Characterization of Ternary Mg-Sn-Mn Alloys

Abstract

Ternary Mg-2Sn-Mn (0.5, 1, 2, and 2.5 wt% Mn) alloys were prepared under vacuum/argon atmosphere controlled furnace to investigate their microstructural and mechanical properties as a potential biodegradable implant material. As-cast alloys were heat treated at 550 degrees C for 24 h and then at 300 degrees C for 16 h. The alloys were characterized as-cast and after the heat treatment by optical microscopy, scanning electron microscopy, X-ray diffraction, and microhardness measurement. Mg phase is evident for both as-cast and heat-treated alloys while Mg2Sn intermetallic phase is detected in all heat treated alloys except Mg-2Sn-0.5Mn. The dendritic microstructure changed to a microstructure with equiaxed grains after the heat treatment. The increase of Mn in ternary Mg-2Sn-Mn alloys resulted in a microstructure composed of smaller grains. Moreover, microhardness of ternary alloys slightly increased with the addition of Mn.