Metal powder injection molding for micro gears

The size of metal powder particles used in MIM process is 0.5-20um. Theoretically, the finer the particles are, the larger the surface area will be and easier to shape and sintering.At present, the main production methods of MIM powder are: water atomization method, gas method, each method has advantages and disadvantages: water atomization method is the main powder making process, high efficiency, mass production is more economical, can make the powder fine, but the shape is irregular, and conducive to shape preservation, but more binder, affect the accuracy.In addition, the oxidation film formed by the reaction of water and metal at high temperature hinders sintering.Gas atomization is the main method to produce MIM powder. The powder produced by it is spherical in taste, low in oxidation degree, requires less binder, and has good formability. However, the extremely fine powder has low yield, high price and poor shape retention.Powder selection should be considered from MIM technology, product shape, performance, price and other aspects.Water atomized 316L stainless steel powder is used because gears are used in corrosive environment.