The nonprotective tribolayers of the titanium alloy were modified into additives-containing tribolayers through an artificial addition of multilayer graphene (MLG), Fe2O3 nanomaterials, or their mixtures with various proportions on the titanium alloy/steel sliding interface. The sustainability of the modified tribolayers under a high load was evaluated by the critical sliding distance for a mild-to-severe wear transition. The modified tribolayers were found to significantly improve or deteriorate tribological performance of the titanium alloy, which was decided by their ingredients. The pure MLG- or Fe2O3-containing tribolayers, because of their lacking load-bearing or lubricant capacity, presented poor sustainability and readily lost protection to cause high wear loss or frictional coefficient. However, for the addition of various mixtures of MLG and Fe2O3, the modified tribolayers possessed a double-layer structure consisting of friction-reducing MLG- and wear-resistant Fe2O3-predominated layers. They presented a sustainable protection, thus remarkably improving the tribological performance of the titanium alloy.
Tribological performance of surface engineered low-cost beta titanium alloy
