Silican Carbide Mechanical Seals
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 mechanical 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 |
If you have interest in buying silicon carbide mechanical seals, please do not hesitate to e-mail us with your specific requirements by : sales@chinatungsten.com
sales@chinatungsten.com;