| | Metal Injection Molding Is Shaping Up As A Popular Alternative Metal Injection Molding (MIM) is here to stay. Commercially available for only about 20 years, metal injection molding is growing increasingly popular with a gamut of industries — particularly medical device, telecommunications, electronics and automotive parts manufacturers — becoming a viable and cost-effective alternative to other types of metal processes, such as machining and casting. The driving force behind MIM's rise in popularity is that the process is well suited for the high-volume manufacture of relatively small, complex components requiring high strength, high performance and cost efficiency. MIM Technology Fits The Mold For Customer Needs
Metal Injection Molding combines the shape making capabilities of plastic injection molding with the material flexibility of powder metallurgy. The basic process uses pressure and heat to form precision metal parts and shapes. Using fine metal powders in combination with a thermoplastic binder, the mixture is heated and injected into a mold. When ejected from the mold, the resulting "green part" is typically 15-to-25% larger than the finished product. It is then exposed to heat, solvents or a combination thereof to remove the binder material, leaving a part comprised of microscopic lattice-work metal. This part is finally passed through a sintering furnace, which fuses and shrinks the metal, creating a high-density, complex and precisely shaped part that exhibits properties approaching that of wrought material. Alloys and stainless steels, along with other non-ferrous alloys such as titanium, are common materials used in MIM. Advantages Over Conventional Metal-Forming Processes
"MIM is attractive because it produces consistent, complex-geometry components for high-volume, high-strength and high-performance applications," AFT's Andrew Hanson, Vice President of Sales and Marketing, told Modern Plastics magazine in August of last year. Automation coupled with microprocessor process controls allow for the production of custom-engineered parts in large quantities while maintaining consistent quality control. MIM is economically attractive to manufacturers, as well — especially against parts that require machining. Machined parts require a considerable amount of labor and a lot of material is lost during the process. When parts are molded in mass quantities, MIM-type parts can offer substantial savings. Furthermore, the more complex the part, the more cost reduction the customer can realize. Its unique process capabilities also allow for advanced fabrications such as combining components into one complex geometry or co-molding and bonding dissimilar materials — capabilities that machining and even die-casting cannot match. Used to produce intricate parts as small as 5 mm in diameter as well as larger components, MIMs flexibility in a variety of applications — as well as cost viability — will most likely continue to drive its continued growth in the market. Furthermore, new developments and capabilities, such as three-dimensional shape making with material properties similar to conventional powder metallurgy, will only help to expand MIM's applications in more industries across the board. |
