Micro-powder injection molding

Micro-system technology and related products will be used more widely in the new millennium. For their successful applications in various fields, e.g. in fluidic, medical, optical and telecommunications, economical mass production of the micro-components will be of great importance. Micro-powder injection molding (μPIM) reported in this work is being developed for possible mass production of metallic or ceramic micro-components. In the initial findings presented here, μPIM was processed using silicon mold inserts with square or round cavities in dimensions of 100 μm, with an aspect ratio of 2.5. Alumina, PZT and 316 L stainless steel powders were tested with different binder systems such as PVA + H₂O, EVA + PW and PAN250 + EVA + HDPE. Results show that all the powders can be used for the molding of micro-components: the finer the powder, the better is the surface finish. PVA + H₂O binder system can be used for room-temperature molding, but with difficulties during molding and de-molding. Micro-components were successfully molded with EVA + PW binder and PZT powders. However, the green parts slumped during thermal de-binding. 316 L stainless steel micro-components were successfully molded, de-bound and sintered using PAN250 + EVA + HDPE binder system.