How to choose the forming process for powder metallurgy parts?

How to choose the forming process for powder metallurgy parts?

We know that there are generally two processes for forming powder metallurgy parts: injection molding and compression molding. In general, how do we choose the process for forming powder metallurgy parts. Actually, it's very simple. Let's briefly introduce it below:

Injection molding first involves uniformly mixing solid powder with organic binder, granulating, and then injecting it into the mold cavity for solidification under heating and plasticization (~150 ℃) using an injection molding machine. Then, the binder in the formed billet is removed by chemical or thermal decomposition methods, and finally, the final product is obtained through sintering and densification. Generally, injection molding uses very fine powder, combined with a large amount of thermoplastic binder injected into the molding mold.

Powder compression forming, also known as powder molding, is an early forming method used in powder metallurgy production. In the late 18th and early 19th centuries, Russia and Britain used steel molds to press and manufacture platinum products. Subsequently, the powder compaction forming method gradually improved and was used to press various oil bearing, powder metallurgy antifriction products, powder metallurgy machine structural parts, and other pressed blanks. Since the 1930s, powder pressing and forming has undergone greater development, with continuous improvements in press and mold design, capable of pressing complex shaped parts with higher levels of mechanization and automation. In the actual application process, pressing is widely used, such as our cold closed steel mold pressing, cold isostatic pressing, Hot isostatic pressing, and warm pressing.