Tribochemical Formation of Sulphide Tribofilms from a Ti–C–S Coating Sliding Against Different Counter Surfaces

摘要: Tribochemically active Ti–C–S coatings are nanocomposite containing a S-doped titanium carbide, from which S can be released in tribological contact. This work studies tribochemical reactions between coating and various counter surface materials, their effect on the performance. Tribological tests were performed ball-on-disc set-up, using balls of five different materials as sliding partners for coating: 100Cr6 steel, pure W, WC, 316-L steel Al2O3. For W balls, WS2 tribofilm was formed, leading to low friction (down µ = 0.06). Furthermore, increasing normal load found lead strong decrease earlier formation low-friction tribofilm. Similar MoS2 tribofilms were, however, not formed WC- Mo-containing balls. The performance when WC Al2O3 significantly worse than two It is suggested that this due sulphide Fe, analogous anti-seizure S-containing extreme pressure additives surfaces. activity coatings, with possibility release, thus beneficial only surfaces, but also Fe-based partners.