Effect of Aging Treatment on the Mechanical Properties of 45 vol.% SiC_p/6061Al Composite

The effect of aging treatment on the mechanical properties of 45 vol.% SiC_p/6061Al composite fabricated by hot isostatic pressing has been investigated. The results indicate that the hardness and strength of the composite can be strongly improved after solid-solution and aging treatment, with the observations of the accelerated aging kinetic and the double-peak phenomenon. The double-peak phenomenon observed in the 190°C-aged composite is attributed to the substantial amount of G.P. zones and the remarkable precipitation of the β″ and β′ phases, respectively. At 170°C and 180°C, the hardness of the first peak-aged composites were about 216.5 HBW and 217.7 HBW, respectively, and the subsequent fluctuation in hardness was because of the progressive precipitation of the β″ phase and subsequent β′ phase. The maximum yield strength and bending strength were achieved in the composite aged at 170°C for 9 h, being about 688.2 MPa and 798.2 MPa, respectively, with the corresponding increments being about 110.9% and 37% in comparison to that of the as-fabricated composite.