Optimization and characterization of Stainless Steel Injection Molding Feedstock for Biomedical application

A systematic considerate of thermoplastic polymer in the wax-based binder is necessary for ensuring the dimensions and mechanical properties of 316L stainless steel metal injection molding parts. Metal injection molding (MIM) is considered as a novel technology for producing metal parts with complex geometry. The present work is focused on producing a homogeneous SS 316L feedstock for MIM process by optimizing chemical properties of polymeric and surfactant material. A horizontal mixing machine of capacity 4500 cc is used and Taguchi technique has been used for optimizing the process parameters to produce a homogeneous feedstock of SS 316L. Homogeneity of the feedstock was evaluated by DSC and TGA test. The results reveal the injection molding temperature should be set above 138 °C in order to improve the rheological properties of feedstock and decrease the degradation of the binder, and the mold temperature should be set below 60 °C. Backbone polymer in the binder start degrading at 360 °C until 550 °C, which indicates that in the thermal de-binding stage, the temperature should exceed 550 °C.

Keywords:

Metal Injection molding , feedstock , 316L wax-based binder , rheological properties