Effect of backbone polymer on properties of 316L stainless steel MIM compact

This study compares the effects of three backbone polymers, LDPE, HDPE and LDPE/HDPE, on the dimensions and mechanical properties of 316L stainless steel MIM compact. MIM parts of optimal quality can be produced using properly formulated binders. A spiral flow test is performed firstly to elucidate the flow behaviors of MIM feedstocks. Secondly, the injection molding of tensile bars is tested to examine the dimensional stability and the mechanical strength of sintered parts against variation in the binder formula. Among the three backbone polymers considered herein, HDPE performs best in terms of both the stability of flow and the MIM compact quality; LDPE performs the worst. HDPE has significantly better length, width, density, and hardness by up to 24%, 27%, 30%, and 64%, respectively. In summary, this work has demonstrated that a backbone polymer strongly affects the dimensions and the mechanical properties of the sintered part. The proper selection of a backbone polymer, such as HDPE, is required to increase the dimensional accuracy and quality of 316L sintered parts.