Gold plated tungsten wires are used in a wide variety of applications ranging from medical devices to high frequency signal transmission. Thin wires place special demands on the plating process and this study aims to understand how surface properties affect the deposition of gold. Tungsten single crystals and wires with different dimensions were therefore studied in alkaline cyanide electrolyte with and without gold cyanide complexes, using electrochemical impedance spectroscopy under stationary conditions. Measurements were made as function of potential and steady-state currents, capacitances and resistances were extracted from the data. The results show that deposition of gold takes place close to the equilibrium potential irrespective of crystal orientation and morphology of tungsten. Concentration dependences show that the deposition rate is first order with respect to the concentration of gold complex and inversely related to the free cyanide concentration. These results confirm that the reaction sequence includes a chemical dissociation step prior to electron transfer. For partially gold covered tungsten wires, the rate of hydrogen evolution was found to be enhanced compared with a bare tungsten wire and pure gold metal, which is explained by the formation of three-phase junctions where water splitting and electron transfer occur at different sites.

Aluminum is a very attractive material for bipolar plates in proton exchange membrane (PEM) fuel cells due to its low weight, excellent thermal and electrical conductivity, as well as good recyclability. However, to achieve the necessary low contact resistance and corrosion stability, a suitable surface coating is needed. In the present study, two different material systems were evaluated, electroless deposited NiP based coatings and high-power impulse magnetron sputter-deposited (HiPIMS) Ti based coatings. The addition of a 100 nm amorphous carbon (a-C) top-layer on the NiP and Ti based coatings was also evaluated. The electrochemical corrosion behavior of the coatings was evaluated in simulated PEM environments. Potentiodynamic and potentiostatic polarization experiments revealed that the HiPIMS Ti coatings performed better than NiP coatings. The addition of the a-C top-layer on the other hand was found to be detrimental to the Ti based coatings resulting in a corrosion current density of 3.6 mu A/cm2. The opposite was observed in the case of the NiP based coatings where the addition of the a-C layer decreases the corrosion current thereby increasing corrosion resistance. Further analysis showed that defects in the coating as well as the presence of a Fe-Si rich particles in the Al substrate were the initiation points for the corrosion attacks to occur.

The aim of this project was to assess the thermal conductivity of polyethylene (PE) filled with carbon black (CB), specifically for geothermal pipes. The project explored the potential modification of PE’s thermal conductivity by incorporating recycled textile fibers. Different types of shredded recycled fibers were tested, including two types of polyamide fibers with varying contaminations and one type of polyester fiber. Following several preparation steps, various composite materials were manufactured and compared to bulk PE using various testing methods: Differential Scanning Calorimetry analysis (DSC), mechanical testing (flexural and tensile), and laser flash analysis (LFA). The results revealed alterations in the mechanical properties of the composite materials in comparison to PE filled with CB. The LFA tests demonstrated the effectiveness in reducing polymer thermal diffusivity at higher temperatures, particularly when the material was loaded with recycled polyester fillers.

Thin wires of molybdenum coated with gold are used for space applications and the adhesion of the gold layer is decisive for their use. The surface morphology of the wires is determined by the manufacturing process and preferential orientation of single crystal surfaces is expected. In this work three different single crystal surfaces were studied together with a 20 μm molybdenum wire to elucidate the importance of surface morphology on the electrodeposition process for gold. Electrochemical impedance spectroscopy was used to study the molybdenum samples in the absence and presence of gold cyanide complexes. The results show large pseudocapacitance prior to gold deposition, indicating the presence of a thin molybdenum oxide film on the surface. Thus, the electrodeposition takes place on the surface oxide and is afflicted with a nucleation overpotential. The overpotential is only slightly dependent on the single crystal orientation, while it is more negative for the wire. The adhesion of gold on the flat single crystal surfaces is weak but marginally better on the wire. This clearly shows that strong chemical binding to the surface is absent and that other processes, such as physical interlocking of the gold layer is necessary for good adhesion.

