In this year's European Capital of Culture Chemnitz, materials and surface engineers once again came together for the Materials Technology Colloquium on April 2 and 3, 2025. Participation in the annual event was greater than ever.
The 24th Materials Technology Colloquium (WTK) was organized by the Institute of Materials Science and Engineering (IWW) at Chemnitz University of Technology. The motto of the event was "Academia meets Industry". The invitation was accepted by 220 national and international participants, the highest attendance at a WTK to date. The organizers are rightly proud of this result.
In his opening speech, Prof. Dr. Thomas Lampke, Professor of Materials and Surface Technology at Chemnitz University of Technology, referred to the development of the WTK into an international conference, which is now held almost entirely in English. He also emphasized his confidence in the scientific community.
Professor Dr. Jonas Hensel, Dean of the Faculty of Mechanical Engineering at Chemnitz University of Technology, expressed his pleasure at being able to give a welcome address at the WTK on the second day of his term of office. In particular, he emphasized the ongoing commitment of the IWW and the importance of the WTK for the industry as a platform for scientific exchange.
Prof. Dr. Lech Pawlowski, University of Limoges/France, who holds an honorary doctorate from the Faculty of Mechanical Engineering and is an international expert in thermal coating, also gave a welcome address with good wishes for the event.
True to the motto of this year's WTK, the lecture program began with the following keynote speeches by start-ups and industrial companies:
- Amazemet (Warsaw): Development and supply of ultrasonic atomization devices
- 3D-Micromac AG (Chemnitz): Laser micromachining of diverse materials using short-pulse and ultrashort-pulse lasers as well as short-wave lasers
- Polytec GmbH (Waldbronn): Laser Doppler vibrometry
- Chemnitzer Werkstoffmechanik GmbH (Chemnitz) together with Kammrath & Weiss GmbH (Schwerte): Development of optical measurement methods with digital image correlation, for the in-situ characterization of material behavior using light or electron microscopy
- CMMC GmbH (Chemnitz): Development of a new casting technology for the production of AMC composite powders (aluminum matrix composite)
The companies Kulzer GmbH, Netzsch Gerätebau GmbH (thermal analysis, emission analysis), Brenscheidt Galvanik Service GmbH (consulting, laboratory services), Diamant Polymer GmbH (manufacturer of polymers, composite materials, impregnating agents), Carl Zeiss Microscopy GmbH and Cloeren Technology GmbH (metallography and sample preparation) also presented themselves in the industrial exhibition in the foyer of the lecture rooms.
The lecture program was supplemented by 13 poster contributions. These posters were also presented in the foyer and introduced in short talks. A nice tradition is that the three best posters, which were selected in an electronic vote, are awarded prizes in the evening event on the first day of the conference. First place went to Pratidhwani Biswal (Fraunhofer IGP Rostock) on the topic of "Thermally sprayed coating for soilless cultivation". Second place went to Robert Rimpel (TU Chemnitz) with the topic "Evaluation of the Schaeffler diagram as a prediction model for property determination in functionally graded manufacturing using plasma powder cladding" and third place to LukአVáclavek (University of Olomouc) with the topic "Characterization of mechanical properties of CrN-TiN coatings deposited using advanced sputtering methods".
The conference program contained a total of 62 presentations. Some of the presentations are described in more detail below.
Best Poster Award, with Prof. Dr. Thomas Lampke (l.)
Composite materials
In his overview lecture, Prof. Dr. Bodo Fiedler, University of Hamburg, looked at the major challenges with regard to the correct determination of mechanical, electrical and thermal properties of high-performance composites (fiber-plastic composites). In particular, he reported on the approaches for measuring electrical properties and thermal conductivity. These fundamental investigations are supplemented and continued by mathematical methods.
In the next presentation, Dr. Andreas Todt, Fraunhofer ISC Münchberg, dealt with innovative tube structures for small satellites. By using a resin infiltration process, followed by pyrolysis and siliconization, the textile preforms were converted into the ceramic composite material C/C-SiC. The resulting tubular C/C-SiC demonstrators meet the stringent requirements of the aerospace industry, such as low weight, high strength and low thermal expansion.
Prof. Dr. Alexander Delp, University of Dortmund, presented investigations to characterize the moisture and temperature-dependent deformation behaviour of the vulcanized fibre composite material. ACC (all-cellulose composite) vulcanized fibre, a catalytically converted cellulose paper, exhibits similar material properties to thermoplastics, but shows higher abrasion and temperature resistance, antistatic properties and also sensitivity to moisture. It has been demonstrated that the influence of paper formulations on forming properties can be identified.
Additive manufacturing
The presentation by Kai Treutler, Clausthal University, dealt with the development of an anti-wear coating that does not contain any nickel or cobalt components. Iron aluminides that provide sufficient wear protection were investigated, and it is possible to apply an iron aluminide wear coating to a steel substrate using plasma powder cladding. Since the elements iron and aluminum alone are not sufficient to obtain a high-quality wear protection coating, additional alloying elements and their influence on the microstructure were investigated.
