Microstructure, Texture and Mechanical Properties of Al-Mg-Si Alloy Processed by Multiaxial Compression

Abstract

The present work aims to study the effect of multiaxial compression (MAC) on the evolution of microstructure, texture, and mechanical properties of Al-Mg-Si alloy. MAC was successfully performed at room temperature up to three cycles to produce ultrafine-grained microstructure. Processed samples were characterized using electron backscatter diffraction and x-ray diffraction techniques to study the evolution of microstructure and texture. There was a drastic decrease in the grain size from an initial average grain size of ~ 124 to ~ 3 μm after completion of MAC processing. The fraction of high-angle grain boundaries decreased after the first cycle and then increased in subsequent cycles. Pole figure measurement suggested the evolution of brass, copper, and S texture components after completion of three cycles. The effect of evolved microstructure on mechanical properties was evaluated using hardness measurements and uniaxial tensile tests. The average hardness and yield strength value increased from 52 VHN and 90 MPa for the initial condition to 95 VHN and 249 MPa after three cycles of MAC, respectively. Strain-hardening exponent was found to increase continuously with MAC cycles.