The sintering furnace is one of the most important pieces of equipment in powder metallurgy production and is designed according to the requirements of the sintering process. The most common type used in powder metallurgy is the electric furnace Z.
The sintering of powder metallurgy products is, in essence, a heat treatment process, similar in some ways to the heat treatment of dense metals. However, due to the special properties of powder raw materials, powder metallurgy sintering has the following characteristics:
- Large free surface area of powder compacts: The sintering process generally requires a protective atmosphere and is very sensitive to the type of sintering gas.
- Surface oxide films on metal powders: These oxides hinder contact between metal particles, so reduction of oxides during sintering is necessary.
- Stress from compaction: Stresses generated during the pressing of compacts must be relieved before or during sintering.
- Volatile additives in compacts: Any volatile components must be removed during the heating stage before sintering.
- Possible liquid phase formation: Compacts may develop a liquid phase during sintering.
- Low compact strength: Compacts must not collide, and material transport during sintering must be smooth.
- High sintering temperature: Sintering temperatures are higher than typical heat treatment, so precise temperature control is essential.
In summary, powder metallurgy sintering furnaces are heat treatment devices that use metal powders (or mixtures of metal and non-metal powders) as raw materials, which are formed and sintered to produce metal or alloy parts. They are mainly used for pressed iron-based, copper-based, and other powder metallurgy products.