Powder metallurgy is a processing method that uses metal powder as raw material and presses and sinters it to make products. The powder metallurgy process mainly consists of three steps in sequence: granulation, molding, and sintering. First, the main material is decomposed into a powder composed of many fine particles; then the powder is loaded into the mold and pressure is applied to form a compact that conforms to the appearance and size of the part; finally, the compact is sintered.