Microstructure, mechanical behaviour, and thermal shock effects of five layered thick Al/SiC functionally graded material fabricated by spark plasma sintering technique

Functionally graded materials (FGMs) with specific material compositional variations ranging from metal-rich to ceramic-rich provide plenty of advantages in aerospace, defence, and automotive applications. In this study, thick Al/SiC FGM was fabricated using the spark plasma sintering technique to investigate the microstructure, mechanical, and thermal shock behaviour. The fabricated thick FGM consisted of five layers with varying proportions of aluminium and silicon carbide, calculated using a power law formulation. The microstructural analysis confirmed the linear increment of the SiC particles across the thickness direction. The mechanical test findings revealed a tensile strength of 139 MPa and a compressive strength of 242 MPa, while micro-hardness and free vibration analysis was carried out further. The thermal shock test micrographs indicated the interfacial fractures and the existence of thick oxide layer, which also confirms through EDS mapping. These research findings enhance the understanding the mechanical and thermal loading behaviour of the Al/SiC FGM’s, which will potentially contributing the usage of FGMs in the advanced engineering applications.