Effects of extrusion temperature on microstructure, texture and mechanical properties of Mg–Bi magnesium alloy

Abstract

The effects of extrusion temperature on the microstructure, texture and mechanical properties of a Mg–5 wt%Bi alloy prepared through extrusion were systematically investigated. With the increase of extrusion temperature from 573 to 723 K, the average grain size of the extruded bars gradually increased from 10.2 to 17.4 μm, and the amount of Mg3Bi2 precipitates that dynamically formed during the extrusion apparently decreased while their size remarkably increased. Moreover, the basal texture intensity of the extruded bars increased with increasing the extrusion temperature. This may be attributed to the combined effect of the decreased amount of Mg3Bi2 precipitates, enhanced activity of the prismatic slip and growth of dynamically recrystallized grains. With increasing extrusion temperature, yield strength first decreased but then increased, whereas elongation to fracture first increased but then decreased.