Dual motion fretting wear behaviors of titanium and its alloy in artificial saliva
(1. State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China;
2. Department of Stomatology, Aviation General Hospital, Beijing 100012, China;
3. Tribology Research Institute, Key Laboratory for Advanced Materials Technology of Ministry of Education,
Southwest Jiaotong University, Chengdu 610031, China)
2. Department of Stomatology, Aviation General Hospital, Beijing 100012, China;
3. Tribology Research Institute, Key Laboratory for Advanced Materials Technology of Ministry of Education,
Southwest Jiaotong University, Chengdu 610031, China)
Abstract: A dual motion combined by radial and tangential fretting was achieved on a modified hydraulic fretting wear test rig. The dual motion fretting tests of medical pure titanium (TA2) and Ti6Al7Nb alloy in artificial saliva were carried out under varied contact inclined angles (45° and 60°), and the maximum imposed load varied from 200 to 400 N at a constant loading speed of 6 mm/min. The effects of the cyclic vertical force and the inclined angle were investigated in detail. Dynamic analysis in combination with microscopic examinations shows that the wear scar and plastic deformation accumulation present a strong asymmetry. The Ti6Al7Nb has better wear resistance than TA2 in artificial saliva at the same test parameters, and with the increase of inclined angle and decrease of imposed load, the wear reduces accordingly. The wear mechanisms of pure titanium TA2 and Ti6Al7Nb alloy under the condition of dual motion fretting in artificial saliva are abrasive wear, oxidative wear and delamination.
Key words: titanium alloy; fretting wear; dual motion fretting; tangential fretting; radial fretting; wear mechanism