Microstructure and texture development in hydrostatically extruded Mg–Al–Zn 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). The post-testing microstructure is a result of dynamic recrystallisation 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 recrystallisation (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 were changed.

Characterization of Microstructure and Mechanical Properties of Mg–Y–Zn Alloys with Respect to Different Content of LPSO Phase

“…This texture favorites the activation of 0001 f gh1120i basal dislocation slip and 10 12g f h10 11i extension twinning, when compression loading is applied along ED at room temperature (RT). [1][2][3][4][5][6][7][8] For Mg alloys with the long-period stacking-ordered (LPSO) phase, the long stacking periodicity of Zn and Y can significantly suppress the formation of the extension twins in the Mg matrix. [9,10] Moreover, there is a general agreement that besides dislocation slip and twinning, the formation of "deformation kinks" in the LPSO phase controls the plastic deformation in these materials.…”

Improvement of Ductility at Room Temperature of Mg-3Al-1Zn Alloy Sheets Processed by Equal Channel Angular Pressing

“…As shown in Fig. 3(d), especially the presence of serrated grain boundaries and small grains (marked as blue arrows) reveal the activation of dynamic recrystallization (Victoria et al, 2013). The mechanism is understood as the result of the continuous production and absorption of dislocation in low angle grain boundaries and the progressive transformation to high angle grain boundaries, i.e.…”

The microstructure, texture and mechanical properties of extruded Mg–5.3Zn–0.2Ca–0.5Ce (wt%) alloy

“…It was reported that calcium-containing particles in AZ31-Ca alloy reduced grain boundary mobility, contributing to the weaker texture [38]. A weaker basal texture was also observed in the as-extruded AZ31 alloy with fine and well distributed Mg 17 Al 12 precipitates around grain boundaries [39]. Therefore, the fine dynamic precipitates Ca 2 Mg 6 Zn 3 at the grain boundaries (Fig.…”