Wide-temperature-range tribological properties of Cu-Ni-Al films with multiple oxidation states

High-temperature (HT) apparatus suffer from galling and seizure of contact interface, for which a wear-resistant film is helpful but challenging to design. In this work, the Cu-Ni-Al films prepared by magnetron sputtering provide effective wear-resistant protection for Ni-based superalloy over room temperature (RT) to 800 degrees C, decreasing the coefficient of friction by 45 %, 30 %, 15 % and wear rate by 97 %, 65 %, 62 % at RT, 400 degrees C, 600 degrees C, respectively, and exhibiting especially low wear rate 1.88 x 10(-5)mm(3)N(-1)m(-1) at 800 degrees C. Layered structure with multiple oxidation states formed during friction is the crucial, with the Cu2O-rich layer and the CuO layer serving lubrication at RT and HT, respectively. The FCC + L12 structure ensures the high-temperature carrying capacity and film-substrate adhesion. AFM investigation exhibits the microscale tribological behavior is relevance with Ni + Al content. This work provides a novel strategy for the design and preparation of wide- temperature-range wear-resistant film.