Breviary Technical Ceramics




Steatite is a ceramic material based on natural raw materials and consists mainly of soapstone (Mg(Si4O10)(OH)2), a natural magnesium silicate, with the addition of clay and feldspar or barium carbonate. Steatite is usually sintered to a high density.
The type of flux used influences the electrical properties of this material, leading to a distinction between normal steatite and special steatite, also known as high-frequency steatite.
Special steatite is defined in international standards as steatite with a low loss factor, and is not only used in low-loss high-frequency parts, but because of its excellent workability it is also used for the manufacture of components with thin, constant thickness. This allows thermally induced mechanical stresses to be controlled.
This material also permits the economical manufacture of products with very small tolerances due to its low shrinkage during sintering. It is also less abrasive to tools than any other ceramic, making it particularly suited to dry pressing.

Magnesiumsilikate (C 200)

Figure 4: Steatite (C 221) surface with firing skin

Special steatite possesses excellent mechanical and dielectric properties, and has been used for more than 90 years in various applications in electrical engineering, for electronic parts and in heat engineering. Typical applications include sockets, control housings, insulating beads, low-voltage power fuses and base plates.
For special applications such as heating cartridges, porous steatite is often used, since it can be easily machined even after sintering, and has a very good thermal shock resistance.


<< back   home   next >>