Damage behavior of orthopedic titanium alloys with martensitic microstructure during sliding wear in physiological solution

Abstract

Wear damage behavior of new orthopedic Ti-13Nb-13Zr (mass %) alloy with martensitic microstructures developed by different thermo-mechanical treatments were examined during sliding in simulated physiological solution. The results obtained for this alloy processed by cold and hot rolling were compared with that of the standard Ti-6Al-4 V (mass %) alloy heat-treated to produce martensitic microstructure. The block-on-disk sliding friction and wear tests were conducted in Ringer’s solution. The friction coefficient, wear rate, and wear damage mechanisms were determined over a range of normal loads (20–60 N) and linear sliding speeds (0.26–1.0 m/s). The surface damage morphology revealed the presence of corrosive, abrasive, and adhesive wear in all investigated materials. The friction and wear properties were found to be dependent on the predominant wear damage mechanism and applied load/sliding speed combination. In the case of a Ti-13Nb-13Zr alloy, the adhesive wear contributes to the higher wear rate and better friction behavior. This cold-rolled alloy, having a martensitic microstructure with the lowest hardness, shows the lowest friction coefficient values due to high material transfer from the alloy surface. The lowest friction resistance is observed for the Ti-6Al-4 V alloy with the highest hardness since the dominant wear damage mechanism is abrasion resulting in the low wear rate and material transfer.