Influence of Mixing Different Types of Powder on Microstructure and Sintering Behavior of Compacts

Variations in microstructure and sintering behavior of metal/ceramic powder compacts with mixing ratio are examined by using alumina and stainless steel powder particles. Inhomogenous microstructure of the compacts can be observed as sharp separate peaks on the curve of pore size distribution. Mixture homogeneity of the compacts, which is estimated from the green density, increases with decreasing the volume fraction of strainless steel. Gaining the size of alumina powder also makes the mixture homogeneity large. Isolated stainless steel particles in homogenous microstructure do not bond together even in sintering process and may only inhibit the uniform densification of alumina powder. Although the alumina powder regions in the mixtures shrink locally, pores around the stainless steel particles are not eliminated, and may result in low density of sintered body.