Hochpolymere Werkstoffe. Aufbau – Eigenschaftsbild – Anwendung

High Polymers: Structure — Properties — Application . The close relationship between the Institute of Materials Technology and the State Institute of Materials Testing gives an informal and continual active exchange of research on materials, materials testing and education. A special correlation in the field of high polymers was reached. Outstanding examples from the important research work over a period of the last five years have been singled out, and the development of the subjects the extent of the problems involved, the complexity and the results of the subject have been outlined. It is here, chiefly a matter of investigation of the relationship between the structure or duro-plastic multicomponent systems, the dependence of molecular orientation and electrostatic charge of thermoplastic plastic materials on the conditions of processing, as well as those of the question of the properties of the components of Duro- and Thermoplastics. The research work which had been planned and begun concentrated as usual on the related applications, the reasonableness of engineering processes involved in the range — row-stuff and the end-product. It is, however, readily recognizable, that the interdisciplinary collaboration in these tasks will be intensified in the future.     

SiNx-Submikrometerschichten – Parameteroptimierung –

SiN_x-submicrometer coatings – Optimization of the film properties – The influence of the deposition conditions on the properties of SiN_x-coatings was investigated. The characterized SiN_x-coatings were deposited by the help of reactive magnetron sputtering. Gas pressure and film thickness were varied. Scanning electron microscopic views of the cross sections show a columnar structure varying with the deposition parameters. The different structures are comparable to the known structure zone models. There is a transition from dense structures to open columnar structures with increasing gas pressure. The Microstructure of coatings also changes with increasing film thickness. Especially deposition conditions promoting shadowing effects lead to a large growth of the column diameter with increasing thickness. The intrinsic stresses and the ultramicrohardness of the coatings change with changing gas pressure, too. Dense structures have high intrinsic stresses and a high hardness while coarse columnar structures have low intrinsic stresses and a low hardness. The influence of the deposition parameters on wear behaviour and adhesion of the SiN_x-coatings was investigated by cavitation tests. Dense coatings with high intrinsic stresses show adhesion failures, and coatings with lower stresses and coarse columnar structures fail because of their lower intrinsic stability. Thus, there is an optimum gas pressure, at which the best properties are reached. It can be shown that with decreasing film thickness adhesion increases.     

Korngrenzenphasen in Schmelzlötverbindungen,Bildung – Schmelzen – Zusammensetzung

At the thermal solidification of metallic and non metallic melts with technical purity the thermal solidification of polycristalline substances is carried out under beginning of the corresponding grains and the beginning of a grain boundary phase between these grains. For the examination of the kinetics of melting thermally the authors used the gradual heating of eutectic SnPb solder pearls in an oxygen free heat up liquid. The developed method for the ultrasound supported dispersion of solid solder metals in an oxygen free heat up liquid was used for the separated thermal melt of the grain boundary phase and the grains.