Effect of reinforcement particles and multipass of friction stir processing on microstructure and mechanical properties of aluminium alloy

Abstract

The present study focuses on the successful fabrication of aluminium metal matrix composites (AMMCs) using friction stir processing (FSP) and micro-sized SiC as reinforcement particles (RPs). The microstructure of Al6061-T6/SiC AMMCs in the stir zone was examined using Electron Backscatter Diffraction (EBSD), Energy Dispersive Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). The incorporation of SiC particles and the refinement of grain structure resulted in upgraded mechanical properties of the AMMCs achieved through three FSP passes. These enhancements were concerning from the reduction in grain size and more orderly dispersal of SiC particles. Moreover, the microhardness of the AMMCs enhanced by 41.79%, by augmenting the FSP passes, which can be characterized by the refinement in grain structure, facilitated by the dynamic recrystallization (DRx) mechanism.