This study provides principles for designing new corrosion resistant high entropy alloys. The theoretical framework is a percolation model developed by Newman and Sieradzki that predicts the ability of an alloy to passivate, i.e., to form a protective surface oxide, based on its composition. Here, their model is applied to more complex materials than previously, namely amorphous CrFeNiTa and CrFeNiW alloys. Furthermore, the model describes a more complex passivation process: reforming the oxide layer above the transpassive potential of Cr. The model is used to predict the lowest concentration of Ta or W required to extend the passive region, yielding 11–14 at% Ta and 14–17 at% W. For CrFeNiTa, experiments reveal a threshold value of 13–15 at% Ta, which agrees with the prediction. For CrFeNiW, the experimentally determined threshold value is 37–45 at% W, far above the predicted value. Further investigations explore why the percolation model fails to describe the CrFeNiW system; key factors are the higher nobility and the pH sensitivity of W. These results demonstrate some limitations of the percolation model and offer complementary passivation criteria, while providing a design route for combining the properties of the 3d transition metal and refractory metal groups.

"The Schwäbisch Gmünd Prize for Young Scientists 2023." Transactions of the IMF, 101(3), p. 113

"New key persons when research institute on precious metals turns 100 years old." Transactions of the IMF, 101(1), pp. 2–3

The electrical contact resistance is a key parameter for optimising both the bipolar plate of the polymer electrolyte membrane fuel cell (PEMFC) and the electrical contact of the power terminal of the stack. The contact resistance is affected by the conductivity, roughness, and hardness of the two contacting surfaces. Here, new, application-specific contact resistance measurement methods are proposed for both the stack power terminal, and the bipolar plate. The proposed methods are compared to methods from references as well as standards, and it is concluded that the uncertainty of the measurements can be reduced by changing the measurement setup, and that the influence of probe resistance on measurement results can be eliminated. Furthermore, the effect of different accelerated durability tests on the contact resistance of the power terminal is examined both on test coupons and on a prototype screw connection with an electroless NiP and an electroplated NiSn coatings. As expected, the NiSn coupons gives lower contact resistance after ageing as compared to the NiP. However, the increase in contact resistance seen on coupons after ageing is not observed on the prototype screw connection.

"Prize giving and annual meeting 2021 of the European Academy of Surface Technology." Transactions of the IMF, 100(1), pp. 4–5

Proton exchange membrane fuel cells (PEMFCs) are an important alternative to fossil fuels and a complement to batteries for the electrification of vehicles. However, their high cost obstructs commercialization, and the catalyst material, including its synthesis, constitutes one of the major cost components. In this work, Pt-Ni and Pt-Ni-Mo(O) nanoparticles (NPs) of varying composition have been synthesized in a single step by pulse electrodeposition onto a PEMFC's gas diffusion layer. The proposed synthesis route combines NP synthesis and their fixation onto the microporous carbon layer in a single step. Both Pt-Ni and Pt-Ni-Mo(O) catalysts exhibit extremely high mass activities at oxygen reduction reaction (ORR) with very low Pt loadings of around 4 mu g/cm(2) due to the favorable distribution of NPs in contact with the proton exchange membrane. Particle sizes of 40-50 nm and 40-80 nm were obtained for Pt-Ni and Pt-Ni-Mo(O) systems, respectively. The highest ORR mass activities were found for Pt67Ni33 and Pt66Ni32-MoOx NPs. The feasibility of a single-step electrodeposition of Pt-Ni-Mo(O) NPs was successfully demonstrated; however, the ternary NPs are of more amorphous nature in contrast to the crystalline, binary Pt-Ni particles, due to the oxidized state of Mo. Nevertheless, despite their heterogeneous nature, the ternary NPs show homogeneous behavior even on a microscopic scale. (C) 2022 The Author(s). Published by Elsevier Ltd.

The biennial conference, European Pulse Plating Seminar was scheduled to be held in early March for the tenth time as a joint event with the annual conference of the European Academy of Surface Technology, EAST Forum. The pandemic did not allow the conference to be held as planned. Instead, it was integrated with the 14th International Workshop on Electrodeposited Nanostructures (EDNANO, 9–11 June 2022, Krakow, Poland). This became an extended event with 25 oral presentations and 16 posters. Many attendees highlighted the value of again being able to meet and interact at a physically attended scientific event. The conference had 44 attendees from 11 different countries. The organising committee was chaired by the Polish representative of EAST, Professor Piotr Zabinski, Faculty of Non-Ferrous Metals, AGH University of Science and Technology, Krakow, Poland (Figure 1). The integrated pulse plating session was organised by the Austrian representative of EAST, Dr. Wolgang Hansal, RENA Technologies Austria GmbH.

