using sulphuric acid in order to produce surfaces for tribological applications with a high layer formation rate.

The special process of anodic oxidation with an electrolyte jet is suitable for the energy- and resource-efficient, localised and coverage-free surface functionalisation of aluminium alloys. The coating of the electrolyte jet with deionised water in a coaxial arrangement enables both a stronger localisation of the layer formation and the safe use of comparatively aggressive, sulphuric acid electrolytes, which are characterised by high layer formation rates at relatively low process voltages, due to the dilution of the outflowing acid.

Using the coaxial arrangement, compact oxide areas with self-organised pore growth and thicknesses of more than 50 µm could be produced. The formation of the layers was localised within a diameter of a few millimetres. The process stress and consequently the layer formation rate are limited by forms of burning in the centre of the anodised surface.

Component cleanliness is generally understood to mean compliance with limit values regarding contamination with undesirable substances on the surface. According to Dr Björn Dingwerth, MacDermid Enthone GmbH, particles of certain size classes and corresponding limit values, specified as the number of particles in a representative surface segment, are generally considered here.

The relevance of component cleanliness came into focus with the advent of diesel direct injection systems in the late 1990s and early 2000s, as particles entering the delicate injection nozzles became a problem. This challenge was successfully met with appropriate limit values and measures to maintain cleanliness and tolerable levels of contamination.

The current paradigm shift in mobility from combustion engines to electric drives has an impact on connecting elements in general and in particular on the technical cleanliness of these elements. As the proportion of electric drives continues to increase, experience in their use is growing and the relevance of component cleanliness for the reliability of the underlying system components is once again becoming apparent.

The layers of cobalt-iron and iron-nickel presented by Dr Adriana Ispas, TU Ilmenau, are attracting great interest due to their magnetic properties. Such layers are used, among other things, as a base material for electronic data storage devices. In the future, they could also be used for electrical engineering in electric vehicles or in generators to produce electricity.

A special feature of cobalt deposition is that electrolytes with pH values below pH 5 form fcc crystals and hcp crystals at pH values above 5. This in turn also has an influence on their magnetic properties. Equally strong magnetic differences result from the composition of alloys, such as iron-nickel-cobalt. Furthermore, additives such as saccharin or citrate in the electrolyte influence the grain size of the deposit, among other things, as a result of which changes in the magnetic properties are to be expected.

Deposited cobalt-iron layers were thermally treated at temperatures of up to 800 °C. It was found that a change in the properties occurs at around 500 °C. This is due to an increase in the crystalline order, which in turn changes the magnetic properties. In addition, the grain size of the layers is significantly altered by the additive used, as are the magnetic properties. The same investigations were carried out on iron-nickel layers. Here too, the morphology showed differences due to the additives used. Using the electrochemical quartz microbalance, the current yield of the coating deposition could be determined in-situ. The cathodic current yield for deposits from these electrolytes is generally over 90 per cent.

In addition to galvanic chrome plating, which has undergone a significant change due to the restriction on the use of hexavalent chromium compounds, dispersion layers with PTFE particles are now also under pressure to change. The reason for this is the reduction in the use of PFAS substances, which include PTFE, and the PFAS surfactants required for dispersion. Alfadil Mohammedbrhan, riag Oberflächentechnik AG, deals with this topic. To his knowledge, there are currently no suitable alternatives known for PTFE; only PFAS surfactants can be substituted.

Electroless deposited nickel dispersion layers with embedded PTFE are characterised by a low coefficient of friction (CoF) and good non-stick properties; the proven uniform layer thickness distribution of electroless nickel layers is retained. Surfactants that must be compatible with the PTFE powder used are required for the production and stabilisation of the dispersion on the one hand and for co-deposition during nickel plating on the other. Fluorosurfactants ideally fulfil these properties, but according to the speaker, they should be banned as part of the PFAS restriction proposal ECHA/NR/23/01, or at least their use should be regulated. A system in which PTFE is used with PFAS without the use of a surfactant could be considered as a possible alternative to the systems used to date for the deposition of nickel-PTFE. A particular advantage is that a higher proportion of PTFE (up to 30 per cent) can be incorporated. In addition to the higher installation rate of PTFE, the layers from the new electrolyte systems have a lower roughness.

In practice, different pH values result in changes in the installation rate. The deposition rate decreases with decreasing pH value and decreasing electrolyte temperature. The sliding properties are largely dependent on the PTFE content in the coating, whereby a maximum installation value must be observed. The mechanical strength of the coating decreases at contents of well over 30 per cent. The non-stick properties, expressed by the contact angle, show a slight increase as the PTFE content of the coating increases.

Small, cost-effective, flexible and easy-to-handle sensor fuel cells are required for the further development of fuel cell technology. Additive manufacturing processes in combination with electroplating technology are suitable for the development and production of the metallic active surfaces. In her presentation, Miriam Dürr, fem Research Institute for Precious Metals and Metal Chemistry, described the production of sensor fuel cells, which are intended both to facilitate development and to test the quality of existing fuel cells. These sensor fuel cells must be flexible and cost-effective to manufacture.

Additive manufacturing guarantees the necessary flexibility at low cost. After the basic body is produced, for example from the plastic PA12, the production steps include mechanical surface treatment (smoothing) and galvanic metallisation. The plastic PA12 has good chemical and thermal resistance. Mechanical smoothing is most easily achieved by barrel finishing with glass beads and chemical smoothing.

For the coating of the cell, a multi-stage process consisting of ALD, electron beam evaporation and galvanic metal deposition has been used in previous work. Partial coating is realised by applying a masking layer. The galvanic layer must consist of a corrosion-resistant metal, whereby both chemical and galvanic deposition are suitable for this.

Good results have been achieved by combining chemical and galvanic deposition on a chemically smoothed surface. Chemical coating ensures complete coverage even of complex geometries; however, due to the low deposition speed, only coating thicknesses of a few micrometres (or less than 1 µm) are practical.

Hans-Joachim Kraft, MacDermid Enthone, presented a new process for the chemical deposition of nickel-phosphorus-tin. The layers produced with this process have a high corrosion resistance combined with a robust process and a lower metal content in the electrolyte. This allows the costs of the process to be reduced. Nickel layers with a high phosphorus content (over 10.5 per cent) have a significantly higher corrosion resistance than those with a lower phosphorus content.

