Tribological performance of boronized Ti6Al4V alloy against Si 3N4 ball

Abstract

In this study, the wear performance of boronized Ti6Al4V alloy has been examined. Boronizing has been carried out in commercial Ekabor II boronizing powder at 1100°C for 2.5 h. Characterization of the boronized surface was made by microscopic examinations, hardness measurements and X-ray diffraction analysis. Wear tests were performed under unlubricated and lubricated conditions at room temperature on a reciprocating wear tester by rubbing Si <inf>3</inf>N<inf>4</inf> balls. Upon boronizing, uniform and compact surface layer having thickness of about 10 um has been formed, which resulted in a remarkable increase in surface hardness. This surface layer having hardness of 2700 HV was composed of TiB and TiB<inf>2</inf> phases. When compared to the untreated alloy, the wear rate of boronized Ti6Al4V alloys was almost negligible. Under both unlubricated and lubricated testing conditions boronized alloy exhibited lower friction coefficient than untreated alloy. © 2008 Elsevier B.V., All rights reserved.