In the valley between two pandemic peaks, a relatively big group of professionals working in the field of metals was very excited as it became possible to realise one of the few physical international conferences on metallurgy and surface technology in 2021. It was achieved during 9–10 November in Espoo, Finland. IPMS 2021, held in honour of Prof. Emeritus Kari Heiskanen with the sub-title ‘Metallurgy as a tool for challenges in circular economy’, was organised as a hybrid conference with 140 physical attendees and another 60 attending online. The organising committee was chaired by the Finnish representative of EAST, Prof. Mari Lundström, Department of Chemical and Metallurgical Engineering, Aalto University, Finland (Figure 1). The highlight of the conference was Prof. Emeritus Kari Heiskanen giving an honorary lecture to cover his ‘most glorious moments of my career’ (Figure 2). Regardless of his long career both in industry aswell as inacademyasprofessor of Recycling and Minerals Processing (in Aalto University, previously Helsinki University of Technology, Finland), he surprised the audience by revealing that the presentation would actually not discuss anything about the glorious moments, but rather focus on the several wicked problems of the mineral industry that actually require a systemic approach to be mitigated. In his talk he stated that the societal development is moving towards electrification and a carbon neutral future with a lot of hype, promises andexpectations; however, there is lackof a proper understanding of the realities that themining industry is facing in fulfilling the existing and unpredicted volumes in metals production. Prof. Emeritus Heiskanen revealed that in the coming years, a clear majority of metals must be produced from primary resources, while recycling will be only a partial solution. At the same time, water availability and pollution along biodiversity issues are causing concerns, and environmental requirements are becoming stricter. To answer for the global need of metals and improve resource efficiency, more information about the ore and gangue minerals, and their behaviour, is needed, while considering also water availability, tailings handling and resource efficiency in a holistic manner. In order to solve at least part of the challenges, high mineralised volumes should be identified and beneficiated, large volumes of already mined under cut-off-grade materials used and operational resilience of the beneficiation plants improved. Instead of defining efficiency based on a singleunit process like crushing, grinding or flotation, holistic processing including management of tailings, water and cutoff material should be considered systematically. Furthermore, future metal demand will have impacts outside of techno-economical processing, i.e. on biodiversity and sustainability. He highlighted that the systematic understanding of all of these aspects is necessary to develop truly sustainable metals processing for electrification, and digitalisation is playing a key role in that transformation. He finalised his presentation by concluding that the realisation of a carbon neutral future is a bit like sailing between the dangers of Scylla and Charybdis from Greek Mythology. The sessions in IPMS 2021 conference were entitled: Keynote, Battery Metals, Mineral Processing, Circular Economy of Metals, Towards Carbon Neutral Metals, EAST Forum, Base and Precious Metals, as well as Process Simulation. In the following, summaries of the Keynote Session and the EAST Forum Session will be given. This will be finalised by a brief summary of the trends reported in the other sessions. Keynote session

This work has explored the surface modification of SiC submicron- and nanoparticles, and its influence on the particles' chemical behaviour and deposition rate in the electroplating of composite Ni/SiC coatings. SiC particles with different sizes (50, 60, 300 and 500 nm) were codeposited in their "as-produced" state. The zeta-potential measurements and alkaline titration for the "as-produced" particles showed differences in chemical behaviour for particles of different sizes, reporting pH buffering effect, even though the particles were inert and chemically the same (SiC). A surface treatment (ST) based on nitric acid was developed in an attempt to set a similar surface state, therefore a similar chemical behaviour in all particles. The zeta-potential measurements and alkaline titration of the "surface treated" particles showed similar results, independently of the size of particles. The pH buffering effect also decreased considerably by the ST. The codeposition rate was modified by the ST differently for each size compared to their as-produced state. The content of SiC50 and SiC500 was doubled (approximate to 2% and approximate to 19%), tripled for SiC300 (approximate to 7%) and more than halved for SiC60 (approximate to 2%). The micmhardness of these composite deposits was linked to the changes in the SiC codeposition.

