Evaluation on the homogeneity of feedstock for micro size parts produced by MIM

Producing the micro size parts by Metal Injection Molding (MIM) needs more sophisticated technique than the conventional injection molding. Especially, inhomogeneous state of the feedstock will strongly influence on the quality of the final products. In order to evaluate the mixing and palletizing conditions of the feedstock, statistical variations of density and binder contents in individual pellet were investigated by the weight measurement. These variations were discussed with coefficient of variation. The micro dumbbell specimens were fabricated using the feedstock, and the density and strength were investigated. Moreover, in order to improve the feedstock properties, re-pelletizing was performed. It was found that the homogeneity of the pellet was one of the important factors for quality of the micro size parts produced by MIM.