Effect of particle size distribution and mixing homogeneity on microstructure and strength of alumina/copper composites

The powder mixtures of Al₂O₃/CuO with a variation in particle size distribution and mixing homogeneity were prepared using different milling process. The mixing homogeneity was quantitatively determined by the coefficient of variation. Homogeneous microstructure and a high fracture strength of the hot-pressed Al₂O₃/Cu composites could be achieved using the powder mixture with narrow size distribution and high mixing homogeneity. The relationship between mixing homogeneity and properties was discussed based on the role of unevenly dispersed second phase for the matrix grain growth andfor the local variation of mechanical characteristics.