Comparison of the friction and wear properties of titanium and oxidised titanium in dry sliding against sintered high speed steel HS18-0-1 and against C45 carbon steel

The paper presents the results of conformal pin-on-disc tribological tests concerning the hard oxidised zone, α-Ti(O), created at the surface of a titanium specimens sliding against the sintered and hardened up to 850 HV30, Grade T1 high speed steel (HS18-0-1) counterspecimens. Comparison with the results obtained for the tests performed against hardened up to 620 HV30 C45 carbon steel counterspecimens has been done. Testing was carried out at room temperature and at unlubricated conditions. After tests the structures and compositions of the worn surfaces and wear debris were a subject of LOM, SEM observations and X-ray microanalyses. In comparison with the baseline—the Ti/T1 HSS couple, the wear resistance of the α-Ti(O)/T1 HSS couple appeared to be poorer with the factor of 1.4–2.3. Strong adhesion between mating bodies and abrasive action of the hard α-Ti(O) wear particles were found responsible for high intensity of wear of the oxidised titanium. In opposite to that, the wear resistance of the α-Ti(O)/C45 carbon steel couple appeared to be better with the factor of 28–68. Fine powder of iron oxides between mating bodies has been found playing protective role.