Preparation and Tribological Properties of Face Centered Cubic TiB Coatings on the Ti6Al4V Alloy

To improve wear resistance of Ti6Al4V alloys, a face- centered cubic (FCC) TiB coating was fabricated on the surface using pack boriding. The coatings were mainly composed of an outer TiB layer and inner slight TiB whisker. The average surface microhardness values of the coatings prepared at 900-1100 degrees C were 796-1719 HV0.05, which are significantly higher than that of the substrate. The cross-sectional microhardness exhibited a gradient change, which was conducive to the improvement of tribological properties from the coating to the substrate. The wear mechanism of TiB coatings obtained at different temperatures is discussed. The wear rate of the boride coatings prepared at 1100 degrees C against a Si3N4 ball was 1/3rd that of the Ti6Al4V alloy substrate. The coatings exhibited good wear resistance owing to the good anti-wear resistances of the hard TiB phase.