Effect of SiC Content and T6 Heat Treatment on Bending Properties of Al6061/SiCp Composites: Homogenous and Graded

Due to its high specific strength and low coefficient of thermal expansion, Al/SiCp homogenous composites (HC) have become a widely used material in automobile and other fields. The application of components with different internal and external material performance requirements such as automobile pistons and brake disks has promoted the development of functionally graded materials (FGM). Therefore, Al/SiCp composites are expected to be applied on a large scale. Al6061/SiCP composites were prepared by vacuum hot-pressed sintering whose microstructure observation is carried out and mechanical properties are tested. The hardness of the Al/SiC HC increases gradually as the SiC content increases from 0 to 30 wt.%. The hardness values of the T6-treated Al6061/SiCp HC with SiC mass fractions of 0, 5, 10, 15, 20, 25, and 30% are 97, 101, 104, 111, 113, 118, and 125HV, respectively, and it is a maximum increase of 117.48% compared with HC without T6 treatment. The flexural strength increases and the deflection decreases with the increase of SiC content, and T6 heat treatment also improves the flexural strength of all composites with about 30% increase over that without T6 heat treatment. When the load was applied from the layer with high SiC content of FGM whose interlayer difference is 5%, the strength and deflection were superior to those of the HC.