In addition to the ternary substance in the nickel-tin-phosphorus alloy, a new type of additive system plays an important role in the resistance of the coatings. The deposition rate initially reaches values of around 18 µm/h and drops to around 10 µm/h as the service life increases (4 MTO). The advantage is that the internal stresses remain within the range of compressive stresses throughout the entire service life and change only slightly. According to the lecturer, compressive stresses increase adhesion to the substrate. The tin content of the alloy is just under 2 per cent and requires no additional additives in the electrolyte. The hardness of the layer in the deposition state is 450 HV100 to 500 HV100. This can be increased to values of up to 900 HV100 by tempering at 400 °C.

Corrosion resistance is generally tested using a nitric acid test. New electrolytes yield more than 4 minutes in the test and the values drop to more than 2 minutes at 4 MTO; pore-free coatings are also achieved at thicknesses of well below 12.5 µm. The new system for depositing nickel-tin-phosphorus makes the coatings more cost-effective, as the required properties (corrosion, wear) are achieved with a significantly lower coating thickness.

The development of new, environmentally friendly electrolytes, particularly in precious metal deposition, is the subject of research in electroplating technology. One topic that Dr Christoph Baumer, TU Ilmenau, is working on is the development of a cyanide-free electrolyte for the deposition of thick silver layers.

Thick silver layers of more than 20 µm and up to 250 µm cannot be produced using commercially available processes without cyanide, but are of great interest in electrical engineering. The use of new types of complexing agents requires a completely new formulation of the electrolyte. Additives, conducting salts and buffers must be redesigned. Classical methods were used to analyse the deposition mechanism and the mode of action of the additives.

It was found that cyanide-free electrolytes result in rough layers or reduced adhesion to nickel. In principle, cyanide-free electrolytes can be operated at a low pH value (below 2) or in the alkaline range (pH 9 to 12). In these systems, there are high differences in the Nernst potential, which must be equalised in order to achieve adhesive coatings; in other words, the silver ions must be complexed. Several possible complexing agents such as thiols, amines, phosphonic acids, imides, amino acids or carboxylic acids were investigated for this purpose. Good results can be expected with dimethylhydantoin (pH 10), for example. The macro-scattering ability is roughly comparable in alkaline and acidic systems, but worse than in cyanide processes.

It was also investigated which lustre additives would be suitable for cyanide-free systems, such as butenediol or cysteine, which should be able to influence the micro-scattering ability. The results with regard to microspreading capability have not been satisfactory to date, with four additives to electrolytes being investigated. One of the disadvantages of the electrolytes tested is the reduced adhesive strength. Combined use of alkaline and acidic systems might be promising.

Sustainability issues are playing an increasingly important role in a wide range of industries, be it in the use of certain chemicals or energy and resources. Dr Michael Schem, MacDermid Enthone Industrial Solutions, highlighted various aspects of sustainable business requirements in relation to sealants and topcoats, focusing on new markets.

Cost savings and stain-free drying are an ongoing topic in surface technology. In his presentation, Norbert Fessler, safedry, addressed the physical principles of drying in addition to the technical and economic aspects of drying. Important parameters for drying speed are temperature, humidity, air pressure and air speed. Other parameters of efficient drying relate to the energy flow of a drying system (material heating, convection, water evaporation, heat losses of the dryer). From this, he derived the framework conditions for a drying system, which include the utilisation of waste heat from the fans, the type of heating, insulation of the dryer, droplet separators, air dehumidification or equipment with cover systems. By listing the costs incurred for drying, starting with the necessary manual work through to the operating costs, the speaker showed the possibilities for minimising costs.

Reinhold Specht, Harter GmbH, also addressed the topic of drying in surface technology. According to him, drying is often the bottleneck in production, as conventional hot-air dryers often fail to achieve the desired drying quality within specified cycle times. And it is not uncommon for the dryer to consume a lot of energy. It is therefore worth taking a look at an alternative drying process that has been classified as an eligible technology: heat pump-based condensation drying, which, according to Specht, can save up to 85 per cent of energy and carbon dioxide emissions.

This type of drying differs from conventional methods due to its alternative physical approach. By dehumidifying with extremely dry air in an energetically closed system and targeted air flow, products are dried quickly, safely and in an energy-saving manner. Drying takes place in a variable temperature range of 40 °C to 75 °C, depending on the component and process. The process can be used flexibly - for batch operation or continuous applications. In addition to batch drying using rack dryers, bulk materials can also be dried directly in the container. It is also possible to dry industrial sludge from waste water treatment.

If the pickling solution used for the fine pickling of printed circuit boards contains more than 20 g/l copper, the pickling solution loses its effectiveness and must be replaced with a fresh one. The used pickling solution is sent for waste water treatment. In his presentation, Dr Jens Krümberg, Eilenburger Elektrolyse- und Umwelttechnik GmbH, presented a technology with which the copper contained in the pickling solution is removed from the solution as a metal and thus recovered. At the same time, the sodium peroxodisulphate reduced to sodium sulphate (Na2SO4) is reoxidised to sodium peroxodisulphate by means of an electrochemical process using diamond-coated anodes. The process can also be used for pickling solutions based on triple salt. The economic and environmentally friendly effect is that the pickling solution is recycled and up to 90 per cent of the sodium peroxodisulphate or triple salt can be saved. In addition, reusable metallic copper is produced in the form of copper anodes.

In his presentation, Dr Eckart Giebler, Collini GmbH, dealt with concentration control and material losses in deposition processes with a recirculation rinse (also known as an economy rinse), i.e. the first rinse after an electroplating process. Recirculation feeds valuable substances back into the process and prevents them from being carried over into the subsequent rinsing system. As Dr Giebler emphasised, metal savings through recirculation are very limited in many cases.

A mathematical model of the separation process and recirculation sink is used to analyse the material ratios in the recirculation process. This shows that the metal concentration occurring in the process depends on the carryover and recirculation. If complete recirculation takes place in accordance with natural evaporation, a natural metal concentration is achieved at a steady state. If this concentration is higher than the target concentration, this means an undesirable increase in the metal concentration. This increase can be counteracted by discarding it from the process or from the recirculation sink. It follows that throttling the recirculation can be an elegant alternative and therefore a simple control variable for reducing the metal concentration.

