Effects of Nb Content and Heat Treatment on Fretting Wear Behavior of Ti-Nb Alloys

Abstract

Ti-Nb alloys in deionized water and Hanks' balanced salt solution were investigated at 310K using a ball-on-disc type frictional test machine with a ZrO2 ball counterface. In this study, besides the fretting wear behavior of Ti-Nb alloys was investigated, the relationship between the microstructure and mechanical properties of the Nb-added Ti alloy was investigated, and the relationship between the composition and hardness on the fretting wear of the alloy will be clarified from the results of the wear volume and surface analysis of wear track. The results obtained from the frictional test indicate that the dynamic coefficient of friction converged to a constant value with time variation. Also, wear volume in HBSS was smaller than in water, and wear volume of heat-treated became smaller than As-Rolled. Microstructural observations suggest the scars of adhesive wear were observed. Comparing each morphology, the ratio of the peeling part was more significant in Ti-Nb alloys, which have α+β than in Ti-Nb alloys, which have only β. Moreover, the results of Open circuit potentiometry indicate that the corrosion potential difference increased with wear. This is most likely due to the passive film was damaged. Besides, the corrosion potential difference of β-Ti-Nb alloy heat-treated with HBSS is small. It is assumed that there is an influence of HBSS besides the fine structure.