Experimental investigation on the mechanical properties of aluminum-based metal matrix composites by the squeeze casting method

Abstract This work is aimed at improving the mechanical properties of AA7075 by adding TiB 2 reinforcements by using ex situ method. The squeeze casting process was used in the manufacturing of metal matrix composites with varying weight concentrations (1.5, 3, and 4.5%) of TiB 2 particles. The effects of change in the TiB 2 weight % on the tensile strength, hardness, and wear rate of the composite were studied. The distribution of the TiB 2 reinforcements in the matrix was observed during the microstructure examination qualitatively. Experimental results confirmed that the hardness was significantly increased as compared to the base alloy. The increase was about 26% as compared to the as-cast AA7075. Both the yield and ultimate tensile strengths of the AA7075/TiB 2 composite were higher than that of the base alloy. The tensile strength increased to 354 MPa (18% increase as compared to the as-cast alloy). The enhancement of the strength of the composite is due to the addition of TiB 2 reinforcement particles and proper wettability between the matrix and reinforcement material. The fractography analysis revealed the presence of small and shallow dimples, which serve as an indication of the level of ductility that was retained within the composite material, even after the incorporation of TiB 2 particles into the matrix.