Effect of severe plastic deformation on thixomolded~R AZ91D Mg alloy

摘要

Severe plastic deformation is imparted to the thixomolded AZ91D alloy plate by pure compression at 120°C and Alternate Biaxial Reverse Corrugation (ABRC) at 300°C followed by flattening at 280°C. Twinning dominates the deformation process within "primary" solid particles of thixomolded materials at lower elevated temperature pure compression, but not in the fine grain eutectic structure. Extensive twinning occurs with increasing strain and assists the subdivision of initial coarse "primary" a grain, but the angle between the twinning plane and compression axis increases with increasing strain, as more slip occurs to accommodate plastic flow. ABRC process produces ultra-fine grained AZ91D alloy with greater efficiency of grain refinement and more homogeneous grain structure. Mechanical properties are also improved by ABRC deformation process.