The beneficial effect of AgIn addition on deformation behavior, microstructure and texture in Mg-Al-Zn alloy during single pass warm rolling

摘要

In this study microstructure, texture and deformation behavior of Mg-3Al-1Zn (alloy-1) and Mg-3Al-1Zn-0.5AgIn (alloy-2) were investigated. The alloys were subjected to single pass thickness reductions of 30%, 50% and 60% at 300 ℃ (573 K) followed by annealing at 400 ℃ (673 K). Scanning electron microscopy (SEM), X-ray based macro-texture, transmission electron microscopy (TEM) and electron backscat-ter diffraction analysis (EBSD) were performed to investigate the effect of Agin addition on deformation and annealing behavior. A silver-containing second phase in the form of fine precipitates was observed in alloy-2 during rolling which remained thermally stable during subsequent annealing. An ultrafine microstructure was observed for alloy-2 in comparison to alloy-1 after rolling. EBSD based Schmid factor (SF) analysis revealed a significant contribution of extension twinning, basal slip, pyramidal (c + a) slip and prismatic slip in alloy-2. In contrast, contraction twinning was the predominant deformation mode in alloy-1. The combined activity of larger number of deformation modes resulted in improved formabil-ity, refined microstructure and a weak deformation texture in alloy-2. The improved rolling response was mainly attributed to the combined contribution of multi deformation modes.