EFFECTS OF CATEGORY AND CONTENT OF REINFORCEMENTS ONMECHANICAL PROPERTIES OF METAL MATRIX COMPOSITES

Some aluminum matrix composites, reinforced by alumina and silicon carbide particles, were fabricated by P/M method, and the normal mechanical properties were measured. It is shown that the elastic modulus increases with volume fraction of ceramic particles, though the fracture strain decreases. SiC_P/2024 system has the highest strength and best reinforcing efficiency, with the increase of particle volume fraction to 25%. SiC_P/7075 system has lower strength than that of the controlled alloy. SiC_P/pureAl system shows higher reinforcing efficiency in spite of the lower absolute strength. Al₂O_3P/2024 system exhibits a character of first rise and then drop in strength. It is considered that these differences may depend on the strength levels of reinforcements and the matrices and the deforming characteristics. The better matrices should have higher strength as well as higher workhardening rate.