CHARACTERISATION OF MICROMECHANICALAND TRIBOLOGICAL PROPERTIES OF TITANIUM GRADE 2AFTER CYCLIC OXIDATION

Abstract

This paper presents the characterisation of micromechanical and tribological properties of titanium Grade2 before and after cyclic oxidation. The oxidation process was carried out at temperatures of 600C, 650Cand 700C in 4 and 12 cycles. Microscopic studies showed that oxide particle size increased with increasingoxidation temperature and the number of cycles. Titanium Grade 2 showed up to 3 times higher hardnessafter cyclic oxidation. The highest hardness (8.4 GPa) was obtained after 12 cycles of titanium oxidation at650C. Tribological tests were conducted in pairs with different materials (Al2O3, ZrO2, bearing steel 100Cr6).The presence of oxide layers obtained on the titanium surface resulted in a significant reduction in specificwear rate. Titanium Grade 2 showed the best resistance to sliding wear after cyclic oxidation at 600C duringsliding interaction with ZrO2 and 100Cr6 balls (unmeasurable wear under assumed test conditions). In theother test variants, the reduction in wear ranged from 37 to 96%.