Microstructure and mechanical properties of extruded Mg-8Gd-2Y-1Nd-0.3Zn-0.6Zr alloy

The microstructure and mechanical properties of extruded Mg-8Gd-2Y-1Nd-0.3Zn-0.6Zr alloy rods were investigated. The as-extruded alloy exhibits a weak basal texture that the {0 0 01} basal planes in most grains are distributed parallel to the extrusion direction. The strength of the peak-aged alloy is greatly improved due to the fine beta' precipitates. Tension-compression asymmetry is observed in both the as-extruded and peak-aged alloys. The asymmetry at room temperature is connected with the texture which induces large difference in twinning generation between tension and compression. While increasing the test temperatures, the activation of twinning is suppressed, but the mechanical asymmetry still exists. For the as-extruded alloy it is related to the presence of dynamic strain ageing or dynamic precipitation during deformation; and for the peak-aged alloy it is associated with the beta' precipitates. (C) 2011 Elsevier B.V. All rights reserved.