Revealing grain structure development and texture evolution during elastic stress-assist aging of Mg–Zn alloys

Abstract

The evolution of grain structure and corresponding texture development of Mg alloys under the assist of multiple physical fields are interesting and meaningful topics, and are investigated in this paper in detail. The results show that the texture development of stress free (SF) aged alloy exhibits a remarkable difference in type and intensity to those of 100 MPa tensile stress (100-TS) and 100 MPa compressive stress (100-CS) aged alloys at 160 °C. In the early stage of SF aging, preferential growth of<11-20>//ED grains give rise to the enhancement of<11-20>//ED fiber component. The increased pinning force caused by considerable precipitates at high energy boundaries reduce the boundary mobility, and therefore lead to a weak basal texture at the end of aging. Heavily activated prismatic<a> dislocations under the action of 100-TS aging facilitate the precipitation of secondary phases at grain boundaries and lattice rotation induced continuous static recrystallization (CSRX) in the early stage of aging, which contributes to a weak basal texture and the formation of non-fiber texture. Upon further aging, the preferential growth of pre-existing<10-10>//ED grains and recrystallized grains formed by CSRX contribute the enhancement of<10-10>//ED basal fiber component. In the case of 100-CS aging, the slight growth of<11-20> grains and lattice rotation caused by prismatic<a> dislocations lead to the enhancement of<11-20>//ED texture component in the early stage of aging. After long-time compressive stress aging, preferential growth of<10-10>//ED grains gives rise to the formation of<10-10>-<11-20> double fiber components.