For their mechanical properties of investigated specimen, they were conducted by means of nanoindentation technique, a novelly decussating-type hardness indentation, and the dry sliding wear tests。 Results from nanoindentation tests depicted that much higher hardness and Young’s modulus was obtained for the Ni-CeO2 coatings relative to that of pure nickel, but little lower than that of the Ni-CeO2 coatings。 Besides a variety of loading force was applied for hardness measurements, showing similar indentations and no obviously spalling behavior or micro cracks。 Attentively, a great difference in their indentations was the size and depth, as well as either convergence or pergency on the state of indentations edges。 A smller size and the convergence of hardness indentation recorded for the Ni-CeO2 coatings was indicative of higher hardness and  Young”s modulus, which was largely attributed to an increasing resistance of plastic deformation and strengthening dispersion by adding CeO2 nanoparticle or its precipiated Ce-rich phase。 The existence of the Ce-rich phase or its Ce solute atoms along defective boundaries or thermal micro cracks was avaiable for making the so-called Orowan by-passing mechanism for dislocations pile-up and and hindering the soliding dislocation,  void defects or cracking boundaries。

Keywords: titanium alloy; Ni-CeO2 nanocomposite coating; microstructure; mechanical properties

目 录

第一章 绪 论 1

1。1 纳米复合镀层 1

1。1。1 纳米复合镀层的研究进展 1

1。1。2 影响纳米复合镀层质量的因素 3

1。1。3 稀土纳米颗粒作用机理 4

1。2 超声辅助双脉冲电沉积技术简介 5

1。3 辅助超声震荡在电沉积过程中的应用 6

1。3。1 超声波对电沉积的作用机理 6

1。3。2 超声波对镀层表面形貌的影响 7

1。4 本文选题意义及主要研究内容 9

第二章 实验部分 11

2。1 实验药品与仪器 11

2。1。1  实验药品 11

2。1。2  实验仪器 11

2。2 钛基表面预处理 12

2。3 Ni-CeO2 纳米复合镀层的制备 13

2。4 测试与结构表征 16

2。4。1 XRD 射线衍射 16

2。4。2 FE-SEM 扫描电子显微镜测试 16

2。4。3 HV 显微硬度 17

2。4。4 纳米压痕技术 17

2。4。5 镀层附着力（划痕测试） 17

2。4。6 摩擦磨损性能 17

第三章 结果与讨论 18

3。1  添加 CeO2 对电沉积纳米晶 Ni 镀层组织形貌的影响 18

3。1。1  镀层表面形貌 FE-SEM 观察 18

3。1。2 织构生长 XRD 分析 22

3。2  力学性能 23

3。2。1 纳米压痕分析 24

3。2。2 硬度和韧性测试