Experimental Investigation on the Anisotropy of Wrought Magnesium Alloy by Complete Evolution of Equivalent Plastic Work Contours in “σxx-σyy” Space

Focusing on non-proportional loading condition during forming process of HCP metals, the equivalent plastic work contours of AZ31 Mg alloy are investigated experimentally under combined biaxial test. Strong anisotropy including initial strength differential effect and subsequent distortional hardening are detected. The underlying deformation mechanisms are discussed based on microstructure observation. It is found that the specimen undergoes the main plastic deformation and high stress state along the direction with larger strain ratio. Under the combined load of tension and compression, the c-axis change of the grains in the sample is mainly the deflection along the normal direction, which results in the deformation dominated mainly by dislocation slip. The difference in deformation mechanism leads to different evolution of equivalent plastic work contour in four quadrants.