The sintering process of powder metallurgy is a form of heat treatment where the conventional sintering process for powder metallurgy products heats the material just below its melting point. Standard sintering temperatures allow the metals to retain their beneficial properties while melding them tightly together. So do you know that too high sintering temperature will reduce the performance of powder metallurgy products?
Many factors affect the properties of sintered bodies, namely powder properties, molding and sintering conditions. Factors of sintering conditions include heating rate, sintering temperature and time, cooling rate, sintering atmosphere and pressure conditions.
The sintering temperature and length of time can affect the porosity, density, strength and hardness of the sintered body. High sintering temperature and long heating time will reduce product performance and even lead to scorch defects in powder metallurgy products, while low sintering temperature or long heating time may cause performance degradation due to the sintering process.
The sintering atmosphere usually used in powder metallurgy is a reducing atmosphere, vacuum, hydrogen atmosphere, etc.; the sintering atmosphere directly affects the properties of the sintered body; sintering in a reducing atmosphere can prevent the burning of the compact and allow the reduction of surface oxides. For example, iron and copper-based products are typically decomposed using gas or ammonia, while cemented carbide and stainless steel typically use pure hydrogen. Active metals or refractory metals, cemented carbides containing Tic alloys and stainless steels can be used for vacuum sintering.
