Effects of T6 Treatment, Tensile Temperature, and Mass Fraction of SiC on the Mechanical Properties of SiC_p/6061Al Composites

SiCp/6061Al composites have been developed and widely applied in many fields, such as automobile, aerospace, shipping, and so on. Considering heat treatment, service environment, and strength of composites, this paper comprehensively studies the mechanical properties of SiCp/6061Al composites with a large range of SiC mass fractions under T6 treatments and different tensile temperatures. SiCp/6061Al composites were successfully prepared by hot press sintering at various SiC mass fractions (0–30%), and the influences of SiC concentration and T6 treatment on the mechanical properties of composites were characterized via tensile tests at room temperature, 100, and 200 °C. Microstructure and fracture surfaces of composites with various SiC concentrations were further analyzed by optical microscope and SEM. The formula for the biggest critical reinforcement concentration for the saturated distribution of SiC is proposed to reveal the strengthening rule of different SiC concentrations. Results show that the effect of T6 treatment on the mechanical properties of composites is a marked increase in tensile strength and an obvious decrease in elongation. The increase in the SiC mass fraction, except at 30%, is able to bring an increase in tensile strength and a decrease in elongation, and the change of the elongation is insignification in T6-treated specimens. The tensile strength of T6-treated specimens decreases as temperature increases, and the composite has a maximum elongation at 100 °C.