Structural and Mechanical Properties of Al/B4C Composites Fabricated by Wet Attrition Milling and Hot Extrusion

In this study, Al matrix composites reinforced by 7.5 and 15 vol.% B4C particles and also monolithic Al (Al without the B4C particles) were produced by wet attrition milling and subsequent hot forward extrusion processes. The microstructure of the composites, evaluated by scanning electron microscopy (SEM), showed that the B4C particles were properly distributed in the Al matrix. Mechanical properties of the Al/B4C composites and monolithic Al were investigated by tensile, wear and hardness tests. The results revealed that with increasing content of B4C particles, the tensile strength and microhardness of composites increased but the elongation decreased. In addition, the tensile strength and microhardness of composite samples were higher than those of monolithic Al. The density measurements revealed that the density of composites decreased with increasing content of the B4C particles.