Materials Science Forum, Vol.495-497, 639-644, 2005
Characteristics of hot compressed magnesium alloy AZ31 with initial textures analyzed by orientation mapping
Orientation mapping based on EBSD technique was applied to reveal the orientations of new grains and their relationships to the surrounding matrices, to analyze Kikuchi band contrast and the influence of strain rates on local orientation evolution. This information is used to understand the dynamic recrystallization mechanism and the relative contribution of plastic slip versus grain boundary glide or grain rotation related with super-plasticity. For this purpose samples with different initial textures were deformed by (quasi-)plain strain compression at two strain rates. It is suggested that the dynamic recrystallization in this alloy proceeds in continuous way by progressive subgrain rotation. No evident non-basal slip of < a+c > was observed by referring texture evolution in the sample with initial basal texture. A high strain rate promotes more contribution of plastic slip accompanied by fast orientation changes. The fact that groups of grains with very similar orientations in basal oriented samples is discussed in terms of viscous flow.