Abstract

Metal matrix composites, containing Al (4 wt.% Cu) as the matrix material and SiC particles as the reinforcement, were produced by hot pressing. SiC(p) content of the composites were in 10 – 50 vol.% range. Appropriate amounts of Al, Cu and SiC powder were dry mixed and pressed at 25MPa at 525 and 550^oC. Obtained composites were subjected to density and hardness measurements, 3 point bending tests and optical microscope investigations. Hardness was seen to increase continuously with the increase in the amount of SiC(p) from 54HB10 (unreinforced matrix) to 148HB10 (50 vol.% SiC). On the other hand, bending strength values of the composites first showed an increase up to 20 vol.% SiC and then decreased. Strain values decreased considerably, with the addition of SiC into the unreinforced matrix and the composites containing 40 and 50 vol.% SiC did not show plastic deformation before fracture. Yield strength and elastic moduli of the composites increased with the increase in the SiC amount. It was seen that the properties of Al%4Cu-SiC(p) composites, such as strength and hardness, can be adjusted by varying their SiC contents.