Two-dimensional simulation of mass transport in polymer removal from a powder injection molding compact by thermal debinding

Abstract

Two-dimensional simulation of thermal debinding in powder injection molding based on mass and heat transfer in deformable porous media is proposed. The primary mechanisms of mass transport, i.e., liquid flow, gas flow, vapor diffusion, and convection, as well as the pyrolysis of polymers, and their interactions, are included in the model. The simulated results revealed that polymer removal process is primarily affected by liquid flow, which is mainly dominated by pressure-forced flow rather than capillary-driven flow. A significant phenomenon, enrichment with liquid polymer in the outer surface regions of the compact, is explained.