Optimization of spark plasma sintered parameters of Al–SiC–kaolin hybrid composite using Taguchi–grey relational analysis

Abstract

This study investigates the effects of sintering parameters on the mechanical properties and microstructure of spark plasma sintered aluminium hybrid composites reinforced with 10 wt% SiC and 4 wt% kaolin. Using Taguchi–grey relational analysis (TGRA), the sintering temperature, compaction time, and compaction pressure were optimized based on their influence on density, ultimate tensile strength (UTS), and compression strength. Experiments were designed using an L₉ orthogonal array, and ANOVA analysis was performed to determine the percentage contribution of each parameter. The optimal sintering conditions were found to be at a temperature of 570°C, a compaction time of 5 min, and a pressure of 20 MPa, resulting in a maximum density of 2.72 g/cc, UTS of 313 MPa, and compression strength of 379 MPa. Microstructural analysis through SEM revealed a homogeneous distribution of reinforcements at the optimal conditions, while the presence of Al₂Cu intermetallic compounds was detected near the grain boundaries at non-optimal conditions. These results confirm that optimized sintering parameters significantly enhance the mechanical properties of the composite.