Improving single pass reduction during cold rolling by controlling initial texture of AZ31 magnesium alloy sheet

The AZ31 magnesium alloy sheets obtained by multi-pass hot rolling were applied to cold rolling and the maximum single pass cold rolling reduction prior to failure of AZ31 magnesium alloy was enhanced to 41%. Larger single pass rolling reduction led to weaker texture during the multi-pass hot rolling procedure. The sheet obtained showed weak basal texture, while the value was only 1/3-1/2 that of general as-rolled AZ31 Mg alloy sheets. It was beneficial for the enhancement of further cold rolling formability despite of the coarser grain size. The deformation mechanism for the formation of texture in AZ31 magnesium alloy sheet was also analyzed in detail.

Effects of processing route on texture and mechanical properties of WZ62 alloy

Mg-6.6%Y-2.3%Zn （WZ62, mass fraction） magnesium alloys were fabricated by equal-channel-angular-extrusion （ECAE）, and ECAE followed by forging processing, respectively. The ＂necklace＂ structure that is composed of fine recrystallized and coarse initial grains was found. The process of dynamic recrystallization （DRX） is associated with the strain localization. With increasing ECAE passes, the tensile test results reveal that both the strength and elongation are enhanced. A typical non-basal texture component in the （0002） pole figures with tilted peaks at about 45° was observed. After ECAE followed by forging processing, the strength increases greatly with sacrificed ductility. That is attributed to the change in the texture： the majority of basal planes is rotated to be normal to the normal direction. The non-basal texture induced by ECAE is modified by the secondary forging processing.

Dynamic microstructure evolution and mechanical properties of dilute Mg-Al-Ca-Mn alloy during hot rolling

The dynamic microstructure and texture of dilute Mg-0.50Al-0.71Ca-0.33Mn(wt.%) during hot rolling at two slab temperatures were investigated by electron backscattered diffraction(EBSD) and high resolution transmission electron microscopy(HRTEM). The results show that the development of the rolling microstructures is to first form {10–12} extension twins in the original grains, thereby forming the extension-twinned regions, and then to further form {10–11}-{10–12} double twins and kinks in the extension-twinned regions, and finally to form continuous dynamic recrystallized(continuous DRXed)grains in the double twins and the cross parts of the shear-deformed coarse extension-twinned regions.These extension twins, double twins and kinks show a decisive effect on the formation of rolling texture.The number of {10–11}-{10–12} double twins and resultant the continuous DRX process are strongly affected by the rolling slab temperature and the reduction thickness per pass. By optimizing the rolling conditions, texture and microstructures of the multi-pass rolled Mg-Al-Ca-Mn alloy sheets are successfully modified. Although the total alloy content is only 1.5 wt.%, these Mg-Al-Ca-Mn alloy sheets show much higher strength than the commercial Mg-3Al-1 Zn(wt.%)(AZ31B) sheet.