Microstructure and hardness characteristics of Al₂O₃-B₄C particle-reinforced Cu matrix composites

Copper is widely used in industrial applications because of its high electrical and thermal conductivity, easiness of processing and good corrosion resistance. However, copper also has some distinct limitations such as low hardness, low tensile yield strength and poor creep resistance. In this report copper matrix was reinforced with ceramics like Al₂O₃ and B₄C particles using powder metallurgy (PM) method and its microstructure was examined with SEM and EDS. The microstructure has revealed an uniform distribution of particles in the matrix and a good interface bonding between B₄C particles and the matrix. However the dispersion of Al₂O₃ particles, of larger sizes, has led to some porosity and inter-particle contacts in the composites. Therefore, hardness of B₄C particle-reinforced composites is significantly higher than that of Al₂O₃ particle-reinforced composites.