A 6061 Al coating for AZ31 Mg alloy was prepared by multi-pass friction stir welding (FSW) with different travel speeds. The microstructure, mechanical properties of the interfacial region and the corrosion behavior of the coating were investigated systematically. The results indicate that the interfacial intermetallic compounds formed in the stir zone (SZ) consist of mainly Al12Mg17 and Al3Mg2. The intermetallic compounds in the SZ are significantly increased when the travel speed is increased from 30 mm/min to 60 mm/min. Microhardness measurements and results of shear-tensile tests show that the mechanical properties are influenced by the intermetallic compounds formed in the SZ during FSW. Corrosion tests indicate that the 6061 Al coating can significantly improve the corrosion resistance of AZ31 plate. The 6061 Al coating obtained with a travel speed of 30 mm/min has a maximum corrosion potential Ecorr of -0.503 VVSE.

This study investigated the microstructure and thermal conductivity of as-cast and as-extruded binary Mg–Mn alloys. The large grains and fine α-Mn particles contained in the as-cast alloys were observed. After extrusion, the average grain sizes significantly decreased, typical basal fibre texture was generated and high amount of nano particles precipitated from the α-Mg matrix. The thermal conductivity of both as-cast and as-extruded Mg–Mn alloys gradually decreased with the increase in Mn concentration. As-extruded alloys exhibited lower thermal conductivity than as-cast alloys except for the as-extruded alloys containing higher Mn concentrations (>1.2 wt-% Mn). Compared with binary as-extruded Mg–Al and Mg–Zn alloys reported in literatures, thermal conductivity of the as-extruded Mg–Mn alloys was higher when the solute content was greater than 0.5 at.-%.