MIM - Metal Injection Modeling

Published on Monday, 24 October 2011

 

Metal Injection Modeling (MIM)
MIM is an advanced technology that combines the shape-making capability of Plastic Injection Molding and the metal flexibility of powder metallurgy. It provides a new alternative from conventional forming technologies .MIM minimizes machining and secondary operations through net shape production while produce small intricate metal components.

By taking advantage of extremely accurate mold, injection, and design flexibility, MIM would be able to offer cost efficient for moderate-to-high production volume to manufacture parts that require more complex Geometries

 

Characteristics

 

1. Complex Shapes
3-dimensional parts can be produced.
Suitable for intricate and complex Geometries.

2. Good Dimension Control
within +/- 0.4% general tolerance can be achieved by accurate molding and sintering. Utilizing proper post machining, products tolerance can be promoted to m order.

3. High Material Density & Strength
mechanical properties resulted from the Relative Density > 96%

4. Good Surface Finishes
The finishing is good enough for most applications without further polishing and good for surface treatment.

5. Wide Range of Available Alloys, Composites, and Properties

Fe-Based

2%~50% Ni-Fe ; Fe-Si ; Fe

Stainless Steel

304L , 316L , 434L, 440C , 420F , 17-4PH

Steel

M2, 4340

Alloys

Tungesten alloys, Magnetic materials alloys, Copper alloys, Cobalt alloys

Pictures of the production treatment:

The first stage is mould production for injection similar as for plastic.

The metal injection molding process uses superfine metal powder, blended with a binder material and injected into a mold using modified injection molding equipment. The binder is extracted and the part is sintered to nearly full densification.

MIM_kneading

 

Blending the material.

 

 

After the injection the parts are moving to the furnace for the

binding material extraction. In this treatment the parts are losing about 13% of their volume and get the final dimensions.

The next stage is the sintering. The parts are sintered to nearly full densification. The treatment is done by heating the metal little bit under the melting point and forcing the best binding between the material particles. This treatment is done in special furnaces with accurate temperature control Like in the next picture:

 

Now we have the finished product in hand, but still need polish:

After the polish we need oven to dry the parts.

QC inspection is "must" in this industry and we are testing the surface quality, hardness, density, elongation and tensile strength and more.