Effect of Cold Deformation on Structure and Properties of Cu-Al_2O_3 Composite Prepared by Simplified Technique
Cu-Al2O3 composites with different oxygen resource coefficients were prepared by a new simplified internal oxidation technique.The microstructure and hardness,electrical conductivity of composites after sintering and deforming were investigated.The results indicate that Cu-Al2O3 composites are prepared successfully by the simplified technique,a mass of fine Al2O3 particles are dispersed in the copper base,the size of Al2O3 particles is about 10~20 nm in diameter,and the spatial distance between particles is about 25～60 nm.The hardness is obviously increased after deforming of 60%,70% and 80%,and the maximum peak value reaches 144 HV.Electrical conductivity increases at the beginning and then decreases with the increasing of deformation.After sintering at 950 ℃ for 4 h,the internal oxidation of compressed Cu-Al alloy powder is completed,and the comprehensive performance is optimum after deforming when the oxygen resource coefficient(k) is 1.20.So it is the optimum oxidant content for internal oxidation under this process.