Microstructural, Mechanical Characterization, and Fractography of AZ31/SiC Reinforced Composites by Stir Casting Method

The present work aims to develop an AZ31D magnesium alloy-based composite with SiC reinforcement at 1,2,3 and 4 wt.% using the stir casting route. The micro-structural changes of AZ31D/SiC composites were studied using SEM with energy dispersive spectrometry (EDS) and electron backscattered diffraction (EBSD). The addition of SiC reinforcement notably reduces the grain size of AZ31D Mg matrix. The SiC addition was seen significant change on the microstructure of AZ31D composites which induced improved mechanical properties. The AZ31D composite with 4% SiC reinforcement shows the highest compressive strength of 380.20 MPa. The hardness of AZ31D composite improved to 29% by the addition of 4% of SiC particles. The fractured tensile specimen surfaces of alloy and composites were studied, including fracture types, fracture mechanisms, and reinforcements on the fracture of AZ31D Mg composites.The homogeneous dispersion of refined SiC particles and effective load transfer between the reinforcement and matrix alloy appears to be responsible for the improved properties of AZ31D composite.

Automated summary

The study showed that adding SiC reinforcement can significantly reduce the grain size of AZ31D magnesium alloy matrix, improving its mechanical properties. The AZ31D composite with 4% SiC reinforcement exhibited the highest compressive strength and hardness. The research found that the homogeneous dispersion of SiC particles and effective load transfer play a key role in enhancing the properties of AZ31D composite.