INFLUENCE OF THE MICROSTRUCTURE OF CERAMIC MATERIALS ON THEIR WEAR BEHAVIOR IN MECHANICAL SEALS

Ceramic materials such as aluminium oxide and silicon carbide are regu larly used as one of the counterfaces to oppose carbon graphite in a m echanical seal. Under nominally identical test conditions, the same ca rbon graphite face can show high wear rates against a material from on e supplier but a significantly lower wear rate on a similar material f rom another. The general descriptions of aluminium oxide and silicon c arbide can cover significant differences in properties between materia ls from various suppliers. Ceramic counterfaces from several manufactu rers have been examined, after testing under similar conditions, in or der to understand the microstructural factors that influence the wear of the carbon graphite and hence the life of the mechanical seal. Ther e is evidence to suggest that the wear resistance of the system depend s on the gram size distribution, the integrity of the grain bonding an d the presence of additional phases.