Consolidation and mechanical properties of mechanically alloyed Al-Mg powders

摘要

Nanostractured Al-Mg bulk samples with compositions in the range of 10 - 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al_(90)Mg_(10) and Al_(80)Mg_(20) were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al_(90)Mg_(10) specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al_(60)Mg_(40) powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.