Synthesis, microstructural characterization and microhardness of AlCoNi-SiC composite prepared by mechanical alloying

Abstract

Equiatomic AlCoNi alloy matrix were reinforced by the dispersion of SiC nanoparticles (SiCnp) using the mechanical alloying process. The metallic powders were milled for 10, 20 and 30 h and sintered at 1200 °C under vacuum. Through particle size distribution, X-ray diffraction and scanning electron microscopy investigations, the mechanically alloyed powders for 10 h were selected to be reinforced with SiCnp (2.5, 5 and 10 wt.%). The microstructural features, and improvement in microhardness and porosity of sintered AlCoNi-SiC composites were investigated as a function of SiCnp content. Microhardness Vickers test showed that the enhanced microhardness of the AlCoNi-SiCnp composite could be attributed to the decrease of porosity in comparison to the AlCoNi alloy.