Metal Injection Molding (Metal Powder Injection Molding, or MIM) is a traditional Powder metallurgy technology and plastic Injection Molding technology of the combination of a high and new technology. MIM began in the late 1970 s, in the past the lack of proper powder and raw material price is too high, imperfect knowledge platform, the technology is not mature, people understand and market accept time is not long, production (including mold manufacturing cycle is too long, investment is not enough, its development and application is relatively slow.To solve the problem of the difficulty of MIM technology, promote the MIM technology is practical, the mid – 80 – the United States has an advanced powder processing plan, the research content covers 18 topics related to the injection molding.Then Japan, Germany, etc. Also a positive research on the development of MIM.With the deepening of the MIM research and development of new type of binder, pulverizing technology and the advance of degreasing process, to the early 90 s has achieved industrialization.After more than 20 years of efforts, now the MIM has become the international field of powder metallurgy is developing rapidly, the most promising a new net shaping technology and has been hailed as “the most popular metal parts forming technology”.
The automotive industry: A major consumer of MIM parts
Automobile manufacturing industry is the biggest user of MIM part, 6 o % of total sales accounted for about the MIM parts in according to the American metal market statistics, in 1990 the United States every 10 cars with MIM parts.With l5 9 kg, 1999.9 kg.Increased by 46% with M1M technology in the production of auto parts material is generally 2 Fe, ni, Fe – 0.4 c a 1 cr a 0.75 mn a 0.2 mo Fe 2 c_0 a 0.5 cr a 0.6 a 0 5 mn ni and other low alloy steel, also use a small amount of stainless steel.
The automotive sector has become a major consumer of MIM, and parts of high complexity are used in engines, gearboxes, turbochargers, locking mechanisms, steering systems and electronic systems, to name just a few.
Rocker Arms for BMW engines
An example is the roller following type rocker arm shown in Fig. 20. This rocker arm for engines with a variable valve stroke is made from low alloy steel. It features a hollow configuration, saving weight, which is difficult to achieve by other processes.
The variable valve lift enhances the engine performance and reduces fuel consumption. Around 4.5 millions parts are produced annually using a hardenable 50NiCrMo2.2 steel powder alloy.
Shift lever
This extremely high volume MIM component is part of a passenger car’s manual transmission.
The component is shown in the various manufacturing stages: moulded, sintered, hardened, and assembled with a shaft.
The material is Fe-2% Ni. The part is case hardened after sintering.
Turbocharger vane
This MIM variable nozzle vane is produced in very high volumes for automotive diesel turbochargers. The part meets strict dimensional tolerance requirements, as close as ±0.015mm on the wing profile, which was achieved with machining.
It is produced using a special tool that has a unique sliding function when opening, reducing deformation during ejection. MIM production offered a 20% cost saving.
The production of MIM superalloy components is now far advanced, with an ever increasing market share. Materials such as Inconel 713 are readily available as MIM feedstocks.
MIM processing, thanks to the finely dispersed powders used, delivers parts with a very homogeneous microstructure, which improves significantly on the microstructure of an investment cast product.
Harber Metal Group was founded in 2014 and is a national high-tech enterprise integrating R&D and production of powder metallurgy. The mim company has set up R&D center, testing center, metal powder forming (PM) division, powder injection molding (MIM) division and other industrial supporting facilities. It is a specialized, refined, special and new enterprise in Guangdong Province, an innovative enterprise in Guangdong Province, a science and technology small giant enterprise in Dongguan City, a director unit of Guangdong Powder Metallurgy Industry Technology Innovation Alliance, and an initiator of Dongguan Advanced Powder Metallurgy Cluster Promotion Center.
