Effects of dispersion technique and component ratio on densification and microstructure of multi-component Cu-based metal powder in direct laser sintering

A multi-component Cu-based metal powder, which consisted of a mixture of Cu, CuSn, and CuP, was developed for direct metal laser sintering (DMLS). The effects of powder characteristics such as particle shape, particle size and its distribution, and dispersion uniformity on the sintering behavior were studied. It is found that using a homogeneous powder mixture produced by ball mixing coarse and fine powders with a broad particle size distribution could increase the original density of the loose powder and, thus, the densification and microstructural homogeneity of the laser sintered powder. The influence of the binder (CuSn) content on the densification and the resultant microstructures of the laser sintered samples were also investigated. It shows that with increasing the amount of the binder, the microstructure became denser. However, at a high content larger than 50 wt.%, the densification showed a decrease, because of the “balling” effect.