Page 169 - 《摩擦学学报》2021年第6期

954 摩 擦 学 学 报 第 41 卷

alloy by PECVD method. The microstructure, mechanical properties and the effect on the tribological properties for the
as-prepared DLC films sliding against different mating ceramic balls and metal balls were investigated. The chemical
composition and microstructure of the as-prepared DLC film were analyzed by Raman spectrum, scanning electron
microscopy, energy dispersive spectrometer. The hardness and elastic modulus of the film were tested by
nanoindentation. The bonding strength between the film and the substrate was measured by a scratch tester. The dry
tribological performances of DLC film sliding against different ceramic and metal balls under air conditions were
evaluated using a ball-on-disc wear tester. The results showed that the surface morphology of the graded DLC film was
relatively smooth and uniform, and the film was well adhered to the substrate. The mechanical properties of deposited
DLC film were excellent in this work. Eight tribo-pairs exhibited different friction and wear behaviors, and the
ceramic/DLC pairs showed lower coefficient of friction and slighter wear of mating balls than the metal/DLC pairs,
which were related to the properties of mating materials and action mechanism between the mating material and the
DLC films. The possible friction and wear mechanisms of each tribo-pairs were further discussed. It suggested that for
the ceramics/DLC tribo-pairs, it was easy to form stable carbonaceous transfer film on the ceramic balls due to high
hardness and good wear resistance of the ceramic balls. SiC/DLC, Si 3 N 4 /DLC and ZrO 2 /DLC exhibited mainly mild
abrasive and adhesive wear while Al 2 O 3 /DLC revealed being damaged and peeled off but the friction coefficient was
still at lower level because of the higher carbon content on the surface of the Al 2 O 3 ball. And comparing the metals/DLC
tribo-pairs with the ceramics/DLC tribo-pairs, it was difficult to maintain stable carbonaceous transfer film on the metal
balls due to lower hardness of the metal balls, resulting in higher friction coefficient. Al/DLC exhibited mainly severe
abrasive wear while brass/DLC, 304SS/DLC and GCr15/DLC revealed mild abrasive or adhesive wear. It also suggested
that SiC/DLC, ZrO 2 /DLC, 304SS /DLC and GCr15/DLC can be reasonable tribo-pairs because of relatively lower
friction coefficients and wear rates of the DLC films and the small wear scars. Hertzian contact analysis showed that the
variation trend of average friction coefficient and calculated contact radius was consistent in the ceramic/DLC tribo-pairs
except ZrO 2 /DLC, but this phenomenon was not found in metals /DLC tribo-pairs.
Key words: titanium alloy; DLC film; mating balls; friction and wear; Hertzian contact analysis

钛合金具有强度高、密度低、耐腐蚀和良好的抗 擦学行为，结果表明对偶材料与碳之间的附着力对DLC
[20]
疲劳性能等优点，广泛应用于机械、航空和生物医学 薄膜的真空摩擦学行为有较大影响；Wu等 研究了304
等各个领域，但其较差的摩擦学性能阻碍了其在苛刻 不锈钢基材上制备的DLC薄膜在空气和氦气里与不同

工况条件下的应用 [1-3] ，通常采用涂层、热氧化和化学 陶瓷对偶材料干摩擦时的摩擦学性能，发现其摩擦学
热处理等表面处理方法改善其力学性能和摩擦学性 性能受气体环境和对偶配副材料的影响，在空气中WC球
能 [4-6] ，其中真空镀膜作为涂层中一种有效的表面改性 和ZrO 球摩擦副分别具有最低的摩擦系数和磨损率.
2
方法，通过在超高真空下对基材表面进行功能薄膜的 以往研究对偶材料对DLC薄膜摩擦学性能的影
沉积从而改善基材表面性能和摩擦学性能. 响中，采用的基材、制备工艺和试验环境各不相同，然
类金刚石薄膜(DLC)是1种典型的真空镀膜，具有 而不同的基材和制备工艺对薄膜的结构、承载能力和
高硬度、优异的摩擦学性能、良好的化学惰性和生物 结合力方面的影响不同，从而与相同的材料配副的摩
相容性等优点 [7-9] . DLC薄膜的摩擦学性能受基底材 擦磨损性能也不同. 等离子体增强化学气相沉积法
料、制备工艺和使用条件等因素的影响，在实际应用 (PECVD)是一种真空镀膜方法，具有工艺简单、沉积
中与不同对偶材料组成摩擦副时也受到对偶材料的 温度低和成膜质量好等优点，可以在常温下制备出光
[16]
影响 [10-15] . 王等 发现配副材料对钢基材上氟化DLC 滑致密的DLC薄膜. 目前钛合金上制备DLC薄膜已有
[17]
薄膜的摩擦学行为有不同的影响机制；Li等 研究发 大量研究，但利用PECVD工艺在钛合金上制备梯度DLC
现DLC薄膜在潮湿的N 中与Si N 、Al O 和钢球配副 薄膜并用于探索多种金属对偶球和陶瓷对偶球对其
4
3
3
2
2
[18]
的摩擦磨损行为取决于摩擦诱导化学作用；郑等 以 摩擦学性能影响的研究还尚未发现. 基于此，本文作
第一性原理研究了真空和CO 环境对于DLC与Al和 者在钛合金基材上制备梯度DLC薄膜并研究其在常
2
ZrO 配副摩擦性能的影响，发现不同环境中对偶球与 温空气中与4种陶瓷球和4种金属球配副的干摩擦磨
2
薄膜形成不同的化学键是影响摩擦性能的关键；Cui 损行为，并对其摩擦磨损机理进行分析，为DLC薄膜
[19]
等 研究了含氢DLC薄膜与不同陶瓷球配副的真空摩 实际应用提供依据.