Synergistic effect of sintering temperature on microstructure, mechanical properties, and fractography analysis of spark plasma sintered Al-10 %SiC-4 %Kaoline composite

In this study, aluminium composites reinforced with 10 wt% SiC and 4 wt% kaoline were synthesized through the spark plasma sintering (SPS) technique at different sintering temperatures of 560 ⁰C, 580 ⁰C and 600 ⁰C. The influence of the sintering temperatures on the microstructure and mechanical properties was investigated. Results demonstrate that the maximum relative density (RD), hardness, compression strength, and tensile strength of 96 %, 72 Hv, 284 MPa, and 263 MPa respectively for the composite sintered at 580 ⁰C. The agglomerations were identified at 560 ⁰C through SEM analysis due to improper sintering of the SiC reinforcements which deteriorated the strength of the composite. The presence of dimples on the tensile fractured surface at 580 ⁰C confirms the ductile fracture. However, the existence of intergranular cleavages and particle debonding at 560 ⁰C and 600 ⁰C promotes the brittle fracture.