Silicon Carbide Seals

Silicon Carbide Seals Picture

Silicon carbide is the ideal sealing material. It has good corrosion resistance, higher mechanical intensity, excellent resisting wear ability and high temperature, good self-lubricity and making-group, low friction factor, good heat-conduction and so on. Therefore, silicon carbide seals also possess the property of excellent resistant-corrosion, high mechanical strength, high thermal conductivity and good self-lubrication. Silicon carbide seals are widely used in many different industries, including spacecraft, machinery, metallurgy, printing and dyeing, foodstuff, pharmaceutical, auto industry etc.

Why make from silicon carbide?
Silicon carbide is a more expensive seals material with the carbon, but it is often used in more demanding applications. For example, blistering is a critical concern with carbon bearing materials. Strangely, the reason why blistering sometimes occurs is not known for certain. The most popular explanation is that a certain amount of material becomes absorbed in the carbon substrate and expands because of frictional heat, thus creating a crater in the seals face. Blistering is most often found in applications involving heavy oils. In some cases, the use of silicon carbide as a mating surface will eliminate a blistering problem.

Silicon Carbide (SiC) physical property

Technical parameter

Unit

RBSiC

SSiC

Sic+C

Ssic+C

Qssic+C

Content of Sic

%

≥90

≥98

≥85

≥92

≥90

Free Si

%

≤10

≤1

≤12

/

/

Elastic Modulus

GPa

≥400

≥410

≥350

≥360

≥180

Temperature

°C

1300

1400

1300

1400

1400

Hardness

HS

110

115

≥105

≥110

≥100

Porosity Rate

%

<0.3

<0.2

<0.5

<0.5

<5

Density

g/cm3

3.00~3.05

>3.10

2.69-2.90

2.70-3.0

2.65

Compressive Strength

MPa

>2200

>2500

>1400

>1600

>800

Fractural Strength

MPa

>350

>380

>150

>160

>100

Coefficient of Heat Expansion

10-6/°C

4

4.2

3.50

3.00

2.50