Effect of silicon carbide particles on properties of Al/Sip + SiCp

This work focuses on the fabrication of hybrid-particle-reinforced aluminum composites (Al/Sip + SiCp) via gelcasting and vacuum pressure infiltration. Composites with high volume fractions hybrid particles were fabricated. The distribution of silicon particles (Sip) and silicon carbide particles (SiCp) in the composite is uniform as verified through optical microscope examination. Thermal properties of Al/Sip + SiCp were also measured. Compared with Al/Sip with the same volume fraction reinforcement, Al/Sip + SiCp has higher thermal conductivity (TC) and flexural strength, but lower thermal expansion coefficient (CTE). Detailed scanning electron microscope (SEM) examination of the fracture surfaces and optical observation of microstructure beneath the fracture surfaces of both composites were made to investigate the fracture processes and strengthening mechanism for the composite.