Advanced Ceramic Mechanical Seals
Mechanical seals are used in the Chemical & Process Industries as seals in rotating equipment, such as pumps and compressors. For example, in a pump, when a shaft rotates, the liquid can leak out between the shaft and the pump casing. In this case, to prevent leakage a mechanical seal would be used, which basically consists of a hard material embedded in the casing and a softer material in the rotating shaft. These are made to be in intimate contact. The choice of seal materials depends on the material being pumped, its chemical reactivity, the temperature and the pressure.
Sialons are silicon nitride based advanced ceramics and are characterised by outstanding wear and corrosion resistant properties. In many cases, Syalon 101 makes an excellent choice for the hard seal material. Due to its extreme hardness, high strength and toughness, and low coefficient of friction, Syalon 101 has excellent wear resistance. This combined with outstanding chemical stability, and excellent thermal properties, such as thermal shock resistance, make it an obvious candidate material for many mechanical seal applications.