Knowledge building Knowledge acquisition is the driving force behind research: larger projects, often supported by PhD theses, are carried out in the framework of the knowledge building programme. Furthermore, collaboration can add valuable expertise. The results obtained provide useful insights for smart product development and finally ideas arise for portfolio renewal. Knowledge building is the key activity fuelling R&D.
In 2020-2021, significant progress has been achieved in the surface, metallurgy and application related research of the knowledge building programmes. Some examples of the numerous realisations: — Mechanical properties of zinc coatings are well-known and have been studied in detail over the past decades. Enhancement of the corrosion resistance can be achieved by adding Mg and Al to the Zn coating. The markedly superior corrosion, friction behaviour and wear resistance of ZnAl-Mg coatings has been reported to be related to the element’s distribution and strong refinement of the complex microstructure. However, in-depth knowledge of the local mechanical properties of individual microstructural constituents with respect to the crystallographic orientation of the phases is lacking. Knowledge building studies during the past 2 years aimed to contribute to a better understanding of the microstructure, hardness and elastic modulus of the main eutectic microphases in the complex solidification structure of two Zn-Al-Mg systems i.e. Zn-5Al and Zn-3.7Al-3Mg coatings. Then,
the anisotropic mechanical properties of pure phases matching the composition of the different phases in these coatings were examined using nano-indentation coupled with EBSD analyses. Finally, Voigt, Reuss and Voigt-Reuss-Hill models were used to predict the hardness and elastic modulus of the eutectic phases in the two coatings using the individual properties of the pure phases. In a next step, SEM in-situ deformation techniques were used to study the mechanical properties of these new coatings and correlate the results with the findings on the mechanical properties of the individual phases. Finally, these data were used to validate a FEM model predicting the cracking behaviour of the coating depending on the phase composition and distribution. — High Strength Steels offer a unique opportunity to reduce weight in heavy duty machinery such as trucks, trailers and agricultural machinery. However, their fatigue behaviour can be lower than expected in certain applications. By developing a numerical FE simulation framework, the microstructural features such as phase fraction, grain size distribution, texture, inclusions, etc. on the ‘High Cycle Fatigue’ and ‘Low Cycle
