GEVORKYAN, s.r.o. has Metal Injection Moulding (MIM) in its portfolio, along with powder metallurgy technology. It represents injection of metal materials on injection presses. It is not used in any other Slovak company and majority of surrounding states.
MIM has established itself as a competitive manufacturing process for production of small precision components over the past decades. These components would be expensive by alternative production methods. This technology is ideal for large or small volumes of parts with complex shapes from almost all types of materials. Components produced by MIM technology can be used in various industry sectors such as automotive, locks and security systems, aerospace, garden and agriculture technique, armaments industry, medicine, etc.
Process of MIM
Metal injection moulding (MIM) represents development of traditional sintering (PM) process. It is highly regarded as a branch of this technology. The real breakthrough occurred when it was found possible to incorporate a very high volume fraction of metal powder in a mix so that, instead of a filled plastic part, a plastic-bonded metal or ceramic part is produced.
MIM technology is in general based on three basic processes:
- to choose the right combination (chemical composition) of metal powders and polymers
- injection of material into the form of the final part on injection press
- debinding – binder removal, which is the key step of the whole process
- heat treatment (sintering) of the part
Heated material is injected into the previously designed form according specific customer requirements. After ejection of the part from the mould, the polymer is removed without shape disruption. This process is called debinding. Next step is sintering. During this process, the part obtained significant final mechanical properties and shape.
After sintering there are no residues of powder or polymer. Mechanical properties of MIM parts are on the same level as parts made by usual engineering technologies. At the same time, subsequent secondary operations are used as on metal parts. Parts could be treated by heat, coated, milled, riveted or welded.
MIM technology is more suitable for mass production.
Process of MIM (Source: EPMA)
MIM process step-by-step.
Main benefit of MIM technology is the fact that it allows production of metal products with properties, which should not be expected from plastic material. MIM combines small particles of dust (with typical size between 1 and 40 µm) with plastic binder. Typical proportion is 60 v/o of powder, which requires 40 v/o of binder.
The uniqueness of MIM technology is characterized by many facts. We will mention only few of them:
- wide application,
- complex form of parts,
- high final density, which makes parts equivalent to conventional technologies,
- wide material options,
- high productivity, high material application, very good final surface, good tolerance
- ability to secure also target pores in layers or on specific part places to achieve customer requirements with consideration of part functionality,
- possibility to produce high production amounts,
- recycling (damaged or badly done parts could be recycled or used again).