However, the minimisation of metal losses must be considered independently of the control of the metal concentration. Depending on how the target concentration is set, a recirculation process can operate in surplus or deficit mode. In the frequently occurring excess operation, the accumulating metal can be removed from the process by discarding it or from the recirculation sink and by throttling the recirculation. In all three cases, however, the metal is lost to the process and must be removed by wastewater treatment. The only way to minimise metal losses is to reduce the difference between anodic and cathodic current yield.

For a long time, electrocatalytic electrodes did not play a significant role in electroplating technology, as emphasised in the presentation by Christian Kurrle, Umicore Galvanotechnik, and Marvin Wagner, BIA. It was only with the application of decorative chrome plating using electrolytes based on chromium(III) compounds that the need for anodes with shielding became necessary in order to protect the organic material in the electrolyte, which is essential for the formation of lustre during deposition, for example. Uncoated cut edges of the anode and uncoated current leads were identified as the cause of the effect. Prefabricated anodes with no free titanium in the electrolyte were recognised as a solution. A further step was to improve the service life of the anodes by applying a thicker topcoat. However, this led to higher resistance and drastically shortened the service life.

Together with partners and manufacturers of electrolytes, anodes and processes were optimised. One of the challenges is the rising price of iridium, which is required for anode coating. According to the speakers, anode designs are now available that fulfil the requirements of coating companies in all respects.

Tomislav Maric, MKS Atotech, opened the series of lectures focussing on corrosion protection with a presentation on the challenges and effects of the ban on PFAS for zinc flake coatings on the entire supply chain. Perfluorinated chemicals are characterised by their high resistance, but this also means that they do not degrade in nature and therefore accumulate in living organisms. The artificially produced compounds are widely used as ingredients in non-stick agents, cleaning agents, clothing, extinguishing agents and sealants. In order to prevent continuous contamination in nature, the European Chemicals Agency ECHA presented a proposal for a restriction of PFAS at the beginning of 2023.

PFAS (in the form of PTFE) acts as a lubricant in zinc flake coatings, as its high thermal stability means that the lubrication values can be kept constant within a wide temperature window (baking temperature). As an alternative, coatings without PFAS have been developed which have the required properties for various applications. The new systems are currently in the introductory phase. However, according to the speaker's experience, the coatings come into contact with contaminated substances that are absorbed into the coating, such as contaminated water or equipment and previous processing, so that PFAS may still be present from case to case.

Aluminium alloys are characterised by good corrosion resistance and thus allow the protection of other metals, whereby the property of cathodic corrosion protection is of particular interest for steels. In order to enable coating, the use of aprotic systems is required, which Andreas Waibel from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA is working on. In his presentation, he introduced an electrolyte system for the deposition of aluminium-zinc. Aluminium-zinc is of particular interest as a replacement for cadmium coatings in the aerospace industry.

In contrast to pure aluminium, aluminium-zinc has the advantage that the alloy does not have a strongly inhibiting passive layer. Deposition from aprotic solutions must be carried out under inert gas, as the solvents are sensitive to air and moisture. Alternatives are ionic liquids, but these are very cost-intensive to produce. Strongly eutectic solvents are easier to produce. Waibel used toluene with aluminium chloride, lithium chloride and zinc chloride for deposition. This allows deposition current densities of up to 2 A/dm2 to be achieved. The available parameters such as hydrodynamics, complexing agents, anodes and organic additives were optimised for the system in order to achieve uniform depositions. The type of anode used has a strong influence; separate aluminium and zinc anodes as well as aluminium-zinc alloys can be considered, whereby an alloy anode is easier to handle. However, the strongly fluctuating zinc content in the electrolyte is a disadvantage.

Layers with zinc contents of between 10 and 15 per cent are deposited. Smaller fluctuations in the composition are achieved with single anodes, although the process costs are higher here. The deposition speed is around 0.2 µm per minute. The hardness of the layer is around 100 HV. At contents of 1 to 30 per cent zinc, compact and closed layers are produced. At a content of 4 percent zinc and more, the coatings show good behaviour as cathodic corrosion protection, comparable to cadmium. However, the inherent corrosion behaviour of the coatings still needs to be improved.

Zinc-nickel coatings in combination with high-performance passivation are often used to meet the demanding standards of the automotive industry. Although this combination offers advantages such as high current yield and fast coating speed, according to Katrin Krüger, Atotech Germany, the early appearance of an optical defect in the salt spray test, known as white haze, is disturbing. This appears very shortly after contact with moist air and remains unchanged for a long time until white rust sets in as cathodic corrosion protection. It clearly detracts from the decorative appearance of the parts.

The greatest challenge in clarifying the phenomenon is to examine the very thin layer of just a few nanometres. A statistical approach was used, supported by planning and data analysis with JMP software. Investigation methods such as SEM/EDX, Raman spectroscopy, XRD or XPS with depth profiling provided important information about the chemical composition of the layer and the corrosion products. The investigations show the difference between white haze and white rust, the main factors that influence the formation of white haze and allow conclusions to be drawn about the mechanism of white haze formation.

It is not uncommon for surface defects to occur during the production of components or strip goods, whereby even minimal defects can impair the function of a product or lead to problems during further processing. The Fraunhofer Institute for Physical Measurement Techniques IPM has developed an optical measurement system, presented by Andreas Hofmann, with which the quality of component surfaces can be tested in the production cycle.

This is a free-fall system with which a largely type-independent inspection of components up to a size of 200 millimetres can be carried out without additional handling. The component is inspected simultaneously by many cameras in free fall through the inspection sphere. Larger components are also captured by several cameras in an inspection tunnel. Geometric deviations, surface defects, coatings or soiling can thus be recognised. Almost all components can be recognised with this system due to their individual surface structure. The system is being trained for use in practice using CAD data of the parts.

The use of artificial intelligence (AI) is being tested in further development work. This should make it possible to recognise anomalies in complex parts. The scope of inspection could then be extended to include tasks such as sorting/identification, checking surfaces, dimensional accuracy, purity and coating data.

X-ray sources in ED-XRF measuring devices are often equipped with tungsten (W) as the anode material, as tungsten has both excellent long-term chemical and thermal stability and, due to its high atomic number, provides a very intense and universally applicable excitation spectrum, which proves to be advantageous for many applications in coating thickness measurement and analysis. However, according to Dr Cay-Uwe Pinnow, Helmut Fischer GmbH, there are limitations in individual applications due to the characteristic lines of tungsten, meaning that better alternatives are helpful for special applications. These anode materials include elements such as molybdenum, chromium or rhodium. In his presentation, the lecturer discussed the influence of the anode material as well as the advantages and disadvantages using application examples from industrial practice. This involved high-precision determination of the phosphorus content in chemically deposited nickel.

