Material technology (SiC & Carbon)
Mechanical seal faces that rub against each other are an extremely important element, and are therefore made of ceramics for strength and wear resistance reasons.
Eagle Industry uses silicon carbide (SiC) and carbon, and conducts research and development on these materials.
Features of silicon carbide (SiC)
- High hardness: one of the hardest materials after diamond and boron carbide
- Wear resistance: higher wear resistance than cemented carbide
- Low coefficient of friction: approx. 50% of that of cemented carbide → Extends the useful life of seals substantially.
- Heat resistance: approx. 1600ºC in air
- Corrosion resistance: SiC's extremely high chemical stability makes it suitable for many types of corrosive fluids.
|Fabrication method||Feature||Photographed image of structure||Feature|
|Reaction-sintered SiC||Achieves SiC + Si composition by infiltrating Si into an SiC + C compact for reaction.||Achieves SiC + Si composition by infiltrating Si into an SiC + C compact for reaction.|
|Special conversion SiC||Achieves SiC + Si composition by infiltrating Si into base carbon for reaction.||Self-lubrication property of carbon provides excellent sliding characteristics.|
|Atmospheric pressure sintered SiC||Molded SiC powder sintered under pressureless conditions||Atmospheric pressure sintering is a common powder metallurgy technique optimally suited for mass production.
Enabling a high SiC content, this technique produces a material that demonstrates the superb properties of SiC to the greatest extent possible.
|Porous SiC||Atmospheric pressure sintered SiC with dispersed pores||Face materials provided with purposefully dispersed pores retain fluid in them to ensure lubricity and low torque.|
Characteristics of carbon
Specific gravity: approx. 1.8; 2/3 of aluminum, or 1/4 of steel
- Thermal properties
Coefficient of thermal expansion: approx. 4.3 x 10−6/ºC; 1/5 of aluminum, or 1/3 of steel
- Thermal/Electrical conductivity: approx. 120 W/m∙K; twice as high as steel
- Chemical resistance: inactive to all substances except highly acidic substances
|Molded carbon||Molded carbon, with binder being retained through heat treatment at low temperatures, exhibits high airtightness and strength. Eagle Industry designs its original molded carbon to offer properties suitable for specific applications.|
|Baked carbon||In baked carbon, the binder is carbonized by baking. It requires no impregnation since no through-pores are present inside. Eagle Industry designs its original baked carbon to offer properties suitable for specific applications.|
|Non-impregnated carbon||Since it is non-impregnated, it exhibits its intrinsic properties such as heat resistance, corrosion resistance and self-lubricity.|
|Plastic-impregnated carbon||When impregnated with self-lubricating plastic, conventional graphite/carbon-dependent structures become usable under dry and high-temperature conditions.|
|Metal-impregnated carbon||Carbon articles with pores impregnated with various metals display improved strength, thermal conductivity and electrical conductivity.|