Effect of Surface Modification on Tribological Properties of VT22 and Ti-5553 Titanium Alloys

Tribological properties of VT22 and Ti-5553 titanium alloys are improved due to the chemical-thermal treatment of their surfaces and the application of a wear-resistant titanium nitride coating. The tribological properties were compared for samples without additional surface treatment, with surface modification by nitriding, with the titanium nitride coating, as well as with a two-stage treatment of sample surfaces, including primary nitriding of the surface followed by the application of a titanium nitride coating on it. It was found that low wear resistance is observed in titanium samples without coatings, while the wear resistance of samples with a nitrided surface layer increases for both types of tested alloys. Minimal wear occurs for the samples with two-stage formation of a titanium nitride coating while on samples without an intermediate nitrided sublayer, when tested with a ceramic ball, delamination of the coating is observed; the formation of the sublayer prevents this type of destruction.