调制比对磁控溅射法生长DLC/WS_x多层膜微结构和力学性能的影响

Effect of modulation ratio on microstructure and mechanical properties of DLC/WS_x multilayer films by magnetron sputtering

采用磁控溅射法在200℃Si(100)基体上交替沉积WS_x和类金刚石碳膜(DLC)制备不同调制比的DLC/WS_x多层膜(周期为10 nm)。利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、X射线光电子谱(XPS)等手段分析调制比对多层膜成分、微观结构及界面的影响。利用薄膜应力测试仪、纳米压痕仪、涂层附着力划痕仪和球盘式摩擦磨损试验机等测试多层膜的力学性能及大气中的摩擦磨损性能。结果表明:DLC/WS_x多层膜结构致密而平整,界面强化效应明显,膜中WS_x均为非晶结构。随着调制比增大,多层膜的n(S)/n(W)由0.77增大至1.08,硬度先降低后升高,膜内压应力逐渐减小,结合力先增大后减小,摩擦因数由0.307降至0.171,磨损率逐渐上升。调制比为1:39的多层膜性能最优,硬度可达11.4 GPa,磨损率低至1.17×10^(-15) m^3·N^(-1)·m^(-1),显著优于纯WS_x薄膜的。

The DLC/WSx multilayer films with various modulation ratios and modulation period of 10 nm were layer-by-layer deposited on Si（100） substrates by magnetron sputtering method at 200 ℃. The effects of modulation ratio on the chemical composition, microstxucture and interface of the films were characterized by means of scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS）, X-ray differactometry （XRD） and X-ray photoelectron spectroscopy （XPS）. The mechanical properties and txibological properties in atmosphere of the films were evaluated by residual stress tester, noao-indentation tester, scratch tester and ball-on-disc txibotester. The results show that DLC/WSx multilayers axe compact and smooth, the strengthening of interfacial effect is remarkable and WSx phase is defined as amorphous structure. As the modulation ratio increasing, the molar ratio of S and W increases from O.77 to 1.08, the hardness decreases first and then increases while the compressive stress decreases in the film gradually, the adhesion to substxate increases first and then decreases, the friction coefficient decreases from 0.307 to 0.171, and the wear rate increases. Compared with pure WSx film, DLC/WSx multilayer films have much better mechanical properties, and the film with modulation ratio of 1：39 has the best performance, its hardness is 11.4 GPa and its wear rate is of 1.17×10^15m3·N^-1·m^-1.