Effects of hot-compression deformation conditions on microstructures and mechanical properties of pure magnesium

Abstract

Effects of testing temperature and strain rate during hot-compression deformation on the post-deformed microstructures and mechanical properties were investigated for pure magnesium with different initial grain sizes. The grain size after the compression deformation became finer in proportion to the finer initial grain size and the lower testing temperature. On the other hand, little grain refinement was observed after the compression at the high testing temperature (673 K), which was different from that of the Mg-Al (AZ31) alloy. A strong basal texture was formed after the compression at the high testing temperature (673 K) as compared to AZ31 alloy. The coarser grain size, which induced the increase in the generation of tensile twinning, was attributed to the formation of the strong basal texture. As a result of the tensile tests at room temperature for the specimens after compression, the specimens with the strong basal texture showed a higher 0.2% proof stress than the others, because the increase in basal texture intensity induced the increase in friction stress. The specimens with the finer grain size exhibited enhanced ductility. However, at the low testing temperature (423K), the ductility was deteriorated due to the accumulation of strain.