Effects of Ball Milling Time and Alumina Content on Microstructure and Properties of Alumina Dispersion Reinforced Copper Based Composites

Using high energy ball milling method through changing the content (mass fraction) of alumina and milling time to sinter alumina particle dispersion reinforced copper matrix composites with different Al2O3 contents. The effects of alumina content and ball milling time on the microstructure and properties of the sintered body were studied by microstructure observation, relative density, conductivity and hardness test. The results show that when the milling speed was 270 r·min-1 and with prolonging the milling time, the grains refined and lattice distortion increased, the grains changed from laminar shape to spherical shape gradually. And the relative density of the sintered body increased first and then decreased, the conductivity and hardness increased. With the decrease of the content of alumina the relative density raised, the hardness decreased first and then increased. When the Al2O3 content was 1.2wt% the maxinal relative density was 89.4%, and the highest conductivity was 50%IACS.