The effect of particle size,sintering temperature and sintering time on the properties of Al–Al2O3 composites,made by powder metallurgy

Al₂O₃ is a major reinforcement in aluminum-based composites, which have been developing rapidly in recent years. The aim of this paper is to investigate the effect of alumina particle size, sintering temperature and sintering time on the properties of Al–Al₂O₃ composite. The average particle size of alumina were 3, 12 and 48 μm. Sintering temperature and time were in the range of 500–600 °C for 30–90 min. A correlation is established between the microstructure and mechanical properties. The investigated properties include density, hardness, microstructure, yield strength, compressive strength and elongation to fracture. It has been concluded that as the particle size of alumina is reduced, the density is increased followed by a fall in density. In addition, at low particle size, the hardness and yield strength and compressive strength and elongation to fracture were higher, compared to coarse particles size of alumina. The variations in properties of Al–Al₂O₃ composite are dependent on both sintering temperature and time. Prolonged sintering times had an adverse effect on the strength of the composite.