Critical chemical parameters in electrolyte solutions are traditionally determined using wet chemical methods. In the experience of Daniel Schlak, Deutsche Metrohm, titration or photometry are established methods that are used in robust process analysis systems for the efficient control of electroplating electrolytes. One way of countering the ongoing cost pressure due to rising labour costs is to use intelligent measurement and control technology for precise electrolyte monitoring. Approaches for high process efficiency and optimisation lie in the automation of established analysis methods and the use of chemical-free techniques using modern process analysers.

According to the speaker, process analysers that combine the accuracy of precise laboratory systems with robust modules for sample handling and user-friendly control software for communication with all common control systems are recommended. In addition to wet chemistry, ion chromatography and spectroscopy, X-ray fluorescence offers an interesting option for comprehensive analysis equipment. Using a practical example, the speaker presented the use of a fully automated solution for monitoring critical parameters using X-ray fluorescence in an electroplated zinc-nickel system. The advantages of the analysis system include a very short analysis time, extremely simple system operation, the elimination of reagents for the analysis and a high degree of flexibility in the design of the analysis module.

Jörg Friedrich, Car Men GmbH, shows in detail the changes that will result from new design concepts for previously metallised surfaces in vehicles. Over the next few years, these developments will primarily affect the parts inside the vehicle, as metallised parts have only been used to a limited extent on the outside for several years now. Developments in the key regions (Europe, America, China/Asia) are taking place at different speeds. What they all have in common is a strong trend towards the reduction of metal surfaces on plastic parts in favour of glass, which offers more options for designing the appearance while at the same time being highly robust in use. Furthermore, great importance is attached to a high level of environmental friendliness and sustainability in the use of plastics and metals. This means that recycled materials will be used to a large extent in the future. In this context, parts manufacturers are expected to take back parts for refurbishment at the end of their service life.

Current and future environmental regulations have a significant impact on users of plastic coatings (POP) and decorative coatings (DECO). The expected regulations will lead to further restrictions on coating chemistry, according to Dr Andreas Königshofen, MacDermid Enthone. This will bring new challenges for the development of processes that meet the stringent performance standards of OEMs while fulfilling legal requirements for employee safety and environmental protection.

To ensure compliance with these upcoming regulations, the development of critical technologies for plastic substrates without chromium(VI) compounds will be significantly intensified, with work focussing on chromium(VI)-free pickling and decorative chrome plating from trivalent systems. OEMs have been offered some technical options as alternatives to decorative finishes from hexavalent chromium processes. The emergence of decorative trivalent chromium systems with chromium(VI)-free post-treatment is already widely accepted. The colour versatility of surfaces made from trivalent chrome systems in combination with satin finishes has been recognised by designers as an advantage due to the high degree of creative freedom.

Based on performance in critical tests such as CASS, NSS and colour stability, the completely chrome(VI)-free decor system is the preferred replacement. Recently, automotive manufacturers have started to mandate chrome(VI)-free decoration processes for the production of vehicle parts. New, innovative measurement methods facilitate and enable the application, for example through the short test time in the CASS test. The use of chromium(VI)-free passivation also shows similarly good passivating properties as systems containing chromium(VI).

The pickling of plastic surfaces for electroplating is known to create the prerequisites for further process steps such as activation, acceleration and metal deposition, as Dr Sarah Schmitz, Delta Engineering & Chemistry, emphasised in her introduction. In order to create alternatives to the previously used pickling with chromium (VI) compounds, she focussed on the development of a method using dissolved ozone. This would provide a further alternative to chromium sulphuric acid alongside permanganate and sulphur trioxide.

The major advantage of using ozone is the fact that it is generated from oxygen and decomposes into oxygen again. Generators for producing ozone from gaseous oxygen are already used in the semiconductor industry. When ozone is used, there is also no waste water to be treated. For the pickling process, ozone is injected under pressure into water, which in turn acts as a pickling medium for the ABS plastic. The technology is very easy to integrate into existing systems and also requires no extraction or decontamination. The time that ozone remains in the medium can be adjusted to between a few seconds and a few hours.

The process is currently being tested in a pilot plant in Solingen. At concentrations of 20 ppm to 80 ppm, the pickling time is between around 10 minutes and around 20 minutes at ozone solution temperatures of 25 °C to 50 °C. The pickling pattern largely corresponds to that achieved by treatment with chromium-sulphuric acid. In addition, the new process does not require the swelling agent used with permanganate. The adhesive strength of the applied metal layers fulfils the specifications. Another advantage of this process is its high selectivity for components made from the plastics normally used.

Dr Sven Neudeck, SurTec International, presented a process for decorative coating that is completely free of chromium(VI) compounds from pre-treatment to the final layer and therefore fulfils all regulatory requirements. The focus is on a manganese-based plastic pre-treatment with a novel, palladium-free catalyst system, which significantly simplifies and shortens the process sequence. The performance and limits of the new process were tested in initial series runs. The results show no problems with the rack metallisation and demonstrate a high selectivity on 2K components.

In his presentation, Dr Jürgen Hofinger, Biconex, introduced a new plastic pre-treatment process for metallisation that works without the usual pickling treatment and offers greater stability, environmental protection and cost savings. The process is a joint endeavour between Biconex and the Leibniz Institute of Polymer Research Dresden. This work is particularly promising because the potential for the proven chemical galvanic coating of plastics is high due to the current heightened awareness of energy and resource efficiency as well as sustainability. After all, even the recycling of coated plastics and the reuse of metals and plastics in high-quality products for applications in the automotive and sanitary industries have been successfully demonstrated in recent years.

The fact that the chemical galvanic coating of plastics is still not common, especially in the field of technical components, is due, among other things, to the strong dependencies of the sub-processes from the selection of the plastics through injection moulding to the galvanic process, a high quality risk, costly upscaling of the processes and the existence of conventional systems for coating. However, the great potential is not only achievable through small incremental improvements, with pickling being a particularly worthwhile target, according to the speaker.