The European Academy of Surface Technology (EAST) promotes Europe-wide science, research, training, and education in the field of surface technology with the purpose of contributing to the integrat...

Based on an analysis of the competitiveness of the European surface finishing industry, challenges are discussed and future directions for remaining competitive are recommended. The European surface finishing sector should prioritise advanced production technology for new high-tech and high added value products, and take advantage of disruptive changes in society and technology shifts where completely new areas of application of surface technology can arise. To be successful, surface finishers should meet expectations on price, quality, short lead time, innovation ability, complying with legislation, and brand equity. This should be accomplished by increased automation, closer cooperation within the value chain, and improved competence supply. Such a development is extra challenging for the many small-size sub-contractors in the sector. Basically, improved education and improved organisation between applied research, product development, production development and manufacturing are needed. Therefore, the need is strong for pan-European actions to coordinate and expand education on all levels. Higher competence leads to better reliability, quality, and cost-efficiency. Furthermore, the innovation capability will benefit from improved communication between the different actors in the value chain. Finally, coordinated actions are needed to market surface technology/finishing as an interesting and rewarding field in which to make a career. Europe has a strong tradition in surface finishing and the sector is characterised by a significant diversity. The right competence supply and organisation can make ‘cooperative diversity’ a European stronghold.

This study analysed the influence of the codeposition of SiC particles with different sizes: 50 nm, 500 nm and 5 μm, and the type of bath agitation (stirring or ultrasonic) on the electrocrystallisation of nickel coatings. The composites matrix microstructure was analysed by means of SEM, EBSD and XRD, to evaluate the grain size, crystal orientation, and internal stresses and was benchmarked against pure nickel samples electrodeposited in equivalent conditions. The codeposition of nano- and microsize particles with an approximate content of 0.8 and 4 vol.%, respectively, caused only a minor grain refinement and did not vary the dominant < 100 > crystal orientation observed in pure Ni. The internal stress was, however, increased by particles codeposition, up to 104 MPa by nanoparticles and 57 MPa by microparticles, compared to the values observed in pure nickel (41 MPa). The higher codeposition rate (11 vol.%) obtained by the addition of submicron-size particles caused a change in the grain growth from columnar to equiaxial, resulting in deposits with a fully random crystal orientation and pronounced grain refinement. The internal stress was also increased by 800% compared to pure nickel. The ultrasound (US) agitation during the deposition caused grain refinement and a selective particle inclusion prompting a decrease in the content of the particles with the larger particles. The deposits produced under US agitation showed an increase in the internal stresses, with double values compared to stirring. The increase in the deposits microhardness, from 280 HV in pure Ni to 560 HV in Ni/SiC submicron-US, was linked to the microstructural changes and particles content.

Research on fuel cell technology is constantly gaining importance, while global emission requirements are becoming more and more restrictive. For environmentally neutral proton exchange membrane fuel cells (PEMFCs) to become a competitive technology, sustainable infrastructures need to be established. One of the main showstoppers is the utilization of the rare and therefore costly precious metal Pt as the key element in the electrocatalysis of hydrogen and oxygen. A huge amount of research is done on immensely reducing or even replacing Pt for future PEMFC technology. In this research update, the progress on oxygen reduction reaction catalysts in acidic media over the past two years is reviewed, with special attention to their durability.

