Dry sliding behaviors and friction surface characterization of Ti3Al0.8Si0.2Sn0.2C2 solid solution against S45C steel

Abstract

Tribological performance of Ti3Al0.8Si0.2Sn0.2C2 solid solution sliding against S45C steel disk was investigated using a block-on-disk type tester at sliding speeds of 5–30 m/s under normal loads of 20–80 N. Ti3Al0.8Si0.2Sn0.2C2 exhibited a friction coefficient of 0.17–0.53 during the sliding process. It was shown that the wear rate decreased linearly as normal loads increasing from 20 to 80 N at 5 m/s, while the wear rates increased faintly in the range of 1.78–5.6 × 10−6 mm3/Nm with an increase in normal load when at other sliding speeds of 10 m/s, 20 m/s and 30 m/s. Both the friction coefficient and wear rate were found closely related to the tribo-oxidation induced tribofilm. Friction surface morphology and cross-section analyses revealed the tribofilm coverage played an effective performance, and the percentage of that was confirmed to increase with the sliding speed and normal load increasing. Phase composition and chemical states analyses of frictional surface showed that the tribofilm formed was a combination of TiO2, Al2O3, SnO2, SiO2, and Fe2O3 mixtures. Microstructure and physical state of the wear debris were also investigated for deeply understanding the contribution of the tribofilm.