Wittke K.,Gablerstrasse 23 |
Scheel W.,Gablerstrasse 23
Materialwissenschaft und Werkstofftechnik | Year: 2014
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. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Wittke K.,Gablerstrasse 23
Materialwissenschaft und Werkstofftechnik | Year: 2013
In the article a method for the material modelling is described under application of visually transparent materials of the thermal and chemical solidification processes when welding and soldering. All solidification processes carried out independently of the form of the primary crystals, first about the planar one, then cellular and in the end dendritically growth the solidification structure. It is determined by the chemical composition of the weld and soldering good, the weld, soldering, crystallization or solidification speeds and by the temperature gradients at the solidification front particularly. The vacancy concentration is made by the temporary formation of so-called zipper primary grain boundaries in the solidification structure when welding. Among other things a preferential growth direction of the primary crystals explains itself by the fast growth of so-called victim crystals which completes the known theories of the preferential growth. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.