Basic process and development direction of the hot

The basic process and development direction of powder metallurgy process

the basic process of powder metallurgy process is:

1. Preparation of raw powder. The existing milling methods can be roughly divided into two categories: mechanical method and physical-chemical method. The mechanical method can be divided into: Although the domestic technology of machinery is not yet mature, crushing and atomization methods; Physical and chemical methods are divided into electrochemical corrosion method, reduction method, chemical method, reduction chemical method, vapor deposition method, liquid deposition method and electrolysis method. Among them, reduction method, atomization method and electrolysis method are the most widely used

2. The powder is shaped into a blank of the desired shape. The purpose of forming is to make the blank with certain shape and size, and make it have certain density and strength. The forming methods are basically divided into pressure forming and non pressure forming. Compression molding is the most widely used in compression molding

3. Sintering of billets. Sintering is a key process in powder metallurgy. The formed compacts are sintered to obtain the required final physical and mechanical properties. Sintering is also divided into unit system sintering and multi-element system sintering. Main technical parameters: for solid-state sintering of unit system and multicomponent system, the sintering temperature is lower than the melting point of the metal and alloy used; For liquid phase sintering of multicomponent systems, the sintering temperature is generally lower than the melting point of refractory components, but higher than the melting point of fusible components. In addition to ordinary sintering, there are special sintering processes such as loose sintering, which need to bear 4000 vehicles, melting and hot pressing

4. Post processing of products. The treatment after sintering can be carried out in various ways according to different product requirements. Such as finishing, oiling, machining, heat treatment and electroplating. In addition, in recent years, some new processes such as rolling and forging have also been applied to the processing of powder metallurgy materials after sintering, and achieved satisfactory results

future development direction of powder metallurgy materials and products:

1. Representative iron-based alloys will develop into large-scale precision products and high-quality structural parts

2. Manufacturing high-performance alloys with uniform microstructure, difficult processing and complete compactness

3. Special alloys generally containing mixed phases are manufactured by enhanced densification process

4. Manufacturing non-uniform materials and amorphous materials is a kind of protective, microcrystalline or metastable alloy for machine equipment

5. Processing unique and non general shape or composition of composite parts. (end)