Metal Injection Molding MIM is a kind of suitable for small production, 3 d complex shape and near net forming technology with special performance products.The technology is introducing modern plastic injection molding technology of powder metallurgy and form a new type of powder metallurgy net-shape forming technology.
The basic process is: all kinds of fine metal powder (generally less than 20 microns) according to certain proportion with the default binder, made with the rheological properties of feed, by injecting machine injection mold cavity forming blank parts, blank after removing binder and high temperature sintering, can be all kinds of metal parts.Flow chart is as follows:
The ideal MIM metal powder?
Powder granularity, tap density and particle shape is decided powder can successfully used in MIM process of key performance indicators (kpis).The MIM process requirement raw material powder is very fine (~ 10 microns), to ensure uniform dispersion, good rheological properties and large rate of sintering.
Ideal of MIM in powder is: the powder particle size 2 ~ 8 microns;The apparent density 40% ~ 40%;Tap density of more than 50%;Powder particles for nearly globose, larger than the surface.
At present, MIM metal powder raw materials including iron, nickel, titanium, stainless steel, precious metals, alloys and other materials.More to the diversified development at the same time, such as structural materials and functional materials, magnetic materials, etc.
Mainly has: method of making the MIM powder carbonyl method, ultra-high pressure water atomization method, high pressure gas atomization method, plasma spraying method and laminar flow atomization method.Different powder preparation technology of powder particle size, particle shape, microstructure, chemical properties and the manufacturing cost has different effects.