Achieving Superplasticity of Ultrafine-Grained Rod-Like AZ61 Alloy Using High-Pressure Sliding

Abstract

Recent study demonstrated that processing through High-Pressure Sliding (HPS) is effective for grain refinement of a rod-like A2024 aluminum alloy. In this study, the HPS processing was applied to an AZ61 magnesium alloy. To achieve homogeneous grain refinement throughout the cross section of the rods, the samples were rotated around the longitudinal axis of the rod every after HPS processing. Microstructural observations revealed that the grain size was refined to 450 nm. Tensile tests showed that the samples exhibited excellent superplasticity with a maximum elongation of 1140% at a testing temperature of 473 K and at an initial strain rate of 1.0×10−3 s−1, giving a strain rate sensitivity of 0.4.