Prospective use of chalcogenides in bearings with gas lubrication

The use of chalcogenides as antifriction coatings for gas flow bearings in the helium compressors of high temperature helium cooled reactors was evaluated during start and stop tests of the compressor rotors under dry and semidry friction conditions. Tests were conducted on lubricant films of molybdenum disulfide, tungsten disulfide, tungsten diselenide, and tantalum diselenide at fixed sliding speeds and pressures. Results are tabulated for operating pressure and temperature ranges, microhardness, wear, and coefficients of friction, and indicate that the diselenides of tantalum and tungsten possess the best lubricant properties. Studies on the thermal stability of the compounds in helium were conducted. Diffusion coatings of molybdenum disulfide were also assessed