Deformation control of large sized MIM parts by changing the powder size distribution

Metal Injection Molding (MIM) process is suitable for fabricating small parts in large quantity. In this work, relatively large and complex shaped parts were prepared thorough MIM. In order to decrease the deformation of sintered parts, powders of different sizes were mixed. The effect of powder particle distribution and powder loading on the distortion of complex shaped compacts were investigated and evaluated. As smaller the particle size of mixed powder, tap density of powder were decreased. However, sintered density and shrinkage were increased. Although high powder loading increased the viscosity during the injection molding, decreased the shrinkage of sintered compact. From these results, smaller deformation of the large and complex shaped parts could be realized by using smaller particle size of mixed powder and higher powder loading.