Secondaries for metal injection molding (MIM)

Abstract The classical flow sheet for metal injection molding usually ends with the sintering process. After final inspection and packing, parts are ready for shipment to the customers. The metal injection molding process is considered to be a netshape technique; thus, any additional process steps would lead to increased production cost and therefore should be avoided. The past decade MIM companies have learned that this kind of thinking is old fashioned. Secondary operations can be used to improve the competitiveness of the MIM process. They offer the possibility to: • improve dimensional tolerances • enhance mechanical properties • improve appearance and surface properties • reduce tooling cost and widen applications of the MIM process This chapter describes several secondary operations such as mechanical deformation, machining, heat treatment, surface treatments, and green machining. Examples from actual MIM parts are used to demonstrate that combinations of secondary treatments can be used to improve competitiveness compared to other production techniques. Furthermore, with techniques such as green machining in combination with other secondary operations, it is possible to reduce manufacturing cost and development time, especially for small order volumes provides. An outlook for further developments, such as advanced furnace systems with integrated hardening, brazing, and welding, is given at the end of this chapter.