Indo-US MIM relies on Wittmann Battenfeld for metal injection moldingChristian Kniezanrek, Senior Sales Manager, Wittmann Battenfeld GmbH, Kottingbrunn/Austria

Powder injection molding is a proven process to produce injection-molded parts from metallic or ceramic compounds. Wittmann Battenfeld GmbH, Kottingbrunn, Austria has been one of the pioneers in developing this technology from the very beginning. Wittmann Battenfeld can look back on many years of cooperation with the market leader, Indo-US MIM Tec Pvt. Ltd, based in Bangalore, India. Following its foundation in 2001, this processor soon developed into one of the most renowned metal injection molders worldwide. On its production floor, Indo-US MIM relies on machinery and equipment from Wittmann Battenfeld. The PIM process (powder injection molding) is used to produce complex geometries with high dimensional accuracy in large quantities and at low cost. With its special advantages of high precision and repeatability, this process is optimally suited for cost-efficient mass production.

Description of the process

Metal injection molding (MIM) is one of two powder injection molding (PIM) applications. The other is ceramic injection molding (CIM). With the benefits of injection molding, a process proven in plastics processing for many decades, the advantage of powder injection molding over mechanical forming processes lies in the fact that additional complexity of the manufactured parts does not cause any additional costs. It allows the implementation of an efficient manufacturing process with excellent tolerances for large quantities and/or technically advanced, complex parts (including micro parts). Although the shrinkage in powder injection molding is about 15 - 20 % (depending on the binder content and the grit size distribution of the powder), it is still possible to produce high-precision filigree parts thanks to the high repeatability of this process. Molds for the production of 襊IM parts must be manufactured according to special design guidelines and from wear-resistant tool steel. This allows the production of highly integrated molded components, which, in turn, contributes to minimizing the overall costs. This process even has the edge over precision casting in meeting the rising demand for complexity, large quantities and high quality standards, together with falling prices.

How the process works

The entire process consists of four steps:

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The first step is blending the powder with a binder to obtain the teedstock. The powder content is normally the maximum possible or close to the maximum, i.e. about 60 % of the total volume. Some parameters such as shrinkage can be influenced by varying the powder and the binder. Ready-mixed feedstocks are commercially available.

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The second step is the production of molded parts on an injection molding machine, a process similar to injection molding of thermoplastic materials. The resulting parts are so-called green parts.

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The third step is removal of the binder - normally by a thermal or chemo catalytic process - to obtain the so-called Drown parts.

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The Drown parts are then sintered to produce the finished components.

Indo-US MIM, the market leader in PIM

Indo-US MIM is a well-known manufacturer of metal injection molding applications, specializing in the production of highly complex precision parts. Its main customer base is in the automotive, aviation, telecommunication and medical technology industries. With sales and service subsidiaries in Europe, America and Asia, Indo-US MIM offers worldwide customer support, from product design and construction to comprehensive after-sales service. With more than 25.000 m2 of production floor, Indo-US MIM has the largest and most modern metal injection molding facility worldwide. Its R&D department develops aAdidas Glitch Skin