In this work, an in-situ XPS analysis test combined self-designed high precision fretting wear tester was carried out to study the fretting wear behavior and the resulting tribo-oxidation of thermal-oxidation film on Ti6Al4V titanium alloy under the varied working atmosphere. The fretting-induced tribo-oxidation under the air and vacuum (4 × 10-3 Pa) environment was analyzed and its response on the resulting fretting wear resistance and damage mechanism was discussed. Results show that the working environment plays a significant role in the formation of tribo-oxidation and then determining the fretting wear resistance. Thermal-oxidation film in the vacuum atmosphere shows a better fretting wear resistance than that in the air atmosphere for all fretting regimes, except for partial slip regime (PSR) where there is an equivalent fretting wear resistance. Compared with the substrate Ti6Al4V titanium alloy, the thermal-oxidation film in the vacuum atmosphere performs a good protection for titanium alloy, especially for slip regime (SR), but not applied for air atmosphere.

An experimental investigation was conducted to study the fretting wear behavior of low alloyed construction steel in the tempered fully martensitic state. The resulting damage mechanism and the resistance to fretting wear of martensitic steels subjected to different tempering temperature was evaluated and compared with the virgin (un-tempered) martensitic steel under the different loading conditions. The results show that the friction coefficient increases with the increase of the tempering temperature for all the applied loads. The fretting wear resistance mainly depends on the tempering temperature. Compared to the virgin (un-tempered) full martensite, most of the tempered martensites have better fretting wear resistance, in which the tempered martensitic (TM) steel of 200° due to a good balance of strength and ductility has a super fretting wear resistance for all loading conditions. In addition, the correlation of fretting wear resistance with the initial hardness was discussed.