IMPROVING THE FRETTING WEAR-RESISTANCE OF TITANIUM-ALLOY BY LASER-BEAM QUENCHING

The effects of amplitudes and normal loads on the fretting wear of tit anium alloy (TC11) were experimentally investigated on a SRV fretting wear test machine in air, at room temperature and without lubrication. The wear depths were measured by a profilometer, the worn areas were observed and measured by an optical microscopy, and the micro-topograp hies of worn scars were studied by scanning electron microscopy (SEM). The tests and observations state clearly that the fretting wear volum e (FWV) is heavily influenced by the sliding amplitude (SA) and load. In this experiment, if the SA is greater than 60 mu m at a Hertzian co ntact stress of 105 MPa, the FWV is much greater, and SEM indicates th at the wear mechanism is the combination of adhesive and contact fatig ue for the above test conditions. in contrast, if the SA is smaller, t he FWV is smaller too, and SEM suggests that the major wear mechanism is contact fatigue. The experiments also reveal that laser beam quench ing greatly improves the fretting wear resistance of titanium alloy, e specially at heavy load and large amplitude. (C) 1997 Elsevier Science S.A.