Powder Microinjection Molding Technology

Powder injection molding is a new technology that combines traditional Powder Metallurgy with plastic injection molding. It allows for the direct manufacturing of parts with complex shapes, minimizing the need for machining and saving raw materials. This technology can be used with various materials such as metals, alloys, and ceramics. It also enables fully automated continuous production, high efficiency, excellent material performance, and high dimensional accuracy.

The process involves mixing solid powder with polymer and additives, granulating the mixture, injecting it into a mold cavity, and then removing the binder through chemical or thermal decomposition. The final product is obtained through sintering and densification.

In recent years, there has been a rapid development of microsystem technology, which requires the manufacture of three-dimensional micro-complex components. Existing micro-processing technologies have limitations in terms of production efficiency and scalability. Powder microinjection molding has emerged as a potential solution for large-scale production of micro components. It is used for the continuous manufacture of parts with microstructured surfaces and microstructures. The process steps are similar to traditional powder injection molding, but with smaller particle sizes and specific surface area, as well as stricter process conditions for degreasing and sintering.

Germany, Japan, Singapore, the United States, and the United Kingdom are among the countries conducting research on this technology. In China, Beijing University of Science and Technology, Central South University, and Dalian University of Technology have made significant progress in this field. For example, Beijing University of Science and Technology has developed a mold for powder micro-injection molding with independent intellectual property rights and successfully produced micro gears with addendum circle diameter less than 1mm using carbonyl iron powder and iron-nickel alloy powder.