A new process, which is slowly becoming ready for series production, shifts this process step to the injection moulding machine. Here, a particle-containing modifier is sprayed into the injection mould before the injection process. The particles then enter the surface of the plastic mould and are subsequently dissolved out with hydrochloric acid to create the required porous surface. This technology is also suitable for partial metallisation and is therefore well suited to the production of very different and complex metal-plastic combinations.

Bernd Frank, Atotech Germany, focused on promoting sustainability, improving environmental performance and resource efficiency as well as ambitious framework conditions for surface plating. On the one hand, he sees a sustainable coating for the automotive industry, free of chromium(VI) and PFAS with durability and high quality, as key aspects. On the other hand, in his opinion, a study on the CO2 footprint of electroplating provides a very positive picture by analysing material and energy consumption for optimisation, including a comparison with alternative technologies. From this, conclusions can be drawn with regard to a production-proven chrome-free pre-treatment of plastics, the guarantee of sustainable, decorative coating alternatives without hexavalent chromium and without PFAS, as well as a positive life cycle assessment of decorative electroplating compared to alternative, chrome-like technologies. It should therefore become clear that decorative electroplating can make a valuable contribution to reducing the CO2 footprint in the automotive industry.

State-of-the-art control and automation technologies are often associated with the construction of new, highly complex systems. However, as Andreas Scholz and Florian Wimmenauer, Aucos AG, made clear in their presentation, it is often possible to avoid expensive new builds by upgrading existing systems to modern technologies to increase their performance.

The various types of systems found in practice, from manually operated to semi-automated to fully automated, present different challenges in terms of system control. Accordingly, there are also different ways of using modern technology to simplify the electroplating production process and increase the output of a system. For example, processes allow all process sequences to be stored centrally in the system control and each individual process step to be logged in a manually operated system. With another variant, an order backlog can be optimised on the basis of available personnel, available production resources and available plant capacity. It is becoming increasingly interesting that a system can be optimised independently in terms of energy consumption with the help of an intelligent control system and that equipment can be made available or deactivated independently.

Using the potential transient method, an electrochemical sensor system for real-time monitoring of the degreasing, pickling and passivation process steps within a deposition line for zinc-nickel coatings on steel parts was developed and its industrial applicability evaluated. The sensor system presented by Prof. Dr. Guenter Schmitt from IFINKOR - Institut für Instandhaltung und Korrosionsschutztechnik gGmbH, is characterised by the fact that the component to be treated is immersed as an electrode in the respective process medium under its usual operating conditions and the time course of the electrochemical potential of the component surface is measured against a reference electrode right from the start.

The respective process step is completed when the slope of the potential-time curve assumes a value close to zero (dU/dt 0) and a potential plateau is reached. The time in which the criterion (dU/dt 0) is reached can be used to control the cycle time of the respective process step, to evaluate the effectiveness of the medium and, in the case of the degreasing and pickling process steps, to evaluate the intensity of contamination of the component surface by grease or metallic cover layers. When the criterion (dU/dt 0) is reached, optimum hydrophilicity of the metal surface is achieved in the alkaline degreasing medium. In the pickling solution, optimum surface activation is achieved with this criterion, which is confirmed by determining the adhesive strength of the zinc-nickel layer. Optimum corrosion protection is achieved in the passivation based on chromium(III) compounds and zirconium. The industrial applicability of the monitoring method was demonstrated using the example of zinc-nickel passivation.

According to Sebastian Breuckmann, Ditec Dr. S. Kahlich & D. Langer GmbH, while process times and temperatures in electroplating practice are fully automated and often precisely adhered to, there are often significant fluctuations in the composition of process media, which can be reflected in quality and resource costs. Proper electrolyte maintenance usually requires highly qualified personnel and expensive technical equipment.

Taking into account the diverse influences on electrolytes, currently used methods and a new solution approach are being considered that simplifies and automates electrolyte management by utilising data without major hardware modifications. The focus here is on achieving added value for the user. A corresponding digital electrolyte management system can also be used, for example, to introduce new, more complex processes and research coating materials. The use of the developed digital electrolyte management results in optimisation potential and solution approaches to save costs, achieve quality improvements or achieve sustainable process expertise.

Progressive digitalisation, which Dr Peter Schwanzer from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA is looking into, is opening up new opportunities for electroplating technology, but also presenting companies with new challenges. There are different requirements and solutions for different areas of the company, but according to Schwanzer, there are numerous opportunities to increase efficiency and quality.

Data and data availability form the basis of digitalised electroplating technology, but added value can only be achieved through its targeted use, for example through specific data analyses or, increasingly in the future, through machine learning and artificial intelligence. As part of the SmARtPlaS project funded by the German Federal Ministry of Education and Research (BMBF), Fraunhofer IPA has set up a learning electroplating centre for the development and pilot application of Industry 4.0 approaches in electroplating technology. Based on previous work focusing on production technology, approaches for the digitalisation of electroplating technology were developed for more efficient plant operation. The application of machine learning in electroplating was tackled with the help of learning electroplating for data generation. Schwanzer presented the first positive results as well as the challenges encountered during his presentation.

Electroplating processes offer enormous potential for saving energy and resources. The recording of all relevant process parameters is essential for this. However, suitable and sufficiently cost-effective measurement technology for the production environment is not yet available. Rowena Duckstein, Fraunhofer Institute for Surface Engineering and Thin Films IST, and Marija Rosic TU Braunschweig/Institute for Machine Tools and Production Engineering, presented the current results of the BMBF-funded KI-InGatec project.

The project pursues the approach of developing an AI-based metrological system solution for industrial electroplating technology that can be used to provide a large number of the process parameters relevant for the digitalisation of electroplating production processes cost-effectively and with sufficient accuracy. The key point is therefore the replacement of a large part of the otherwise necessary, expensive chemical analysis with AI-based data evaluation. The planned system solution should be fully integrable as a cyber-physical production system and have the necessary interfaces.

As Arnaud Kropp, Softec GmbH, emphasised in his introduction, contract finishers are faced with a variety of options for optimising their operations in the context of digitalisation. The specific options that come into question vary from company to company, as digitalisation offers a wide range of solutions. For example, companies in the subcontracting sector can get started with digitalisation by exchanging data between offices and production. The feedback of operating data can be achieved in several ways: via fixed terminals, via app, RFID or system coupling.

Digital applications can be used, for example, for production data acquisition, checking technical parameters, loading and stock lists, component recording and tracking with the support of photos through to AR apps that support the work of employees with a wide range of background data. This is made possible, among other things, by the extensive linking of devices and applications with suitable interfaces available today. The technical realisation and the potential for further development of augmented reality technology will be demonstrated using a learning electroplating system at Fraunhofer IPA.

