Metal injection molding is most suitable for mass production of small metal parts. As with injection molding, these components may be geometrically complex, thin-walled and detailed. Various ferrous and non-ferrous alloys can be used with metal powder, and the material properties (strength, hardness, wear resistance, corrosion resistance, etc.) are close to forged metal. In addition, since the metal does not melt in the metal injection molding process (different from the metal casting process), superalloys can be used without any negative impact on the tool life.
Very fine metal powders are combined with thermoplastic and wax binders in a precise recipe. A proprietary compounding process creates a homogenous pelletized feedstock that can be injection molded just like plastic. This achieves ultra-high density and close tolerances over high-production runs.
Unlike standard powder metallurgy, which can achieve only 80-90% of theoretical density, MIM results in 95-100%. This means we can achieve close tolerances and reduce costs by producing small, complex parts over high production runs.
The feedstock is heated and injected into a mold cavity under high pressure. This enables us to produce extremely complex shapes and allows for shorter cycle times.
Once molded, the component is referred to as a "green" part. Its geometry is identical to the finished piece but is about 20% larger to allow for shrinkage during the final sintering phase.
Binder removal (debinding) involves a controlled process to remove most of the binders and prepare the part for the final step – sintering.
Once debinding process is complete, the component is referred to as brown.
The brown part is held together by a small amount of the binder and is very fragile.
Sintering eliminates the remaining binder and gives the part its final geometry and strength.
During the metal sintering process, the part is subjected to temperatures near the melting point of the material.
Metal powder sintering refers to the use of infrared laser to instantly heat various metal powders to the molten state to form them. At the initial stage, this technology was developed and studied as a rapid prototyping (RP) technology. However, with the maturity and application of the technology, it is found that the metal powder sintering equipment can be used as a new generation of low-carbon rapid manufacturing equipment. This technology has been used as a new generation of production and manufacturing equipment in many industries.
A professional degreasing furnace is used to gradually and efficiently remove the main binder in the injection blank, and the residual skeleton binder maintains the product shape so that the degreased parts can be moved into the burning stage.
Die casting refers to the injection of metal into the mold cavity through pressure in the melting state. Injection molding refers to the injection of the mold into the mold cavity in the plasticizing state. The temperature is not so high, and the mold accuracy can be higher, so the product accuracy will be higher, it is not easy to have burrs, and the appearance will be better.
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