Effect of the particle size on the mechanical properties of 60 vol.% CiP_p reinforced Al matrix composites

The effect of the reinforcing particle size on the mechanical properties of 60 vol.% SiC reinforced aluminium matrix composites produced by the pressure infiltration technique was examined by compression, impact and wear tests. The compression strength and the impact resistance decreased with increasing reinforcing particle size. The composites exhibited different abrasion behaviour depending on the size of abrasive Al₂O₃ grains. On fine abrasive Al₂O₃ grains (85 μm), the abrasion resistance increased with increasing reinforcing SiC particle size. The contrary result was obtained on coarse abrasive Al₂O₃ grains (250 μm). The wear tests conducted on M2 quality tool steel revealed that reinforcing of aluminium with coarse SiC particles has a very beneficial effect on the wear resistance with respect to fine reinforcing SiC particles.