Effects of Sputtering Pressure on Tribological Properties of Vanadium Films on Aluminum Alloy by High Power Pulsed Magnetron Sputtering

Abstract:

Vanadium films were prepared on the surface of aluminum alloy using a high power pulsed magnetron sputtering (HPPMS) method. The influences of the sputtering pressure on the phase structure, surface morphology and tribological properties of vanadium films have been investigated. Results show that the vanadium phase in the vanadium films only grows along the (111) crystal under different pressures. The diffraction peaks increase with increasing the pressure and decrease if the pressure further increasing. The diffraction peak of V(111) is the strongest and the preferred orientation is the most obvious when the pressure is 0.5 Pa. Meanwhile the vanadium film has the smoothest surface with the surface roughness of only 0.267 nm. The samples demonstrate much lower friction coefficient compared with the substrate at room temperature. The sample treated at 0.5 Pa possesses the best tribological properties with the friction coefficient decreasing from 0.57 to 0.28, and there is no obvious spalling on the worn surface. The friction coefficients of vanadium films annealed at 200 and 300 °C is low and stable compared with the unannealed samples, which is attributed to the surface oxidation