Synthetic Steatite

high temperature pressed ceramic steatite

Pressed Technical Ceramics : Synthetic Steatite

Pressed ceramic products complete the range of ceramics supplied by Final Advanced Materials. This range is suitable for applications which are subject to less severe constraints. The requisite properties for these applications are achieved by firing to a temperature in excess of 1,000 °C, i.e. a temperature which is lower than that required for the production of sintered or machinable ceramics.

Parts are produced by shaping in dry presses, by a liquid method, or by extrusion. Treatment is possible in the raw state.

Two types of synthetic steatite, by opposition to natural steatite which is used in machinable ceramics, are avalaible:

Non-Porous Steatite

Non-porous steatite is a very delicate mineral, the main component of which is talc. It provides a cost-effective option for insulation and machining, without the necessity for particular tooling. Its electrical resistance remains high, even at high temperatures, and it shows good mechanical resistance.

Porous steatite

Porous steatite has similar properties to normal steatite. However, it shows a lower mechanical resistance, and is more resistant to thermal impacts, due to its porosity.

Applications of Steatite Pressed Technical Ceramics

  • Support for heating conductors
  • Spark protection
  • Gas engineering
  • Electric heating systems
  • Components for cartridge heaters
  • Electric heat accumulators
  • Electrical resistors

Benefits of Steatite Pressed Technical Ceramics

  • Hardness
  • High mechanical resistance
  • Dimensional stability, even at high temperatures
  • Resistance to wear and corrosion
  • Electrically insulating
  • High-temperature withstand
  • Chemical resistance
  • Dielectric and ferro-electric properties

Design

Ceramics are materials which are subject to particular design considerations, as they are not ductile and have a very high melting point. Preliminary powdering is necessary, prior to the consolidation of the material form at a high temperature. Various processes are available for this purpose: these include the liquid, plastic, or dry method.

Final Advanced Materials employs the liquid method for the formation of its basic ceramic products. The powdered raw material is dispersed in a solvent, together with a binder. This solid material in suspension forms the ceramic slip. It is then compacted in a tool in order to obtain the desired component. This step is described as extrusion. The extrudate must then be allowed to dry, before being fired at a high temperature. During sintering, the material grains bond together to consolidate the final product.

Technical Data of Steatite Pressed Technical Ceramics

Property

Unit

Steatite

Porous Steatite

DIN EN 60 672 Identification

C221

C230

Composition

%

MgO•SiO2

MgO•SiO2

Density

g/cm3

2.7

> 1.8

Bulk Porosity

%

< 0.5

< 35

Colour 

whitish

whitish

Mechanical Characteristics at 20 °C

Hardness on Vickers’ Scale HV10 

MPa

780

-

Compressive Strength 

MPa

> 900

> 100

Flexural Strength 

MPa

> 140

> 30

Elastic Modulus

GPa

110

-

Thermal Characteristics

Max. Operating Temperature 

°C

1,000

1,000

Specific Warmth at 20 °C 

J K−1 kg−1

800-900

800-900

Thermal Conductivity at 100 °C 

W.m-1.K-1

2-3

1.5-2

Expansion Coefficient from 20 to 1,000 °C 

10-6/K-1

8-9

-

Electrical Characteristics

Electrical Resistivity

at 20 °C

Ω.m

> 1011

-

at 600 °C

> 105

105

Dielectric Strength

kV/mm

15

-

Physical variables included in this documentation are provided by way of indication only and do not, under any circumstances, constitute a contractual undertaking. Please contact our technical service if you require any additional information.