Powder metallurgy production process

(1) Production of powder. Sintering differs from metal melting in that at least one element remains in the solid state during sintering. During the sintering process, a series of physical and chemical processes, such as diffusion, recrystallization, fusion welding, compounding and dissolution, become metallurgical products with certain porosity.

(2) Press molding. The powder is pressed into a desired shape under a pressure of 500 to 600 MPa. [1]
(3) Sintering. In general, sintered parts can be used directly. However, for some sizes, parts requiring high precision and high hardness and wear resistance are subjected to post-sintering treatment. Post-treatment includes coining, rolling, extrusion, quenching, surface hardening, oil immersion, and infiltration. It is carried out in a high temperature furnace or a vacuum furnace which protects the atmosphere. The production process of the powder includes the steps of preparing the powder, mixing the powder, and the like.
(4) Post-processing. Plasticizers such as gasoline, rubber or paraffin are usually added to improve the moldability and plasticity of the powder.