Metal Injection Molding
Metal injection molding (MIM) offers a manufacturing capability for producing complex shapes in large quantities. The process utilizes fine metal powders (typically less than 20 micrometers) that are custom formulated with a binder (various thermoplastics, waxes, and other materials) into a feedstock. The feedstock is fed into a cavity (or multiple cavities) of a conventional injection molding machine. After the "green" component is removed, most of the binder is extracted by thermal or solvent processing, and the rest is removed as the component is sintered (solid-state diffused) in a controlled-atmosphere furnace. The MIM process is very similar to plastic injection molding and high-pressure die casting, and it can produce much the same shapes and configuration features.
The advantages of the metal injection molding process lie in its capability to produce mechanical properties nearly equivalent to wrought materials, while being a net-shape process technology with good dimensional tolerance control. Metal injection molded parts offer a nearly unlimited shape and geometric-feature capability, with high-production rates possible through the use of multi-cavity tooling.
Metal Injection Molding Association
The is a wonderful resource to learn more about this innovative technology. MIMA also hosts an annual conference on injection molding of metals, ceramics and carbides. Information can be found on their website, or on the Events portion of this website.