ASK & WE ANSWER
FREQUENTLY ASKED QUESTIONS
Frequently Asked Questions
The best way to realize the full benefits of MIM is to apply the technology early in the design phase in your product development cycle. Indo-MIM will assist you in the application of MIM whether it is a new component or a conversion from an existing metal forming technology.
Almost all kinds of metal alloy can be used in the MIM process. Typical alloys include high strength steels, stainless steels plus Ni and Co super alloys. Other materials processed include refractory metals, titanium and copper alloys. Low melting point alloys like brass, bronze, zinc and aluminum are possible but not usually economically viable by the MIM process. Check the Indo-MIM materials selection chart for the full range of MIM materials processed.
MIM (Metal Injection Molding) is a manufacturing technology that combines the shape making complexity of Plastic Injection Molding with the material flexibility of Powder Metallurgy.
Fine metal powders are combined with thermoplastic and wax binders to form a feedstock. When heated, the feedstock becomes a viscous slurry which is then injected under high pressure into an engineered mold to form the desired shape component. Upon cooling, the part is ejected from the mold and then subjected to a process (called debinding) to remove binder constituents. The final step (sintering) subjects the part to high temperature in a controlled atmosphere to fuse the metal powders together into a near fully dense solid.
No, only the binders are melted allowing the powders to flow like a plastic material. Upon cooling the binders solidify giving the part strength for handling. The part must be subsequently sintered to high density to achieve the required mechanical properties.
Conventional PM uses high, uniaxially applied pressure to coarse metal powders in a die set to produce moderately complex components. Typically, no further densification is gained during the sintering process. Densities achieved by this method are typically in the range of 80-90% of theoretical which limit the physical properties that can be achieved for the given alloy. MIM products are not limited in shape complexity due to the flexibility of the injection molding process. The fine metal powders used – combine with higher sintering temperatures to allow MIM to achieve near full density in the final article. This allows MIM products to have similar properties as wrought materials.
No, the part will not change size in the debinding phase of the process. However, since sintering achieves near full density of the powders, the part will undergo a size change of up to 20%.
Typical MIM densities achieved are ≤ 96% of theoretical. Properties vary depending upon the alloy chosen however they will be similar to wrought material.