Popis: |
The effects of boron, carbon, nitrogen and oxygen ion implantation on the friction properties and wear behaviour of Ti6Al4V have been investigated under low and high contact stress conditions. With low contact stresses, ion implantation results in some increase in the incubation period for measurable wear mass loss. However, the effects are less than those produced by conventional surface alloying with oxygen and the subsequent steady state wear rates are not altered. The effects are attributed to an increase in the surface microhardness implantation by ion implantation rather than to a change in the wear mechanism, which remains predominantly abrasive. With high contact stresses, however, boron implantation increases the incubation period for measurable wear from a sliding distance of 10 m to a sliding distance of 90 m and is far more effective than other implant species and conventional surface treatments. There is again no change in the steady state wear rate or the wear mechanism although in this case the effect is clearly not attributable to an increase in the surface microhardness. |