What are the process characteristics of powder metallurgy? What are the main technological processes?

What are the process characteristics of powder metallurgy? What are the main technological processes?

Powder metallurgy is not only a material manufacturing technology, but also a material processing technology. For material manufacturing, powder metallurgy can produce materials with special properties that cannot be produced by ordinary melting and casting methods. What are the process characteristics and processes of powder metallurgy? The following is the share of zhongwei precision editor.

What are the process characteristics of powder metallurgy? Powder metallurgy process can minimize the segregation of alloy components and eliminate the coarse and uneven casting structure. It plays an important role in the preparation of high-performance rare earth permanent magnetic materials, rare earth hydrogen storage materials, rare earth luminescent materials, rare earth catalysts, high-temperature superconducting materials, and new metal materials (such as Al-Li alloy, heat-resistant Al alloy, superalloy, powder corrosion resistant stainless steel, powder high-speed steel, intermetallic compound high-temperature structural materials, etc.).

Powder metallurgy is the combination of metal metallurgy process and ceramic sintering process. It usually goes through the following processes:

1、 Powder preparation and compaction

Powders are usually prepared by mechanical crushing, atomization and physical-chemical methods. The prepared powder is screened and mixed, mixed evenly and added with appropriate plasticizer, and then pressed into shape. The atoms between the powder particles combine into a whole with certain strength through solid phase diffusion and mechanical occlusion. The greater the pressure, the greater the density of the parts and the corresponding increase in strength. Sometimes, in order to reduce the pressure and increase the density of the parts, the hot isostatic pressing method can also be used.

2、 Sintering

Place the pressed parts in a closed furnace with reducing atmosphere for sintering, and the sintering temperature is about 2/3~3/4 times of the melting point of the base metal. Due to the diffusion of different kinds of atoms at high temperature, the reduction of oxide on the surface of powder and the recrystallization of deformed powder, the powder particles combine with each other, improving the strength of powder metallurgy products, and obtaining the structure similar to that of ordinary alloys. There are still some tiny pores in the sintered parts, which belong to porous materials.

3、 Post-processing

Generally, the sintered parts can reach the required performance and can be used directly. However, sometimes necessary post-treatment is also required. For example, precision pressing can improve the density and dimensional shape accuracy of the parts; The mechanical properties of iron-based powder metallurgy parts can be improved by quenching and surface quenching; Immerse oil or other liquid lubricants for lubrication or corrosion resistance; Infiltration of low melting point metal into the pores of the parts can improve the strength, hardness, plasticity or impact toughness of the parts.

To sum up, the process characteristics and process of powder metallurgy have been told to you. I hope this article will help you. If you need more relevant information, please come to zhongwei for precise understanding. We will have professionals to answer for you.