MIM, like injection molding, has no limits to shape design. Because the MIM is a molding process, additional product features do not add cost, making the MIM an ideal way to combine individual parts into multifunctional products. The MIM design rules are very similar to injection molding and thus apply to almost all products.
The reference design for the accuracy of MIM net shaping is usually ±0.5% of the size. Some features of the net molding up to ±0.3%. As with other technologies, the higher the accuracy requirement, the higher the cost, so modest tolerance requirements are encouraged where quality permits. Tolerances that cannot be achieved in a single MIM formation can be achieved with the aid of surface treatment.
Weight and dimensions
The MIM is especially suitable for parts weighing less than 100g, less than 50g is the most economical. However, parts weighing up to 250g can also be handled. The main cost of the MIM process is raw materials, so MIM uses new technology to minimize the weight of components. As with plastic products, the weight of components can be reduced through cores and supports without compromising product integrity. The MIM stands out in terms of very small and micro components, and it is possible to weigh less than 0.1 grams. Weight is not a limiting factor and products over 250mm in length can be handled.
Wall thickness less than 6 mm is best for MIM. Thicker walls are also available, but the cost increases due to longer processing times and the addition of additional materials. In addition, a very thin wall less than 0.5mm can also be realized for MIM, but it has high requirements for design.
The MIM is a highly flexible process, and yields that require thousands to millions of dollars a year can be achieved very economically. Like casting and injection parts, MIM requires customers to invest in molds and tools, so for small batches of products, cost estimates are often influenced.
The Raw Material
The MIM can handle a wide range of materials, including ferroalloys, superalloys, titanium alloys, copper alloys, refractory metals, hard alloys, ceramics, and metal-matrix composites. Although non-ferrous aluminum and copper alloys are technically feasible, they are usually treated in other, more economical ways, such as die casting or machining.