Some studies of wear and lubrication

Abstract

Studies of wear and lubrication carried out at the Aldermaston laboratories of Associated Electrical Industries Limited are described. Optical, electron optical, radioactive tracer and metallographic techniques have been used to reveal the various stages of wear processes. Two distinct types of wear have been found; severe wear due to metallic welding and mild wear in which the debris is more finely divided and mainly non-metallic. In both types of wear transfer of material from one rubbing surface to the other can take place but, particularly with mild wear, the wear process is not unique but varies with the combination of materials and the rubbing conditions. The lubrication of nominal line contacts such as occur in gears and roller bearings has been shown to be essentially hydrodynamic and the thickness of the oil film has been measured. At practical loads the thickness is independent of load but very dependent upon the temperature of the surfaces. The experiments have been made in disc machines and the surface failures and sub surface deformations which can occur before the discs run in to a state of complete hydrodynamic ubrication have also been studied.