material has proven to be very successful. Test rig experiments showed an almost triple specific load capability of the bearing system with a shaft sleeve made of SiC/SiC, sintered SiC as static bearing, and water at as lubricant. The specific load capacity of a bearing is usually given in W/mm2 and calculated as a product of the load (MPa), the surface speed of the bearing (m/s) and friction coefficient; it is equal to the power loss of the bearing system due to friction. This slide bearing concept, namely SiC/SiC shaft sleeve and SiC bearing, has been used since 1994 in applications such as in the boiler feedwater pumps of power stations, which pump several thousand cubic meters of hot water to a level of , and in tubular casing pumps for water works or seawater desalination plants, pumping up to to a level of around . This bearing system has been tested in pumps for liquid oxygen, for example in oxygen turbopumps for thrust engines of space rockets, with the following results. SiC and SiC/SiC are compatible with liquid oxygen. In an auto-ignition test according to the French standard NF 28-763, no auto-ignition was observed with powdered SiC/SiC in 20 bar pure oxygen at temperatures up to . Tests have shown that the friction coefficient is half, and wear one-fiftieth of standard metals used in this environment. A hydrostatic bearing system (see picture) has survived several hours at a speed up to 10,000 revolutions per minute, various loads, and 50 cycles of start/stop transients without any significant traces of wear. Other applications and developments Thrust control flaps for military jet engines Components for fusion and fission reactors Friction systems for various applications Nuclear applications heat treatment, high temperature, soldering fixtures References Further reading Ceramic materials Composite materials