Achieving high toughness and wear resistance for hard TaN-Ag films actuated by Ag.

Ceramic-Ag films with enhanced mechanical and tribological properties have been widely researched. Transition metal nitrides (TMNs) films as hard ceramic material with doping Ag atoms commonly show a nano-composite structure and possess the combination of high hardness and toughness. Herein, the TaN film with incorporating few Ag atoms (1.2 at.%) presents FCC solid solution structure according to the HRTEM and XPS results, accompanied by grain refinement. From the XPS valence band and HRTEM, the increased metallic characters in electronic structure of TM-N bonds and the decreased grain size results in the enhanced mechanical properties. The TaN-Ag film with solid-solution structure possesses higher hardness (36.1 GPa) and toughness (K IC = 1.48 MPa*m1/2), combined with an improved wear resistance (wear rate: ∼1.9 × 10−6 mm3/N*m). In addition, a relatively lower coefficient of friction (0.18–0.23) is achieved for TaN-Ag films from the lubrication of AgTaO 3 activated by Ag atoms. • TaN-Ag film with doping 1.2 at.% Ag possess solid-solution structure. • TaN-Ag film with solute Ag shows enhanced metallic and strength character. • TaN-1.2 at.% Ag film obtains higher H (36.1 GPa), H/E (0.107) and H3/E2 (0.413 GPa). • Low wear rate of 1.9 × 10−6 mm3/N*m is obtained for TaN-1.2 at.% Ag film. • TaN-Ag films possess low Cof by the AgTaO 3 activated from self-oxidation of Ag. [ABSTRACT FROM AUTHOR]