Metal powder injection molding (MIM) is a new near-net-shape technology of powder metallurgy, which introduces modern plastic injection molding technology into the field of powder metallurgy. The basic technological process is as follows: firstly, the solid powder and the organic binder are mixed and kneaded evenly, after granulation, they are injected into the mold cavity by an injection molding machine in a heating plasticizing state (~ 150℃) for curing, then the binder in the molded blank is removed by chemical or thermal decomposition, and finally the final product is obtained by sintering and densification. Compared with the traditional process, it has the characteristics of high precision, uniform structure, excellent performance and low production cost. Its products are widely used in electronic information engineering, biomedical equipment, office equipment, automobiles, machinery, hardware, sports equipment, watch industry, weapons and aerospace industries. Therefore, it is generally believed that the development of this technology will lead to a revolution in part forming technology, which is known as "the hottest part forming technology today" and "the forming technology of 2 1 century".

It was invented by Parmatech Company in California in 1973. In the early 1980s, many European countries and Japan also devoted great efforts to the research of this technology, which was quickly popularized. Especially in the mid-1980s, this technology has developed by leaps and bounds since its industrialization, increasing at an alarming rate every year. Up to now, 100 companies in more than ten countries and regions such as the United States, Western Europe and Japan are engaged in product development, research and sales of this technology. Japan's competition is very active and its performance is outstanding. Many large joint-stock companies have participated in the promotion of MIM industry, including Pacific Metal, Mitsubishi Steel, Kawasaki Steel, Kobe Steel, Sumitomo Mine, Seiko-Epson, Datong Special Steel and so on. At present, there are more than 40 companies specializing in MIM industry in Japan, and their total sales of MIM industrial products have already surpassed Europe and caught up with the United States. Up to now, more than 100 companies around the world have been engaged in product development, research and sales of this technology, so MIM technology has become the most active frontier technology field in new manufacturing industry, the frontier technology of the world metallurgical industry, and represents the main direction of powder metallurgy technology development.