Mechanical Properties of Some Silicon Carbide Reinforced Aluminum Composites

Abstract

The mechanical properties of several particulate and continuous fiber silicon carbide reinforced aluminum composites were examined. The tensile strength of a 47 % silicon carbide fiber unidirectionally reinforced aluminum composite was 1,273 and 76 MPa par allel and normal to the fiber direction, respectively. The tensile strength of [0°/90°]_4s and [0°₂/90°/0°]_s composites were 629 and 864 MPa, respectively. The tensile properties of a 30% silicon carbide particulate reinforced aluminum were found to depend on the chemistry of the metal matrix. The endurance limits of the fiber and the particulate rein forced aluminum were at the most 55 % and 33% of the respective tensile strengths. The fracture toughness of the fiber reinforced composite varied with specimen width, while that of the particulate reinforced composite was 21-29 MPa √_m. The fatigue crack growth rate in the latter composite decreased with material thickness. There were indications that the fatigue crack growth rate in the silicon carbide particulate reinforced aluminum may be independent of variations in the chemistry of the metal matrix.