Effect of rare earth elements on the microstructure and texture development in magnesium–manganese alloys during extrusion

Abstract

Single additions of the rare earth (RE) elements cerium, yttrium or neodymium have been made to magnesium–manganese alloys in order to investigate their influence on the microstructure and texture formed during indirect extrusion and the resulting mechanical properties. Whereas the binary Mg–Mn alloy M1 exhibits a 〈10.0〉 or 〈10.0〉–〈11.0〉 fibre texture depending on the extrusion rate, the RE-containing alloys exhibit weaker recrystallisation textures and the formation of a new texture component. The preferential growth of grains having 〈11.0〉 parallel to the extrusion direction was hindered in these alloys. For the rare earth elements used in this work it appears that Nd is a much stronger texture modifier compared to Ce or Y in Mg–Mn alloys. The weaker texture leads to increased ductility, lower yield and ultimate stresses, but a decrease in the asymmetric yield behaviour of the extruded bars.