Adhesion Strength and Tribological Properties of Cr/Ag Nanoscaled Multilayer Films

The Cr/Ag nanoscaled multilayer films with different modulation periods were deposited by magnetron sputtering. The microstructure and composition of these films were analyzed using X-ray diffraction and high resolution transmission electron microscopy. The adhesive strength of the coating/substrate system and the tribological performance of Cr/Ag nanoscaled multilayer films, Cr/Ag double layer film and pure Ag film were comparatively studied using scratch tester and ball-on-disc tribometer in vacuum. The results indicate that the introduction of Cr layers can improve the adhesive strength of the coating/substrate system. Moreover, the interfaces with "accordant" crystal structure were prone to be formed between the Cr layer and Ag layer because of the very similarity of the lattice parameters of the Cr and Ag. Accordingly, the adhesive strength between the layers in multilayer films was also improved. As a result, the Cr/Ag nanoscale multilayer films showed better tribological performance than the pure Ag film and Cr/Ag double layer film under relatively high sliding speed and heave load conditions.