Effect of Friction Stir Processing on Superplasticity of AZ31 Magnesium Alloy

Abstract

Friction stir processing (FSP), an adaptation of the solid-state joining process friction newlinestir welding (FSW), is a widely recognized severe plastic deformation (SPD) technique newlinewhich induces complicated state of stresses and strains in the metallic materials. This newlineleads to grain refinement and microstructural homogenisation which helps in enhancing newlinethe formability and other mechanical properties of many non-ferrous alloys. Fine grains newlinein the microstructure is one of the major pre-requisites to attain superplasticity. newlineSuperplasticity is the capability of a polycrystalline material to get uniformly elongated newlinemore than 200% by plastic deformation before its failure. This feature is beneficial in newlineencapturing several design details in a single complex-structured component. Out of newlineMg-Al-Zn (AZ) series of wrought Mg alloys, AZ31 is a largely recommended alloy newlinehaving an advantageous blend of low density and moderate strength. Developing newlinesuperplasticity in AZ31 Mg alloys has a promising appeal in broadening the limited newlinespectrum of its applications in the automotive and aerospace sectors. Multi-pass FSP is newlineanother aspect to develop excellent microstructural homogeneity and consequential newlinesuperplasticity in Mg alloys. newline