The effect of reinforcement particle size on the properties of Cu-Al2O3 composites

Abstract

abstractThe main aim of this paper was to investigate the effect of reinforcement particle size on the properties of Cu-Al2O3 composites. The starting materials for obtaining the composites were commercial powders: Cu and Al2O3. Experiments were performed using specimens containing 2.5, 5, 7.5 and 10 % of alumina. The average particle sizes of alumina were 3.5, 22.5, and 65 μm. Before the sintering process, single pressing was performed with a hydraulic press at a compaction pressure of 620 MPa. The obtained sinters were subjected to the compaction process at a pressure of 620 MPa, and then again sintered at 900 °C for 60 minutes. The sintering process was carried out for 60 minutes at a temperature of 900 °C. The sintered compacts were subjected to the following tests: measurement of density, hardness and electrical conductivity. Observations of the microstructure on metallographic specimens made from the sintered samples were also performed using a scanning electron microscope (SEM). The density of all the composites increased when the particle size of alumina was reduced. Higher hardness were observed in samples containing finer Al2O3 particles. The electrical conductivity of the fabricated composites increased with the reduction of the alumina particle size.