Effect of SiC and ZrO₂ Reinforcements on the Microstructure and Mechanical Properties of Al6063 Hybrid Composites

Abstract

The influence of silicon carbide (SiC) and zirconium dioxide (ZrO₂) reinforcements on the microstructure and mechanical properties of stir-cast Al6063 hybrid composites was investigated. Five compositions were fabricated: Al6063 (S0), Al6063/5 wt.% SiC (S1), Al6063/5 wt.% ZrO₂ (S2), Al6063/2.5 wt.% SiC/2.5 wt.% ZrO₂ (S3), and Al6063/5 wt.% SiC/5 wt.% ZrO₂ (S4). Mechanical characterization was carried out through tensile and hardness testing, while reinforcement distribution and microstructural features were examined using SEM–EDX analysis. A significant enhancement in the mechanical performance of Al6063 was observed following the incorporation of ceramic reinforcements. The highest yield strength (124.43 MPa), ultimate tensile strength (186.67 MPa), and hardness (86 HV) were achieved by the S4 composite. The successful dispersion of SiC and ZrO₂ particles with minimal agglomeration was confirmed through SEM-EDX observations. The observed improvements were attributed to effective load transfer, grain refinement, and the restriction of dislocation movement. The results demonstrate that Al6063-SiC-ZrO₂ hybrid composites can be considered promising materials for lightweight structural and engineering applications.