调制比对多层DLC薄膜性能的影响

Effect of Constant Modulation Ratios on the Performance of Multilayer DLC Films

针对DLC薄膜内应力大,膜基结合强度较差的问题。本文通过磁过滤真空阴极电弧设备,沉积不同偏压下的单层DLC薄膜,并以此为基础控制沉积多层DLC薄膜时各个阶段的偏压,镀制不同调制比下三层结构的DLC薄膜,最终使用纳米压痕划痕仪测试薄膜硬度、弹性模量和膜基结合强度,探讨了不同调制比对DLC薄膜机械性能的影响。实验结果表明:多层DLC薄膜硬度、弹性模量和膜基结合强度明显优于单层DLC薄膜。当多层DLC薄膜的调制比为1∶1∶8时薄膜硬度达到最大值70.14 GPa,薄膜弹性模量达到最大值794.8 GPa;当多层DLC薄膜的调制比为2∶2∶6时薄膜膜基结合强度较好,在最大划痕载荷25 mN的条件下,划痕的位移深度仅为57.3 nm,且薄膜硬度平均可达66.7 GPa,具有较好的综合性能。

The paper aims to solve the problems of large internal stress and poor bonding strength that Diamond like carbon(DLC)films have.Single layer DLC films at different biases were deposited by using the magnetic filtered cathodic vacuum arc equipment,on the basis of which the bias at each deposition stage of multi layer DLC films was controlled and then three layer structured DLC films with different modulation ratios were deposited.Finally,the effects of different modulation ratios on the mechanical properties of DLC films were evaluated according to the hardness,modulus of elasticity and bonding strength of DLC films measured by a nanoindentation/scratch tester.Results show that the hardness,modulus of elasticity and bonding strength of multi layer DLC films are superior to those of single layer DLC films.When the modulation ratio is 1∶1∶8,the hardness and elastic modulus reach the maximum,70.14 GPa and 794.8 GPa respectively;When the modulation ratio is 2∶2∶6,the film base has better bonding strength.When the maximum scratch load is 25 mN,the displacement depth of the scratch is only 57.3 nm,and the average film hardness is up to 66.7 GPa,indicating that the film has better general properties.