Microstructural, mechanical, and cavitation erosion analysis of stir casted AA6063, doped with SiC and Er ₂ O ₃ particulates

Hybrid composites offer advantages over single composites due to their superior properties and ease of processing. In this research, the mechanical and surface characterization of a hybrid composite based on AA6063 was carried out, reinforced with 5 wt.% Silicon Carbide and varying concentrations of Erbium Oxide at 0, 2, 4, and 6 wt.%, fabricated using the stir casting technique. The composite with 4 wt.% Er ₂ O ₃ exhibited the highest tensile strength of 134 MPa and a maximum hardness of 58 HV, representing improvements of 17.16% and 24.14%, respectively, over the unreinforced alloy. Cavitation erosion resistance also improved significantly, with a mass loss reduction of 74.2%, from 26.29 g (AA6063) to 6.78 g in the optimized composite. These enhancements were attributed to refined microstructure, reduced porosity, and improved reinforcement dispersion, as confirmed through SEM, XRD, and EDAX analyses. Overall, the study underscores the potential of Er ₂ O ₃ -SiC-reinforced AA6063 composites in structural and erosive environments.