WSCF coatings tested under various environmental conditions: A multivariate tribological analysis

This study examines the influence of carbon (C) and fluorine (F) on the tribological and mechanical properties of WSCF coatings. WSCF-coated substrates were prepared with varying levels of C (10.4 to 18.7 at%) and F (5.3 to 9.3 at%) using DC reactive magnetron sputtering. Tribological performance was evaluated at 25 °C and 200 °C in dry and lubricated conditions. Alloying led to thicker, more amorphous, denser, and smoother coatings. An exceptional coefficient of friction (COF) as low as 0.008 was observed for WSCF2 (15.4 at% C and 9.3 at% F). Principal component analysis (PCA) revealed high F-doped coating in WSCF2 demonstrated improved tribological performance, resulting in a 38 % reduction in COF at 25 °C and dry conditions. • C and F alloying to WS₂ coatings results in smooth and amorphous coatings. • C and F enhance tribological performance and steel adhesion in WS₂ coatings. • Optimal tribological performance is at 15.4 % C, 9.3 % F, with 38 % reduced friction. • WSCF2 coatings exhibit exceptional low friction of 0.008 under dry conditions. • PCA reveals the complex interplay of alloying, environment, and coating properties.