Effect of Particle Size on the Debinding of PIM Parts

摘要

It has been generally accepted that the debinding rate of powder injection molded (PIM) parts can be improved when coarse powders are used due to the larger pore size present in the compact. But, little experimental evidence has been reported. This study compares the solvent and thermal debinding rates of PIM compacts prepared from small and large particles. The weight losses during solvent and thermal debinding on specimens that are prepared from classified powders show that the particle size has little effect. Although the mercury porosimeter shows that larger pore channels are present in coarse powder compacts, their debinding rates are not enhanced. It is suggest that the solvent debinding rate is controlled by the diffusion of the soluble binder in the solvent and the amount of the binder/particle interface area. In the case of the thermal debinding, the decomposition rate of the backbone binder is the rate-controlling step.