Silicon nitride ceramics are electrical insulators and are resistant to attack by many molten metals. With low thermal conductivity and excellent thermal shock resistance, silicon nitride ceramics are used in many RF heating applications where the material is in contact with hot metal parts.
The high strength of sintered silicon nitride ceramics has found many applications in the automotive and machine tool industries for bearing and wear parts which run in very arduous abrasive environments.
Gas Pressured Sintered Silicon Nitrides (GPS- SSN)
In recent years, a great deal of research has been carried out on gas pressure sintering, and great progress has been made. Gas pressure sintering of silicon nitride is carryed out at 1 ~ 10MPa pressure, about 2000 degrees Celsius temperature. High nitrogen pressure inhibits the high temperature decomposition of silicon nitride. Because of the high temperature sintering, adding less SINTERING AIDS cases, is sufficient to promote the growth of Si3N4 grain, and get density > 99% high toughness ceramics,containing in situ growth of columnar grains. Therefore the gas pressure sintering either in the laboratory or in the production have got more and more attentions. Gas pressure sintering silicon nitride ceramics is with high wear resistance,high toughness, high strength, can be directly made with complex shapes si3n4 ceramics, which can greatly reduce the production cost and processing cost. And the production process is close to the hard alloy production process, suitable for mass production.