Metal Powder Injection Molding (referred to as MIM) is a modern plastic injection molding technology into the field of powder metallurgy and the formation of a new powder metallurgy near-net shape forming technology. The basic process is: First, the solid powder and organic binder uniform mixing, the pellet after heating plastics in the state (~ 150 ℃) with the spray forming into the mold cavity stereolithography machine, then use chemical or thermal decomposition method will be blank in the forming binder removal, the final sintering the final product. Compared with the traditional process with high accuracy, homogeneous, high-performance, low cost of production, its products are widely used in electronic information engineering, bio-medical equipment, office equipment, vehicles, machinery, hardware, sports equipment, watches and clocks, weapons and aerospace industries. Therefore, the international is widely recognized that the technology will lead to the development of parts forming and processing technology, a revolution, known as "the most popular parts forming technology" and "shape the 21st century technology."
California, USA Parmatech company invented in 1973, many countries in Europe in the early eighties and have invested great effort in Japan began to study the technology, and rapid promotion. Particularly the mid-1980s, the technology industry since the development of more rapid access to every year increasing at an alarming rate. So far, the United States, Western Europe, Japan and other countries and regions, manganese powder more than 100 technology companies engaged in the process of product development, research and sales. Japan is very active in the competition, and outstanding performance, many large industrial MIM Corporation are involved in the promotion, these companies include Pacific Metals, Mitsubishi Steel, Kawasaki Steel and Kobe Steel, Sumitomo Mining, Seiko - Epson , Daido Steel and so on. In Japan more than 40 companies specializing in MIM industry, its total sales of industrial products MIM had more than catching up with Europe and the United States. So far, there are hundred companies worldwide engaged in the technology of product development, research and sales, MIM technology has thus become the most active new cutting-edge manufacturing technology, is the world's pioneering technology, metallurgical industry, on behalf of the main direction of development of powder metallurgy technology MIM technology.
 Metal powder injection molding is a plastics molding technology, polymer chemistry, metallurgy and metal materials technology such as multi-disciplinary and cross-product through the use of injection molding mold can be blank and rapid manufacturing by sintering high-density, high-precision , three-dimensional structure of complex shape parts can be quickly and accurately design ideas materialized into a certain structure, functional properties of products, and direct mass-produced parts, the manufacturing industry, a new change. The technology not only has less conventional powder metallurgy process, boron powder no cutting or less cutting, cost advantages, and overcome the traditional powder metallurgy products, uneven texture, mechanical properties, low, easy molding thin-walled, complex structure of the shortcomings, particularly suitable for mass production of small, complex and special requirements of the metal parts. Binder mixing process → → → injection molding → degreasing → After the sintering process.
MIM process metal powder particle size used is generally 0.5 ~ 20μm; In theory, the finer particles, the greater the surface area, easy molding and sintering. The traditional powder metallurgy process is used more than 40μm of thick powder. The role of organic adhesive organic adhesive bonding metal powder particles, so that the mixture is heated in a barrel jet rheology and lubricity, powder flow that is driven by the carrier. Therefore, the choice of adhesive is the carrier of the powder. Therefore, the sticky option is to pull the key to the powder injection molding. Requirements of the organic binder: 1. With less, with less adhesive mixture can produce a better flow variability; 2 does not react in the process of removing adhesive and metal powder can not afford any chemical reaction; 3 easy to remove, no residue in the products of carbon mixture.
The metal powder and organic binder evenly blended together to make a variety of raw materials into injection molding mixture. Uniformity of the mixture directly affect their mobility, thus affecting the injection molding process parameters and, ultimately, silicon powder the density and other properties. Spray forming process and the steps the plastic injection molding process is the same in principle, the equipment is basically the same conditions. In the injection molding process, the mixture is heated in a jet into the barrel with a plastic rheology of materials and, where appropriate under pressure into the injection mold, molding the rough. Micro-injection molding blank should be uniform, so that the products in the uniform shrinkage during the sintering process. Extraction blank in the sintering molding must be removed before the blank contained within the organic binder, the process is called extraction. Extraction process must ensure that the adhesive from the rough along the different parts of the small channel between the granule gradually discharged, without reducing the strength of rough. Binder elimination rate generally follows the diffusion equation. Skim sintered porous sintered blank can shrink to a certain density of the organization and performance of products. Although the performance of products and many of the processes before sintering factors, metal powder supplier but in many cases, the final sintering process on microstructure and properties of products have a great, even decisive. Size requirements for post-processing is more sophisticated parts, the need for the necessary post-processing. This process with the conventional metal heat treatment processes the same. Source:http://www.mhcmp.com