The Significance of the Promotion of Powder Forging Technology

At the end of the last century, a new metal plastic forming process, powder forging, was successfully developed abroad. It has forged automobile differential planetary gears and connecting rod forgings, and built the first powder forging production line. It is a competitive non-cutting metal processing method developed by organically combining traditional powder metallurgy technology with precision forging. With metal powder as raw material, it is preformed and pressed in a protective atmosphere, heated and sintered as a forging blank, and forged in a press at one time to achieve precision die forging without flash, and obtain precision forgings with the same density and complex shape as ordinary die forging.

Powder forging is a process that combines powder metallurgy and precision die forging to give full play to the advantages of both. It can mass-produce high-quality, high-precision, and complex-shaped structural parts at a lower cost and higher production efficiency. The powder forging process has been widely recognized by almost all industrial countries

It not only has the advantages of good forming performance of powder metallurgy, but also plays the role of forging deformation in changing the organization and performance of metal materials, and has made new breakthroughs in powder metallurgy production and forging technology. It is a marginal professional discipline, especially suitable for mass production of high-strength, complex-shaped structural parts. Therefore, it has great promotion significance in various industrial fields.

Powder forging process

The general powder forging process is to form a powder with an appropriate formula and mixture in the same way as the manufacture of ordinary sintered parts, and make it into a low-density preform, which is used as a forging blank for hot forging after sintering. When the preform contains a lubricant, a lubricant removal process should be added before sintering. If it is cooled after sintering, it must be reheated before forging. Some degree of machining is usually required before heat treatment after forging. Throughout the process, all heating is carried out in an anti-oxidation protective atmosphere except for short-term forging.

The general powder forging process is to form a powder with an appropriate formula and mixture in the same way as the manufacture of ordinary sintered parts, and make it into a low-density preform, which is used as a forging blank for hot forging after sintering. When the preform contains a lubricant, a lubricant removal process should be added before sintering. If it is cooled after sintering, it must be reheated before forging. Some degree of machining is usually required before heat treatment after forging. During the entire process, except for short-term forging, all heating is carried out in an anti-oxidation protective atmosphere.

Compared with die forging, powder forging has the following advantages:

01 High material utilization rate, reaching more than 90%. The material utilization rate of die forging is only about 50%.

02 High mechanical properties. The material is uniform and non-anisotropic, with high strength, plasticity and impact toughness.

03 Forgings have high precision and smooth surfaces, and less and no cutting can be achieved.

04 High productivity. The output can reach 500 to 1000 pieces per hour.

05 Low forging pressure. For example, for 130 automotive differential planetary gears, billet forging requires a pressure of 2500 to 3000 kn, while powder forging only requires a pressure of 800 kn.

06 It can process materials with poor thermoplasticity. For example, high-temperature casting alloys that are difficult to deform can be used to forge parts of complex shapes by powder forging.

The powder forging process has developed very rapidly, and new process methods are constantly emerging. Such as loose forging, pellet forging, spray forging, powder jacket free forging, powder isothermal forging, powder superplastic die forging, etc. In addition, there are other powder forming methods: powder hot isostatic pressing, powder hot extrusion, powder swing rolling, powder spinning, powder continuous extrusion, powder rolling, powder injection molding, powder explosion forming, etc.