What is the connection between metal powder metallurgy and metal powder injection molding?

 

Date：[2024/2/20]
 

Injection molding is a method of forming powder metallurgy parts. There are roughly two types of powder metallurgy parts molding: compression molding and injection molding
1. Powder metallurgy requires injection molding technology:
The production process of metal powder includes steps such as powder preparation and powder mixing. To improve the formability and plasticity of powders, plasticizers such as engine oil, rubber, or paraffin are usually added. Metal powder is pressed into the desired shape under a pressure of 15-600MPa. There are many types of compression molding, and in practical industrial applications, I personally feel that compression molding is widely used. Cold closed steel mold pressing, cold isostatic pressing, hot isostatic pressing, and warm pressing all belong to pressing forming. Compression molding, using dry powder to fill the mold by gravity and forming through external pressure extrusion. Injection molding, using very fine powder and a large amount of thermoplastic binder to inject into the molding mold. There are also two special methods for processing powder metallurgy parts: powder forging and powder rolling.
2. Injection molding is a new powder metallurgy forming method:
Injection molding is a new powder metallurgy near net forming technology that has emerged from the plastic injection molding industry. As is well known, injection molding technology produces various complex shaped products at low prices, but plastic products have low strength. To improve their performance, metal or ceramic powder can be added to the plastic material to obtain products with high strength and good wear resistance. In recent years, this idea has evolved to maximize the content of solid particles and completely remove the binder and densify the formed billet during subsequent sintering processes. This new powder metallurgy forming method is called metal injection molding.

Powder injection molding is a new type of near net forming technology that combines powder metallurgy technology with plastic injection molding technology and metal die-casting molding technology. It is generally used to produce small-sized and complex shaped products. Powder metallurgy and injection molding are complementary and used according to the characteristics of the product.