Tribological performance of electroless Ni alloy plated spur gears in high vacuum

Spur gear test was carried out under non-lubricating condition in high vacuum of the order of 10^-4 Pa at room temperature to investigate the wear and friction performances of electroless Ni alloy platings. Three kinds of electroless Ni alloy platings; electroless Ni-P alloy plating, electroless Ni-B alloy plating and electroless Ni-P-B alloy plating, and two kinds of composite platings; electroless Ni-P alloy plating with PTFE particles and electroless Ni-P alloy plating with BN particles, were employed. The influences of the composition and the dispersed self-lubricated particles in the electroless Ni alloy platings on the tribological performance were examined. In addition the gear test results were compared with the roller test results obtained under about the same maximum Hertzian pressure.