Dresden 2017 – wissenschaftliches Programm
MM 18: Topical session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Experimental Characterization
MM 18.1: Topical Talk
Montag, 20. März 2017, 17:30–18:00, BAR 205
Experimental investigations on the relationship between crystallographic character of grain boundaries and their functional and mechanical properties in various engineering materials. — •Stefan Zaefferer, Dayong An, Zhangqi Wang, Fady Archie, and Guillaume Stechmann — Max-Planck-Institut für Eisenforschung
Grain boundaries are important defects in crystalline solids because they influence a large number of properties, like strength of ductile materials, fracture resistance and corrosion resistance of various metals, or efficiency losses in polycrystalline solar cells. The exact correspondence between the properties and the crystallographic nature of grain boundaries is in many cases not well understood which is mainly due to the fact that grain boundaries are characterized by 8 degrees of freedom, namely 5 rotational parameters and 3 translational ones. The translational parameters are very difficult to measure and it is not clear whether they are independent of the others. The rotational parameters, that is the grain boundary misorientation (3 parameters) and the grain boundary plane, can however be measured using 3D or pseudo-3D orientation microscopy. With these techniques we are able to study the influence of all parameters on grain boundary properties. In the presentation we will introduce the various techniques and show application examples. In particular we will present results on the corrosion of grain boundaries of austenitic stainless steels in aqueous acid solutions and in salt melts, on fracture resistance in DP steels and on the influence on the performance of CdTe solar cells.