Structural, wear and thermal behaviour of Cu-Al_2O_3-graphite hybrid metal matrix composites

摘要

The aim of the present study is to investigate the structural, wear and thermal behaviour of Cu-Al2O3-graphite hybrid metal matrix composites. Copper matrix composites with Al2O3-graphite reinforcement (0.5-0.5, 1.0-1.0, 1.5-1.5 and 2.0-2.0 wt%) were prepared by stir casting process. Phase, microstructure, density, hardness, wear, compressive strength and specific heat of prepared samples have been investigated. X-ray diffraction revealed that there is no intermediate phase formation between matrix and reinforcement phase as a result of interfacial bonding between them. Microstructure study shows the uniform distribution of Al2O3-graphite particles in the Cu-matrix. Density and hardness were found to decrease with increase in reinforcements percentage whereas the compressive strength was found to increase as the amount of reinforcements was increased. Composite containing 2.0 wt% reinforcements showed the maximum resistance to wear. Specific heat was found to increase with addition of reinforcements; however, this increase was very marginal. Structural, wear and thermal properties of these Cu matrix-based hybrid metal matrix composites were found to be dependent on the reinforcements concentration. It is expected that the present composite will be useful for heat exchanger and heat sink applications.