Ni-based mixed particles composite coatings were designed to achieve superior wear resistance by combining hard carbides and solid lubricants as a reinforcing particles mix. Pure nickel and single-particles composites were electrodeposited in the same conditions for benchmarking. A pre-study was carried out to optimise the current density to avoid loss of process efficiency due to hydrogen evolution. The production process was also improved by employing ultrasounds to avoid porosity and dendritic growth in the metal caused by conductive MoS2 particles. The presence of MoS2 particles led to nanocrystallinity in the nickel matrix, confirmed by electron backscatter diffraction (EBSD) maps and transmission electron microscopy (TEM). The microstructural changes and codeposition in the different composites were correlated to microhardness and pin-on-disc tests. An extremely high hardness was observed in the mixed particles composite (approximate to 1110 HV) due to the combined effect of the nanocrystalline matrix and high codeposition rate (approximate to 15 vol% SiC and approximate to 8 vol% MoS2). The codeposition of MoS2 particles provided a self-lubrication capability to the coating, reducing the friction coefficient compared to pure Ni from 0.15 to 0.07. The wear rate was reduced more than 12 times by the mixed reinforcement compared to pure Ni and more than 6 times compared to Ni-SiC.

In the search for alternative and renewable energies that will finally allow abandoning the use of fossil fuels once and for all, hydrogen energy is among the most promising solutions able to fuel any kind of device independent of its size. The energy cycle of hydrogen needs a large infrastructure of highly efficient catalysts used in both electrolysers, which produce hydrogen gas, as well as fuel cells, where the energy stored in the hydrogen bond is converted into electrical current. The conversion of hydrogen works most effectively in acidic media, where the most effective and chemically stable material is platinum. The low abundancy and associated high cost of Pt make it impossible to provide a large-scale infrastructure using the commercial Pt/C catalyst. Alternatives must be found to substantially reduce the amount of Pt used as catalyst material without compromising its sustainability. A facile electrodeposition process from aqueous media allows the one-step synthesis of a Ni-Mo-Pt alloy for use in both hydrogen evolution reaction (HER) and energy conversion systems such as fuel cells. In a previous study, mesoporous Ni-Pt films were synthesised by electrodeposition and thoroughly characterised towards HER, finding that the reaction in 0.5 M H 2 SO 4 was efficient, stable and reproducible. However, some leaching of Ni into the sulfuric acid was observed under open circuit conditions [1,2]. In this study, molybdenum is introduced into the previously investigated Ni-Pt alloy to increase the stability of the material in acidic media. With respect to the electrolyte used for the synthesis of the Ni-Pt alloy, all bath components were kept the same except for the addition of sodium molybdate and citric acid. The latter complexes Mo(VI), thus enabling its co-deposition. Due to a pH-dependent complexation of Mo(VI) by citric acid, the composition of the Ni-Mo-Pt alloy is strongly pH-dependent and can further be fine-tuned to the needs of the specific application by changing the electrodeposition parameters. The Mo contents obtained reach from 10 at% up to 50 at%. Alloys with the highest Mo content, however, trigger phase separation. Using potentiostatic electrodeposition, continuous thin films of Ni-Mo-Pt are obtained on a Cu-coated Si substrate. However, the growth of globular particles is favoured on a hydrophobic substrate, such as a carbon-based gas diffusion layer (GDL) typically found in a fuel cell set-up. Further, using pulse electrodeposition, nanoparticles with a mean diameter down to 10 nm are successfully obtained. For HER in 0.5 M H 2 SO 4 , Ni rich alloys with low Pt contents (between 1 at% and 5 at%) are investigated, while alloys with higher Pt contents can provide sufficient electrochemical stability for oxygen reduction reaction (ORR) in a proton exchange membrane (PEM) fuel cell. The stability of alloys with varying composition is determined by incubation in 0.5 M H 2 SO 4 . Cyclic voltammetry curves in the same media are performed on Ni-Mo-Pt nanoparticles in order to activate the surface and remove any contaminants as a preparation for tests in a PEM fuel cell, and to determine their electrochemically active surface area (ECSA). The electrochemical experiments are supplemented with microstructural analysis by SEM and XRD. Acknowledgement: This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 764977. Additional support from the Generalitat de Catalunya (2017-SGR-292) and the Spanish Government (MAT2017-86357-C3-1-R and associated FEDER) is also acknowledged. References: [1] K. Eiler, S. Suriñach, J. Sort, E. Pellicer, Appl. Catal. B , 2020 , 265, 118597 [2] K. Eiler, J. Fornell, C. Navarro-Senent, E. Pellicer, J. Sort, Nanoscale , 2020 , 12, 7749