Even though many internal company processes in the areas of accounting, ordering, customer and quality management have already been digitalised, there is still a need to link, evaluate and prioritise data in the most advantageous way possible. In his presentation, Fabian Herbst from BAG Analytics GmbH used the example of warehouse and hazardous materials management at a surface treatment company to show how centralised data management that links all areas can be used to significantly improve and accelerate operational processes while simultaneously reducing risks.

A system he helped develop monitors chemical stocks, for example with regard to minimum and maximum stocks, but also with regard to the resulting capital commitment. In addition to the hazardous substance class, the environmental index of the respective chemical is also recorded and evaluated. The decisive advantage of data linking is the agile retrieval of data and the speed of action in an emergency.

In the aviation industry, as in other industrial sectors, new products based on Cr(III)/Zr(IV) are being developed to replace chromium(VI)-containing conversion coatings on aluminium. According to Tabea Eigenthaler, Airbus Defence and Space GmbH, the challenge of this coating is detection due to the low coating thickness (around 100 nm) and the bluish iridescent colouring, which makes the frequently used visual inspection more difficult.

In a study, a detection method was developed to meet this challenge. A test concept was created using established measurement procedures and new methods based on various aspects. If possible, a portable and non-destructive technique should be established that is suitable for applications in repair and production. A specially developed colour probe, X-ray fluorescence analysis (XRF) and the hyper-spectral imaging (HSI) method are advantageous for detection.

Daniel Zirngast and Bjarne Zimmer, Virtual Visions oG, have set themselves the goal of improving familiarisation with new processes or the operation of machines and generally increasing the attractiveness of professions through the intensive and innovative use of digital equipment. They want to create learning and experience processes without the pressure of real production, for example through possible damage to materials and people.

They utilise the fact that almost all conceivable environments - real or virtual - are generated in computers and can be displayed for a user using VR glasses. Manual activities can be made tangible with appropriate handheld devices. Corresponding technologies can be used for training, hazard simulation, maintenance and repair as well as for marketing and sales in the form of virtual showrooms. The notable advantages of the technology include cost reduction, avoidance of language barriers and the use of a safe environment, i.e. the avoidance of accidents at work, or the optimisation of processes.

Challenges currently still exist in managing the effort required for large process environments and complex system technologies. One example of a project customised by the lecturers is training on a CNC machine or expanding the use of a CNC machine. Real training courses that take several weeks can be reduced to just a few hours by working in the virtual version. In the future, progress will be made through enhanced networking, mixed reality and augmented reality, ultimately leading to a more pleasant working environment and increased production efficiency. In a complex field such as surface technology, this technology will not only increase efficiency, but also the much-needed attractiveness of the profession.

As Ornella Tchimkap, Umicore Galvanotechnik GmbH, emphasised in her introduction, connectors in particular play a central role in electromobility for the transmission of high electrical power, for example for electric vehicle (EV) charging. An important technical and scientific question is how charging processes can be made safer, faster and more sustainable. As silver has the highest electrical conductivity of all metals and good thermal conductivity at a reasonable cost, the metal is increasingly being used for contact coatings in electromobility. However, due to its limited self-lubricating properties and poor wear behaviour, pure silver is only used to a limited extent for high-performance contacts.

New developments, such as electrochemically deposited dispersion layers of hard silver and graphite, offer themselves as a further development of connectors for EV charging. A particular focus is on researching new surfaces with the lowest possible ageing, which would be possible with hard silver layers with good abrasion resistance. As Tchimkap explained, electrolytes have been developed for the deposition of dispersion layers with higher hardness and better abrasion resistance. Good results were achieved with cyanide-containing hard silver electrolytes with embedded graphite particles. It has been shown that by varying the process parameters, different hardness values between around 130 HV and 180 HV can be achieved, with which contact resistances of around 10 mW at low compressive forces and around 4 mW at higher pressures can be measured.

With regard to the application, the coatings should, on the one hand, be only slightly abraded during the mating cycles and, on the other hand, be resistant to mechanical loads due to their high hardness. To achieve this, they should have coefficients of friction in the range of 0.2 to 0.4 and a hardness of at least 120 HV, which can be realised with the developed systems. Work is currently underway to further increase the service life under the influence of contact force and friction cycles.

Kayla Johnson, fem Research Institute Precious Metals and Metal Chemistry, dealt with simulations of electroplating production processes for resource-saving optimisation using the COMSOL Multiphysics® software, as it can be used for electroforming, for example. The software is equipped with a so-called electrochemistry module for such simulations. This software utilises a physics-based system for finite element analysis (FEA), whereby all spatial dimensions can be considered. This allows the influence of the parameters cell geometry, electrode reaction kinetics, operating voltage/current, temperature and electrolyte composition to be analysed. Johnson optimised the details of electroforming in collaboration with a contract coater. The simulation was supplemented by a camera system for recording the loading status of electroplating points. This meant that the distances between the components and the anodes could also be included in the calculations, allowing, for example, the layer thicknesses to be determined by simulation depending on the rack placement on the individual components. In practice, the software provides the values determined to the system operator, who then decides on the further handling of the coated components. In another project, copper-tin depositions on real components were simulated and compared with real depositions. By using apertures, it was possible to fulfil the requirement of a specific layer distribution in terms of thickness and composition in this study.

The levelling of the micro-surface plays an important role in the use of additively manufactured metal parts. In his presentation, Matthias Kroll, Plasotec GmbH, gave an insight into the possibilities for deburring, polishing and cleaning such parts using electrolytic plasma polishing. As he emphasised in his introduction, the processing technologies of deburring, cleaning and polishing can be achieved with a single process. The technology was introduced into practice from a ZIM project in 2000 based on developments in the military sector. The process is used, for example, for stainless steels, cobalt and nickel-based alloys, copper alloys or aluminium and titanium, i.e. for a wide range of frequently used metallic materials.

Parts to be machined are processed anodically in an electrolyte at voltages of around 320 V and current densities of around 15 A/dm2 to 20 A/dm2. The electrolyte is an aqueous solution with a salt content of around 5 per cent. Levelling is achieved by the current generating a plasma via the micro-tips of the metal surfaces in the first step. This leads to the levelling of the microstructure. At the same time, the surface is cleaned. This makes the processing method ideal for additively manufactured components. According to Kroll, the process is used with great success for medical technology parts, for example, which have to grow into body tissue.

