基体对类金刚石薄膜力学性能和摩擦学行为的作用

论文总字数：29114字

摘 要

Abstract ………………………………………………………………………… Ⅱ

1. 绪论 ………………………………………………………………………1

1.1 引言 …………………………………………………………………1

1.2 类金刚石薄膜的结构和分类 ……………………………………1

1.3 类金刚石薄膜的制备方法 ……………………………………………… 2

1.3.1 磁控溅射 ……………………………………………… ………3

1.3.2 离子束沉积成膜 ………………………………………………3

1.3.3 脉冲激光沉积 ………………………………………………4

1.3.4 等离子体增强化学气相沉积 …………………………………4

1.3.5 真空阴极电弧沉积 ……………………………………………4

1.4 类金刚石薄膜的性能和应用 ……………………………………………5

1.3.1 类金刚石薄膜的机械性能和应用 ……………… ……………5

1.3.2类金刚石薄膜的电学性能和应用 ………………………………6

1.3.3类金刚石薄膜的光学性能和应用 ………………………………6

1.3.4类金刚石薄膜的摩擦学性能和应用 …………………………6

1.3.5类金刚石薄膜的声学性能和应用 ………………………………6

1.3.5类金刚石薄膜的医学应用 ………………………………………6

1.5 研究内容和目标 …………………………………………………………6

1. 实验方案及内容 ……………………………………………………………7

2.1 实验方案 …………………………………………………………………7

2.2 样品预处理 ……………………………………………………………7

2.3 薄膜制备 …………………………………………………………………7

2.3.1 磁控溅射 设备及原理……………………………………………7

2.3.2 实验流程及参数设置 ……………………………………………8

2.4 薄膜的结构、成分及形貌表征 ………………………………………10

2.4.1 SEM ……………… ……………………………………………10

2.4.2 AFM ………………………………………………………………10

2.4.3 XRD ………………………………………………………………11

2.4.4 Raman光谱分析 ………………………………………………11

2.5 薄膜的机械性能评价 ……………………………………………………12

2.5.1 显微硬度 ……………………………………………… ………12

2.5.2 纳米压痕 …………………………………………………………12

2.5.3 结合力分析 ……………………………………………………13

2.5.4 摩擦磨损性能评价 …………………………………………13

1. 薄膜的制备及结构形貌表征 ………………………………………………15

3.1 薄膜形貌表征 ………………………………………………………15

3.1.1 SEM …………………………………………………… ………15

3.1.2 AFM ……………………………………………………………16

3.2 薄膜结构表征 ………………………………………………………17

3.2.1 XRD …………………………………………………… ………17

3.2.2 Raman …………………………………………………………18

3.3 本章小结 …………………………………………………………………20

1. 薄膜的机械性能研究 ………………………………………………………21

4.1 显微硬度 …………………………………………………………………21

4.1.1 基体与薄膜承载力测试 …………………………… ………21

4.1.2 不同基体的承载失效形式………………………………… ……22

4.1.3 断裂韧性 ……………………………………………… ………24

4.2 纳米压痕 …………………………………………………………………25

4.3 结合力 ……………………………………………………………………26

4.4 摩擦学性能评价 …………………………………………………………27

4.5 本章小结 …………………………………………………………………30

结论 …………………………………………………………………………………32

参考文献（References） ……………………………………………………………33

致谢 …………………………………………………………………………………35

摘 要

本文采用闭合场非平衡磁控溅射方法,制备了单晶硅Si、黄铜Cu和高速钢HSS等三种不同基体上的类金刚石薄膜。采用扫描电子显微镜、原子力显微镜观察薄膜的表面和截面微观形貌；通过拉曼光谱和X射线衍射表征DLC膜的结构。结果表明三种薄膜厚度约1.1微米，光滑平整，粗糙度4~6nm。薄膜具有非晶碳结构，具有明显的D峰和G峰，但峰强度比值不同，分析表明DLC/Si的sp³键比例最高，DLC/Cu最低。

采用维氏显微硬度计和纳米压痕仪分别表征材料承载力的和薄膜本征硬度；采用洛氏硬度计压入法评价了膜基结合力；采用摩擦磨损试验仪研究了材料的摩擦学性能。结果表明薄膜可以提高原始基体的承载能力，且DLC/Si的承载能力最佳，其次为DLC/HSS，DLC/Cu最差；DLC/Si在50g载荷即出现径向裂纹和周向裂纹，DLC/HSS和DLC/Cu由于塑性更好，只出现周向裂纹。计算结果表明DLC膜可以显著提高基体的断裂韧性。DLC膜具有高的本征硬度、弹性模量和硬弹比，DLC/Si最高，DLC/Cu最低。

摩擦磨损试验表明DLC膜可以显著降低材料的摩擦系数至0.15，具有良好的摩擦学性能。磨损类型主要是粘着磨损和磨粒磨损。

关键词: 类金刚石薄膜，磁控溅射，单晶硅，高速钢，黄铜，摩擦磨损

ABSTRACT

In this thesis, the diamond-like carbon films were prepared by closed field unbalanced magnetron sputtering on three different substrates: monocrystalline silicon, brass and high speed steel (HSS).

The structure of the thin films was investigated by X-ray diffraction and Raman spectroscopy. The microscopic morphology of the surface and section of the diamond-like films were characterized by scanning electron microscope and atomic force microscope. The results exhibited that the total thickness of the coating was about 1.1μm. The DLC films were smooth with little difference in roughness. The films had an amorphous structure and discrete G and D peaks were observed and films on different substrates had different I_D/I_G results, brass-substrate DLC had the highest I_D/I_G.

The load baring capacity and nano-hardness were measured respectively by standard micro-hardness tester and nano-indentation instrument, while the interfacial adhesion between thin films and substrates were investigated using Rockwell hardness tester. The films’ tribological properties in ambient air were determined by a pin-on-disk tribometer. The results showed that Si and Si-substrate DLC had the best load baring capacity with radial crack and brittle rupture, while the HSS and brass-substrate DLC’s capacity were worse with circumferential crack. Calculation results showed that DLC films improved the fracture toughness of silicon substrate. DLC films bare high hardness, modulus of elasticity. The hardness of Si-DLC was the highest and Cu-DLC the lowest, corresponding with Raman results, sp³ ratio. Finally, DLC films exhibited excellent friction and wear properties, showing lower friction coefficient. Adhesion wear and abrasive wear were the main wear mechanisms.

剩余内容已隐藏，请支付后下载全文，论文总字数：29114字