Microstructure and texture development in hydrostatically extruded MgAlZn alloys during tensile testing at intermediate temperatures

Abstract

Tensile testing of hydrostatically extruded round bars of AZ31 and AZ61 has been performed to analyse the flow behaviour as well as the microstructure and texture development as a function of temperature (175–225 °C) and strain rate (0.0001–0.01 s−1). The post-testing microstructure is a result of dynamic recrystallization with varying significance of different texture components. In some cases the resulting textures are found to be similar to those textures that typically develop during extrusion of rare-earth-containing magnesium alloys. Dynamic recrystallization (DRX) and grain boundary sliding (GBS) are considered as the mechanisms that generate the changes in texture. Precipitates can exert a grain boundary pinning effect limiting grain growth. These different mechanisms contribute differently to the texture development if the testing parameters are changed.