Roland Ratschiller, Electroless Technology AG, used the example of galvanic deposition of nickel and zinc-nickel layers to address the measurement of substance inputs into bodies of water and micropollutants from the field of surface technology. A feasibility study on this topic was carried out in collaboration with companies in Switzerland. Mobile and poorly degradable pollutants can accumulate in bodies of water, and little is known about the resulting effects.

Due to the lack of systematic studies in wastewater-relevant industries on the types of substances used and their discharge, there are major gaps in knowledge on the part of both users and the authorities. According to Ratschiller, the information on ingredients in safety data sheets is often incomplete, as there is no full declaration obligation. It is therefore not possible for the electroplating companies that use them to make a statement about all the substances that are treated in the wastewater. Using the example of nickel and zinc-nickel processes, the path of individual substances from the electroplating plant to the municipal wastewater treatment plant and discharge into surface waters is simulated. Individual process steps are analysed in isolation and simulated in the laboratory.

The investigations show that the metals contained can largely be removed from the wastewater. However, organic components of the electrolytes are released into the environment in greater or lesser quantities with the discharged water. Depending on the substance used, these can then be found in higher concentrations in the water over longer periods of time. This makes it necessary to optimise the required electrolyte additives for better degradability in the future.

The substitution of toxic chemicals such as cyanide and thiourea with less hazardous substances is a relevant issue in the deposition of precious metals such as gold and silver. Another aspect is the recycling of precious metals from electronic scrap and waste from electrolytes. According to the literature, palladium, for example, can be extracted from nuclear waste and gold and platinum can be selectively recovered.

Studies carried out by Lúcia Nascimento, TU Ilmenau, have shown that gold alloys can be electropolished in ionic liquids. This occurs with the formation of organometallic complexes that can be processed. Using simple chemical and electrochemical experiments on graphite, stainless steel and copper, it was possible to recover gold from an electropolishing bath as layers and particles. Tests were also carried out with coatings on copper. From this, the lecturer presented a new approach for the production of precious metal coatings such as hard gold based on new recycling concepts.

Based on the automotive industry, cathodic protective coatings on steels should fulfil further requirements in terms of colour, adhesion or mechanical properties in addition to ever higher corrosion protection. It should be borne in mind that cathodic corrosion protection is usually provided by a multi-layer system, the individual layers of which must be well matched to each other in order to fulfil the requirements of the overall system. In her presentation, Dr Christine Rohr, SurTec International, dealt intensively with how individual layers can (partially) fulfil the requirements, which requirements are made and what should be taken into account so that the overall system can also meet the outstanding requirements made of wheel bolts or locking screws, for example.

For screws, friction on the relevant surfaces (especially in the head area) plays a decisive role in achieving the necessary clamping force. Depending on the coating process, the friction is achieved via the coating combination of metal and passivation/sealing or through additional lubrication. Locking screws are equipped in such a way that a bond between the screw and the component prevents the required locking against unintentional loosening. The lecturer demonstrated that optimum locking is achieved when the adhesive breaks under load and the passivation on the zinc-nickel coating does not peel off.

The European Commission's mandate to the ECHA on 11 October 2023 to develop a restriction proposal for chromium(VI) compounds will provide a way out of the current situation. However, there are still many uncertainties about the future limit values and a possible obligation for substitution, according to Dr Julius Gröne, Matthews International Corporation.

In view of these uncertainties, Gröne believes it is crucial to keep looking for alternatives. In this context, a test rig has been developed that allows the suitability of surfaces for gravure and embossing applications to be analysed in detail using different materials. Various electrochemical and physical coatings were tested and compared with different materials. These include various types of nickel and nickel alloy deposition on the electrochemical side and laser cladding on the physical side.

With the increasing electrification of mobility, the use of aluminium as a construction material has excellent growth potential, particularly due to its low density and diverse manufacturing and shaping options. As examples of aluminium components in electrified mobility applications, Dr Julia Dukwen, Aalberts Surface Technologies GmbH, cited housings for batteries or auxiliary units, as well as aluminium coils in electric motors.

In addition to the usual requirements, the aluminium components must also meet electrical insulation requirements for numerous applications. Anodisation is the method of choice for creating appropriate potential barriers on aluminium components for mass applications. The properties of the anodised layers are influenced by the composition and microstructure of the alloy in addition to the process-related effects. In addition, the quality of potential barriers is improved by redensifying the conversion layers formed. Additional sealing, for example by means of anodic dip coating, can also be applied as an option.

Dr Dukwen presented the electrically insulating properties of various anodic layers on aluminium materials and the methods used to characterise them. Among other things, it was shown that the increase in breakdown voltage with the layer thickness is not linear, but degressive. Alloys with copper have a lower breakdown stress due to holes in the oxide layer and with silicon due to disturbed layer formation. The forming process also influences the breakdown voltage. Higher barrier layer thicknesses, such as those achieved during anodising with oxalic acid, also lead to higher breakdown stresses, as does the post-compaction of the oxide layers produced.

The surface of aluminium often has insufficient chemical and physical resistance. To improve this, aluminium parts are usually anodised in sulphuric acid. The oxide layer produced has a porous structure that is suitable for colouring the surface and can be sealed using a sealing process, which Can Akyil, MacDermid Enthone Germany, is involved in.

In addition to high chemical and abrasion resistance, choosing the right sealing process according to the different quality standards is crucial to fulfil the requirements in various industries, especially the automotive and aerospace industries. In his presentation, Akyil introduced various sealing technologies and explained criteria for the area of application, production capacity and environmental aspects.

Motivation not only serves to overcome challenges, but also as a powerful enabler for outstanding performance and productivity. According to Manuela Schmied-Wolfsbauer, think.doll Managementcoaching, successful motivation can offer three key benefits for managers and their teams: Productivity increases, staff turnover costs decrease and innovation is driven forward. Consequently, a demotivated team can set in motion a downward spiral that causes considerable damage to the entire organisation.

According to the speakers, only 15 per cent of managers in Germany are familiar with motivation criteria. Motivation is not a luxury, but a must for the success of any organisation. It is important that managers in particular are able to choose the right motivation methods and implement them skilfully.

