THERMAL AND MECHANICAL COUPLING IN GRANULAR MODELING FOR METAL INJECTION-MOLDING

Metal injection molding (MIM) employs viscous thermoplastic polymer ma terials (binders) with metallic powders to improve flowability and for mability. It is essential to be able to describe the behavior of such mixed materials, for this purpose a new granular model being proposed to deal with the powder characteristics and mechanics. The composite e lement is designed to consider both elasticity and viscosity for powde r particles and binders. A thermal and mechanical coupling effect is i ntroduced directly to describe the cooling process. Numerical results demonstrate the effectiveness and validity of the presently-developed granular modeling in dealing with the various phenomena appearing in t he MIM process.