Chemical and galvanic surface technologies
In his overview lecture on electroforming, Dr. Markus Guttmann, KIT Karlsruhe, provided information on known industrial applications and the development of manufacturing processes for the production of micro- and nanostructured shims made of nickel for the injection molding of plastic, metal or ceramic components. In particular, he spoke about applications for solar cells on which a rose petal structure was created to reduce reflection. This significantly increases the light yield of the cells. Reflection can thus be reduced to less than 1%. The natural microstructure (rose petal) can be produced by laser structuring for large-scale use.
One of the biggest challenges in a future fusion power plant is the extraction of heat from the so-called "divertor targets", the most important components in the breeder module, reported Dr. Carsten Bonnekoh, KIT Karlsruhe, afterwards. The basic concept uses tungsten as the plasma-side material and a copper alloy for the underlying heat sink. At KIT Karlsruhe, the connection is realized by electrodeposited intermediate layers.
Another presentation in this session by Dr. Mehri Hashemzadeh, Innovent Jena, dealt with the influence of oxalate and citrate additives on so-called soft sparks in the PEO (plasma electrolytic oxidation process) of the Al6082 alloy. Sodium oxalate prolonged the duration of the current-constant mode, while sodium citrate shortened it. Both additives improve wear resistance and provide excellent corrosion resistance after 1,000 h of salt spray exposure.
Igor Danilov, TU Chemnitz, presented a 2D simulation of the barrier layer formation during the initial phase of PEO. Multiphysics simulations are a suitable method to better understand the dynamics of the PEO process and to evaluate the transient layer growth on the anode surface. The high-field model was used to calculate the growth of the oxide layer as a function of the transmitted electrical charge.
Laboratory tour at the IWW
Nickel alloys
Nickel and nickel alloy foams are excellent carrier materials for many different applications, including filters, catalyst materials and battery electrodes. Dr. Anton Salomon, Fraunhofer IFAM Dresden, spoke about investigations into surface modifications of nickel foams for various applications. Customized heat treatment as the final process step is crucial for the stability of the alloyed foams. The process chain, surface treatment, alloying and heat treatment as well as the application of nickel foams in areas such as water treatment and filtration were examined.
Hydrogen technology
Electroplated, porous layers for the functionalization of electrodes for alkaline water electrolysis were presented by Dr. Andrea Zaffora (University of Palermo). He proposed cathodic and anodic porous transport layers functionalized by optimized electrodeposition processes to work in alkaline environments. Platinum group metal-free nickel-containing catalytic layers were investigated using stainless steel mesh as a substrate.
Sebastian Kaiser, BAM Berlin, presented a study on the evaluation of welding process conditions and weld seams for pressurized hydrogen pipelines. As hydrogen can be absorbed in the pipeline material, there is a risk that the hydrogen solubility of the materials will increase significantly if welding work is required on pressurized pipelines.
High-profile plenary speeches, coatings made from recycled powder waste
On the morning of the second day of the conference, the plenary speeches by Dr. Lukas Wojarski, Technical University of Dortmund, on the topic of "Digital laboratories in university teaching" and by Prof. Dr. Sebastian Härtel, BTU Cottbus, who presented pioneering concepts for the recycling of metallic chip waste using additive technologies, attracted a great deal of attention. This also applied to the contributions on human-centred digitalization, which dealt with questions of sustainable human-technology relationships, the acquisition and systematization of expert knowledge and the adaptive visualization of process parameters, e.g. for the design of coating processes. This makes it possible to make comprehensible decisions that lead to efficient and effective processes.
The final lecture was given by Prof. Dr. Shrikant Joshi from the University of Applied Sciences West, Trollhättan/Sweden, who, as a member of the Hall of Fame of the Thermal Spray Society, is once again completing a longer research stay at the IWW as a guest scientist and is involved in a wide range of scientific activities. Using the example of thermal spraying, he provided interesting insights into the development of surface technology to overcome technological challenges that require intensive basic and application-oriented research. The striking properties of coatings made from recycled powder waste also made the experts sit up and take notice.
At the end of the 24th WTK, Prof. Dr. Guntram Wagner, TU Chemnitz, IWW, Chair of Composites and Material Composites, thanked all speakers for their interesting scientific contributions and cordially invited them to the 25th WTK in 2027.
The evening event at the end of the first conference day took place at the Hotel Chemnitzer Hof and brought everyone together for a cozy get-together. Chemnitz is the European Capital of Culture in 2025, so the organizers built a bridge between the 24th WTK and the diverse events taking place in Chemnitz that year. During the evening event, Dr. Barbara Waske from the Chemnitz Industrial Museum gave an informative presentation on the structural change of the industrial city of Chemnitz in recent history with all its ups and downs. The exhibition of the same name in the Chemnitz Industrial Museum "Tails of Transformation - Stories of Change" is part of the Capital of Culture program. The speaker succeeded in establishing the interaction between society, technology and culture using the example of Chemnitz and other European cities similarly affected by change. The colloquium concluded with an optional tour of the laboratory at the IWW, which was taken up by a number of people before they too set off on their journey home. The all-round successful event once again impressed with an appealing lecture program, an informative industry exhibition, entertaining pitches in the poster show and a successful evening event.
