Replication and characterization of 316L stainless steel micro-mixer by micro powder injection molding

A 316L stainless steel feedstock suitable for micro powder injection molding was discussed. The homogeneity, thermal and rheological properties of the 316L stainless steel feedstock were characterized by means of SEM, TGA, DSC and capillary rheometer. The 316L stainless steel powder was uniformly distributed within the binder. The 316L stainless steel micro-mixer was well replicated by micro powder injection molding. The molded, debound and sintered micro-mixers had good shape retention, without visible defects, such as warpage, incomplete filling, crack, etc. The dimensional change and surface roughness of the micro-mixer were investigated. The dimensional shrinkage of the micro-mixer took place mainly in the sintering step, whilst the dimensional change was not noticeable in the debinding step. The surface topography of the silicon mold insert was well replicated in the stainless steel micro-mixer. The surface roughness of molded, debound and sintered micro-mixer increased with consecutive processing steps. After sintering, the relative density of the micro-sized structure was 96.56% and there was excessive grain growth.