Silicon Nitride Technical ceramics materials Morgan Advanced Ceramics, Stourport

Silicon Nitride has good high temperature strength, creep resistance and oxidation resistance. In addition, its low thermal expansion coefficient gives good thermal shock resistance compared with most other ceramic materials. It is dimensionally very stable and offers excellent corrosion resistance. At Morgan Advanced Ceramics, Stourport, Silicon Nitride is produced in two grades: Reaction Bonded Silicon Nitride (RBSN) and Sintered Silicon Nitride (SSN). RBSN is made by direct reacting compacted Silicon powder with Nitrogen, and producing a relatively low-density product compared with Sintered Silicon Nitride, however the process has only a small volume change allowing net shape forming. SSN materials are made with sintering aids and offer better physical properties for more demanding applications.

Silicon Nitride is electrically insulating and is therefore used in support structures in induction heating equipment. It also finds application in other heat treatment roles since it retains its high strength at high temperatures. The material is used throughout the welding industry because of its thermal shock behaviour and resistance to attack from molten metal. Because of its excellent corrosion resistance the material finds many applications where brazing and soldering jigs are required as attack from spatter is minimal. Weld location pins used for the precision alignment of nuts by resistance welding use Silicon Nitride as it offers accurate and repeatable nut location and extended lifetime performance (reducing downstream in-line inspection). Sintered Silicon Nitride (SSN) exhibits very high wear resistance and is used where minimal erosion is essential.

Typical characteristics include:

Excellent wear resistance/hardness
Low thermal expansion
Good chemical corrosion resistance
High temperature performance
Good thermal shock behaviour
Good flexural strength
Low weight
High Stiffness
Electrically insulating

Typical applications include:

Molten metal handling (crucible/riser tubes)
Brazing jigs
Welding jigs and fixtures
Weld location pins
Bearings and rollers
Semiconductor fabrication
Dental heat treatment supports
TIG welding nozzles
Plasma welding nozzles
Induction heating coil supports
Thermocouple sheaths
Glow plugs
Cutting tools

Morgan Advanced Ceramics, Stourport
Bewdley Road, Stourport-on-Severn, Worcestershire, DY13 8QR, England
Tel: +44 (0)1299 827000 | Telefax: +44 (0)1299 827872

Morgan Technical Ceramics is a Global Business Unit of the Morgan Crucible Company plc.
It comprises Morgan Advanced Ceramics and Morgan Electro Ceramics