1. Protective atmosphere: the protective atmosphere is divided into reducing atmosphere and neutral atmosphere, and the reducing atmosphere is divided into hydrogen and decomposed ammonia. In the sintering process, the main role of protecting atmosphere is to protect sintered products from oxidation.

Hydrogen has a strong permeability at a certain temperature and is a non-toxic gas with strong chemical activity. It is often used as a protective atmosphere in the sintering of tungsten, cemented carbide, stainless steel and other refractory powder metallurgy products.

2. Controlled atmosphere: this kind of atmosphere can be divided into exothermic atmosphere (without external heating) and endothermic atmosphere (without external heating), both of which are converted from hydrocarbons.

Exothermic type can be used to control the carbon content of sintered products of powder metallurgy (including injection molding). It can be divided into light type and thick type atmosphere. The carbon potential of light type exothermic atmosphere is very low. The concentrated exothermic atmosphere has a higher carbon potential, which can be used to prevent the oxidation of powder metallurgy iron base and copper base parts and reduce the decarburization of iron base parts.

3, air atmosphere: this sintering atmosphere is mainly through a certain air gas in the sintering furnace, can also be regarded as sintering under atmospheric pressure, generally used in metal composite materials and ceramic materials sintering products.

From the manufacturing of mechanical parts, metal injection molding manufacturing of mechanical parts when a less cutting, no cutting of the new process, can greatly reduce the amount of machining, save metal materials, improve labor productivity.