Silicon Carbide (SiC) is one of the most popular high performance tribo-materials, which has been commercially available for more than twenty-five years. Its features include:
· Excellent abrasion and wear resistance
· Excellent corrosion resistance
· Low coefficient of friction
· Low coefficient of thermal expansion
· High thermal conductivity
· Hardness greater than Tungsten Carbide
Different grades of Silicon Carbide are available as following:
· Reaction Bonded Silicon Carbide (RB SiC) - a very economical material which gives excellent wear characteristics, as well as good chemical resistance.
· Sintered Silicon Carbide (SSiC) - the absence of free silicon makes it most resistant to chemically-aggressive fluids, and ideal for high temperature applications.
· Graphite-Loaded Silicon Carbide - this is a composite of silicon carbide and free graphite. Graphite is added to RB SiC (RB SiC + C) or SSiC (SSiC + C), to improve tribological behavior by enhanced lubricity.
| Parameter | Unit | RB SiC | SSiC |
| Density | g/cm3 | 3.0 - 3.05 | 3.1 |
| Free Silicon Content | - | 12% | - |
| Crystal Size | µm | 8 - 20 | 5 - 7 |
| Hardness | Rockwell | HRA 90 | HRA 93 |
| Compressive Strength | MPa | 2700 | 3000 |
| Flexural Strength | MPa | 400 | 400 |
| Fracture Toughness | MPa | 4.3 | 4.5 |
| Elastic Modulus | GPa | 390 | 410 |
| Poisson's Ratio | - | 0.15 | 0.15 |
| Coefficient of Thermal Expansion | 1 x 10-6 / K | 4.3 | 4.3 |
