Process and Characteristics of Metal Powder Injection Molding Technology
MIM (metal powder injection molding) is a new forming technology of powder metallurgy, which is introduced into the field of powder metallurgy.
Firstly, the solid powder and organic binder are uniformly mixed, and after granulation, in the state of heating and plasticizing (~ 150 ℃), the injection molding machine is used to inject into the mold cavity for curing, then the binder in the blank is removed by chemical or thermal decomposition method, and finally the final product is obtained by sintering and densification. Compared with the traditional process, it has the advantages of high precision, uniform structure, excellent performance and low production cost.
MIM process characteristics
The technology of metal powder injection molding is the product of the combination of plastic molding technology, polymer chemistry, powder metallurgy technology and metal materials science. The design idea can be materialized into a certain structure and function quickly and accurately by using the mold to mold the blank and sintering the high-density, high-precision and three-dimensional complex shape structural parts It is a new revolution of manufacturing technology industry that the products can be produced directly in batches.
The process technology not only has the advantages of less conventional P / M process, no cutting or less cutting, high economic benefits, but also overcomes the disadvantages of traditional P / M process products, uneven materials, low mechanical properties, difficult to form thin-walled, complex structures, especially suitable for mass production of small, complex and special requirements of metal parts.
Metal powder for MIM
The particle size of metal powder used in MIM process is generally 0.5 ~ 20 μ m; theoretically, the finer the particle, the larger the specific surface area, and the easier to form and sinter. However, the traditional powder metallurgy process uses coarser powder larger than 40 μm. AEM provides metal powders that can be used for MIM. Please refer to the following table for details:
MIM process uses micron fine powder, which can not only accelerate sintering shrinkage, but also improve mechanical properties, fatigue life, stress corrosion resistance and magnetic properties. Its products are widely used in electronic information engineering, biomedical equipment, office equipment, automobile, machinery, hardware, sports equipment, horology, weapons, aerospace and other industrial fields.