Microstructure, texture and mechanical properties of AZ31 Mg alloy produced by equal channel angular extrusion

AbstractEqual channel angular pressing (ECAP) was carried out on samples machined from extruded AZ31 Mg alloy bars at 200, 250 and 300 °C using routes A and C for up to 8 passes. After one ECAP pass, a preferred orientation with the basal planes inclined at 45° to the ECAP axis is observed. For route A, as more passes are employed, the original fiber texture tends towards a rolling texture. By contrast, for route C, repeating the ECAP steps does not change the texture, which retains the 45° preferential orientation. Using a path with shearing in more directions, such as route C, resulted in the flow curve peak being less sharp (i.e. broader) in subsequent testing than when route A was employed. The strength of the extruded product increases with the ECAP temperature. This appears to be due to the coarser grain size of the 300 °C product and indicates that the effect of grain coarsening is greater than that of texture.