SiSiC seal rings

SiSiC seal rings (in contrast with those made of pure SSiC) can only be used in acid media because of the accompanying silicon phase, which is attacked by alkalis [207]. 

SiSiC and, especially SSiC, are displacing the chemically less-resistant tungsten carbide (hard metal) and the thermal-shock-sensitive aluminum oxide in modem mechanical seals, where they are used in the form of slide rings. The excellent wear resistance of sintered SiC, combined with its excellent chemical resistance and outstanding tribological characteristics, ensure that mechanical seals made from this material last longer, which in turn results in much-reduced maintenance and production costs for pump-dependent processes in the chemical industry [564]. 

---