Tribology of tib coated TI and nanostructured TIB materials

In the present study, pin-on-disk wear testing was used to evaluate the tribological performance of TiB coated Ti-6A1-4V alloy and nanostructured TiB. The TiB coated Ti-6A1-4V was tested against alumina as a reference material with the result that the TiB coated Ti-6A1-4V samples performed much better. The ball bearings used as the pin samples had 40 times less volumetric wear than the alumina. The wear tracks on the alumina disk created by the TiB coated balls were also less deep and the alumina less affected when compared to the wear tracks created by the alumina balls. The friction of the TiB coated balls against the alumina disk was slightly less than that of the alumina balls against the alumina disk. The difference in wear performance and COF was attributed to the wear mechanisms of the two materials. The nanostructured TiB was examined under lubricated and dry conditions and compared against Si3N4 as a reference material. Under lubricated conditions the nanostructured TiB balls and Si3N4 balls performed similarly. The volumetric wear of both materials was about the same, as was the average COF. Under dry conditions, the nanostructured TiB had 2.5 times less volumetric wear than Si3N4 and had a slightly lower average COF. This was also attributed to the different wear mechanisms of the two materials.