The electrochemical decomposition of water is a promising technology for providing the energy carrier hydrogen with electrical energy from renewable sources, as Prof. Dr Andreas Bund, TU Ilmenau, emphasised in his introduction. However, the reaction equation for splitting water into oxygen and hydrogen, which appears simple at first glance, has its pitfalls when it comes to electrochemical reaction control.

A look at the energy ratios reveals relatively simple relationships: the energy required to split water decreases as the temperature increases. The process design becomes much more difficult due to the kinetics. The partial reaction of oxygen evolution in particular can be accompanied by considerable losses and therefore requires customised catalysts. The use of precious metals in particular leads to good results. Nevertheless, significant energy losses must be taken into account when developing oxygen.

From a technical point of view, the production of an electrolyser consists of many steps related to electrochemical surface technology, for example the production of catalyst layers or the coating of bipolar plates. According to Prof Bund, one of the most interesting goals of research is the development of a technology in which water is split using sunlight, i.e. photoelectrochemical water splitting.

The widespread introduction of fuel cell technology requires product and process innovations aimed at increasing product performance and/or reducing production costs. The central objective of the AluBiPEM research project presented by Dr Heidi Willing from the fem Research Institute for Precious Metals + Metal Chemistry is therefore the use of aluminium as a substrate material for the key component bipolar plate (BPP).

The objectives of the project include reducing production costs by around 15 per cent compared to steel bipolar plates for small quantities and increasing productivity by around 20 per cent compared to conventional production technology. The project also aims to reduce the system weight of a fuel cell stack by around 45 per cent, to implement a liquid-cooled stack and carry out tests, and to implement an air-cooled stack and carry out field tests. In this joint project funded by the Federal Ministry of Economics and Climate Protection (BMWK), fem is working on the development of a corrosion-resistant galvanic layer structure for the electrical contacting of the bipolar plate with the gas diffusion layer. In addition, the fem is extensively characterising substrate materials and layer systems.

In order to meet the predicted demand for hydrogen for the future CO2-free supply from renewable energy sources, an expansion of electrolysis capacities for the production of hydrogen and thus an upscaling of the production of electrolysers is necessary. The components of the electrolysers must be cost-effective and fulfil high requirements in terms of stability and service life. A promising strategy for the cost-effective production of the metallic components of a stack is the functionalisation of the base material with electroplated protective layers. In his lecture, Dr Martin Leimbach, TU Ilmenau, presented the work carried out at the TU Ilmenau on this topic.

The coating systems must both protect the base material (e.g. stainless steel) against corrosion and have a low contact resistance in order to avoid ohmic voltage losses. As part of the StacIE (Stack - Scale up - Industrialisation PEM Electrolysis) project, layer systems for bipolar plates and porous transport layers are being researched and tested under real conditions in an electrolyser stack. The test stack allows parallel electrochemical investigations in five cells with simultaneous monitoring of pH value, conductivity and temperature for each half-cell. Using polarisation tests in combination with electrochemical impedance spectroscopy and the sensor data, statements can be made about the long-term stability of the coated components. Gold and post-treated tin-nickel layers have proven to be promising candidates for the bipolar plate, while the porous transport layer made of titanium is functionalised with platinum for better bonding to the catalyst.

Two low-temperature electrolysis processes are commercially available for the production of green hydrogen: alkaline electrolysis (AEL) and electrolysis using a proton exchange membrane (PEMEL). According to Dr Stefan Kölle from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA, alkaline electrolysis is an established technology, although it is currently less able to cope with the volatile dynamics of renewable energy. PEM electrolysers, on the other hand, have good partial load capability and can be operated at high current densities with very good efficiency levels.
However, the technology is dependent on precious metals such as iridium on both the cathode and anode sides. For the anode side, iridium oxide has the best property profile in terms of electrochemical activity and resistance. However, iridium is one of the rarest elements of all. Currently, around 0.67 grams of iridium are required per kilowatt of power for a PEM electrolyser, which results in very high material costs and therefore stack costs.

In order to be able to bring PEMELs onto the market competitively on a large scale, the use of iridium must be significantly reduced. In the research project IREKA - Iridium-reduced anode catalysts for PEM water electrolysis, which is being led by the Leibniz Institute for Catalysis e. V., researchers at Fraunhofer IPA are working on the development of electrodeposition processes for the production of catalyst layers with the aim of producing catalyst materials and layers with the lowest possible iridium content.

AEM electrolysis (AEM - Anion Exchange Membrane) has the potential to make the decarbonisation of industry competitive by switching to green hydrogen as an energy carrier, as it combines dynamic operation and a cost-effective electrolyser design without precious metal catalysts. Direct coatings on anion exchange membranes for efficient water electrolysis are being investigated as part of the AEM-Direkt project funded by the German Federal Ministry of Education and Research as part of the H2Giga lead project.

In his presentation, Nils Ulrich from Dr.-Ing. Max Schlötter GmbH & Co KG presented the electroless deposition of catalytically active nickel coatings and discussed the results of stability and performance tests. These coatings were analysed in a specific electrochemical cell with regard to their effect on cell potential and the proportion of external gas in the hydrogen at the anode.

According to Dr Sebastian Etschel, Schaeffler Technologies AG & Co KG, the development of electrolysers and fuel cells plays a key role in the transition of the global economy from fossil fuels to green energy sources. In particular, the coating systems used for system-relevant components are of central importance when it comes to improving the service life, performance and cost-effectiveness of electrochemical components.

The high-performance coatings sought for components such as bipolar plates in electrolysers should have high corrosion resistance in a wide pH range, high adhesive strength and low electrical contact resistance. In order to achieve an economically competitive solution, it is also necessary to dispense with critical raw materials. The focus here is primarily on the components on the anode side, as materials such as titanium are usually used as substrates, which are also provided with a coating containing precious metals.

The coating approach investigated for this application includes the porous transport layer (PTL) as an essential component in an electrolytic cell to ensure mass transport and electron conduction. Various platinum deposition technologies on porous titanium substrates were analysed and the different variants were evaluated in terms of their electrical contact resistance.

Dr Thomas Weimer, Spiraltec GmbH, is looking at the possibility of using hydrogen to recover metals and acids from process solutions. The new recovery process is being explicitly implemented for a solution for pickling ferrous materials. This has resulted in the development of a possible overall process for the future maintenance of metal pickling without the need for chemicals and with minimal waste water.