调制周期对纳米多层类石墨薄膜力学性能及摩擦学性能的影响

Influence of Modulation Period on the Mechanical and Tribological Properties of Nano-multilayer Graphite-like Carbon Films

采用等离子增强多靶磁控溅射系统在溅射沉积类石墨(Graphite-like carbon,GLC)薄膜过程中交替掺杂金属W制备了6种纯GLC子层和W-GLC子层交替堆垛的纳米多层GLC薄膜.薄膜调制周期分别为300 nm、180 nm、90 nm、40 nm、15nm以及8nm共6种.研究了调制周期对薄膜力学性能和摩擦学性能的影响.结果表明:各纳米多层GLC薄膜均具有良好的力学性能与摩擦学性能,且随着调制周期的减小,薄膜的力学性能与摩擦学性能均大幅提高,并表现出显著的协同效应.纳米多层GLC薄膜中WC或W2C纳米晶的弥散强化效应和纳米多层膜的界面效应是薄膜具有优异力学性能的主要原因,而薄膜在摩擦对偶表面形成的厚实致密的富碳转移膜又确保了薄膜具有良好的摩擦学性能.当调制周期减小至8 nm时,薄膜的硬度高达35.13 GPa,结合强度为45.28 N,H/E为0.109 5,H3/E2为0.375,且在“100 r/min,12N”条件下连续摩擦480 min,平均摩擦因数仅为0.002,磨损率低至9.0× 10-18 m3/(N·m),综合性能极为优异.

Six kinds of nano-multilayer graphite-like carbon（GLC） films with different modulation periods of 300 nm, 180 nm, 90 nm, 15 nm and 8 nm are deposited by a plasma enhanced multi targets magnetron sputtering system. The influence of modulation period of pure GLC film and W-GLC film on the mechanical and tribological properties of the films is analyzed. The test results show that all the deposited nano-multilayer GLC films present good mechanical and tribological properties, which improve with the decrease of modulation period and show remarkable synergistic effect. The excellent mechanical properties of the films can be attributed to the dispersion strengthening effect of WC or W2C nanocrystals and the interfacial effect of multilayers, while the formation of thick and dense transfer film guarantee the film’s good tribological properties. When the modulation period reduces to 8 nm, the film hardness reaches 35.13 GPa, and the corresponding adhesive strength is 45.28 N,H/E is 0.109 5,H3/E2 is 0.375, and the film has the lowest average friction coefficient of 0.002 and wear rate of 9.0×10-18m3/（N·m） when tested at a load of 12 N and a sliding rate of 100 r/mim for 480 minutes, which shows excellent comprehensive performance.