不同过渡层对DLC薄膜力学性能和摩擦学性能的影响

Influences of Different Interlayers on Mechanical and Tribological Properties of DLC Films

薄膜与基体间的界面结合性能是决定薄膜性能发挥的关键要素。针对类金刚石薄膜(DLC)在硬质合金上结合力差的问题,采用线性阳极离子束复合磁控溅射技术在硬质合金YG8基体上设计制备了单层W过渡层、WC过渡层、双层W过渡层和三层W过渡层4种不同W过渡层的DLC薄膜,探讨了不同过渡层对DLC薄膜力学和摩擦学性能的影响。结果表明:不同过渡层结构的DLC薄膜结构致密,界面柱状生长随着层数增加及过渡层厚度的降低而打断,有利于改善薄膜的韧性。当为三层W过渡层时,DLC薄膜的断裂韧性达到最大值6.44 MPa·m1/2;与单层W过渡层相比,薄膜硬度有小幅下降,但薄膜内应力降低了55%,且膜/基匹配性更佳,结合强度高达85N,此时薄膜具有较低的摩擦因数和磨损率,表现出比较优异的抗磨减摩性能。

Adhesion between the film and the substrate is a key factor to determine the performance of the films. Due to the low adhesion of diamond-like carbon （DLC） film on cemented carbide, the DLC films with different W interlayer （single W layer, single WC layer, W bilayer, and W trilayer） were deposited on cemented carbide YG8 substrate by a novel linear ion beam source composited with a DC magnetron sputtering process. The mechanical and tribological prop- erties of DLC films were evaluated. The results show that the DLC films with different W interlayers are dense, and the interracial columnar structure with the increased layers is interrupted, which is conducive to improve the toughness of DLC films. For the DLC film with W trilayer, its the biggest toughness is 6.44 MPa·m1/2. The hardness decreases, howerver, the residual stress can be reduced by 55% compared to the film with single W layer and the adhesion strength reaches to 85 N. Additionally, this film has lower friction coefficient and wear rate, which exhibits excellent anti-wear and anti-friction properties.