Ceramics - Material for highly loaded sliding bearings

Conventional sintered silicon carbide is used in journal bearing of pumps for many years due to its high corrosive and wear resistance. Often the brittle failure of this material causes problems, though. Ceramic matrix composite (CMC) material based on carbon or silicon carbide fibres with high fracture toughness and elongation potential of 0,5 to 0,9 % is available now and is presented with its basic mechanical and tribological properties. Excellent results in tests of a journal bearing system using CMC shaft sleeves and conventional SSiC as bushing material are reported. Applications of journal bearings used in pumps using water up to 160 °C as lubricant, of bearings running under dry conditions at 1600 °C in space re-entry systems and of a journal bearing test up to 10,000 cpm with liquid oxygen (LOX) as lubricant are presented.