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1、太原理工大学 硕士学位论文 非平衡磁控溅射Ti-Ni合金薄膜的制备及其力学性能研究 姓名：贺耀华 申请学位级别：硕士 专业： 指导教师：贺志勇;鲍明东 太原理工大学硕士研究生学位论文 I 非平衡磁控溅射 Ti-Ni 合金薄膜的制备及其力学性能研究 摘 要 自 20 世纪 60 年代以来，Ti-Ni 合金由于良好的形状记忆效应得到越来 越多的应用。然而，在过去的 20 多年里，该合金的耐磨性开始得到重视。 采用Ti-Ni薄膜作为材料的耐磨改性层在最近成为新的研究方向。 对于Ti-Ni 薄膜材料，组织结构和性能有较强的成分敏感性，因此很有必要深入研究 Ti-Ni 合金薄膜的制备工艺，以精确控制薄膜
2、成分。通过对不同成分薄膜微 观结构、相变温度、表面形貌及力学性能的分析研究，可以探索 Ti-Ni 薄膜 摩擦学行为的机理问题，分析其影响因素，并为充分发挥其特性提供依据。 本文采用闭合场非平衡磁控溅射离子镀技术，制备出成分为 45.4at.%Ti、46.8at.%Ti、49.7at.%Ti、51.3at.%Ti 和 53.3at.%Ti 的 Ti-Ni 合金 薄膜。并通过 EDXA、FSEM、AFM 和 XRD 等手段，检测薄膜的成分、表 面截面形貌和相结构。同时，采用 DSC 和纳米压痕仪等仪器，测试薄膜的 相变温度、显微硬度和弹性模量。另外，在膜层成分为 49.7at.%Ti 的情况 下，
3、设计由三种成分梯度分布的过渡层薄膜，通过附着力自动划痕仪和球 盘磨损试验机等设备检测薄膜的结合强度、摩擦系数及磨损率。在试验结 果基础上，探讨了 Ti-Ni 薄膜的摩擦学行为机理。 通过研究和分析，得到的主要结论有： 1. 制备近等原子比 Ti-Ni 合金薄膜的最佳工艺参数：氩气流量为 30sccm，偏压为 60V，TiNi 合金靶电流为 6A，Ti 靶电流为 3A，晶化温度 太原理工大学硕士研究生学位论文 II 为 600。 2. 随着 Ti 原子百分含量的增加， Ti-Ni 合金薄膜的 Ms 出现先升高后趋 于稳定的态势，在近等原子比时达到最大；其表面粗糙度先减小后增大， 在近等原子比时达
4、到最小。 3. 在相同的载荷下， Ti-Ni 合金薄膜的显微硬度和弹性模量先增大后减 小。不同载荷下，二者的变化并不明显；随着 Ti 原子百分比的提高，薄膜 的伪弹性回复率 先增大后减小。 4. Ti-Ni 薄膜的摩擦系数比钛合金小；薄膜的磨损率比基体低一个数量 级，且薄膜的磨损轨迹比基体的窄一些。 总之，Ti-Ni 薄膜相对于基体的摩擦磨损性能的提高主要与其超弹性有 关，薄膜良好的应变硬化效应、热硬性和抗疲劳等特性也可能有助于提高 薄膜的耐磨性。另外，薄膜的成分、相结构等因素都会影响到薄膜的超弹 性。 关键词：Ti-Ni 合金薄膜，磁控溅射离子镀，成分，结构，力学性能 太原理工大学硕士研究生
5、学位论文 III STUDY ON PREPARATION OF Ti-Ni ALLOY FILMS BY UNBALANCED MAGNETRON SPUTTERING AND ITS MECHANICAL PROPERTIES ABSTRACT Since the 1960s, Ti-Ni alloys have been developed as shape memory alloy due to their excellent shape memory effect. However, during the past two decades, TiNi alloys wear resi
6、stance has attracted more and more attention. In recent years, using TiNi thin film to improve wear resistance of materials has become an updated research area. For Ti-Ni thin film, its structure and propertie are sensitive to composition, therefore, it is necessary to study the preparation conditio
7、n to precisely control the composition of the film. The mechanisms responsible for the tribological performance of Ti-Ni film could be revealed through investigation to microstructure, phase transition temperature, surface morphology and mechanical properties of films with different composition. The
8、se fundamental studies are beneficial to promote the application of TiNi films as wear resistant material. In this paper, the Ti-Ni alloy films with 45.4at.%, 46.8at.%, 49.7at, 51.3at.% and 53.3at.% Ti content were prepared using closed field unbalanced magnetron sputtering process. The composition,
9、 surface morphology and phase structure of the films were tested by EDXA, FSEM, AFM and XRD, respectively. Meanwhile, the phase transition temperature, micro-hardness and elastic modulus were analyzed by DSC, nano-indenter and the other instruments. 太原理工大学硕士研究生学位论文 IV In addition, three types of tra
10、nsition layer were designed for film of 49.7at.% Ti content. Bonding strength, friction coefficient and wear rate were tested by automatic scratch tester and ball-disc wear tester. Finally, the mechanism of tribological behavior for Ti-Ni thin films was discussed. Through the above research and anal
11、ysis, the main conclusions are obtained as follows: 1. The optimum process parameters for the preparation of Ti-Ni alloy thin film with nearly equal atomic ratio is: argon flows 30sccm, bias 60V, Ti-Ni alloy target current 6A, Ti target current 3A. 2. With the increase of Ti content, Ms temperature
12、of Ti-Ni alloy films increases firstly and then tends to keep stable, the maximum occurs at nearly equal atomic ratio; the surface roughness of Ti-Ni alloy thin films decreases at first and then increases, the minimum occurs also at the nearly equal atomic ratio. 3. For the same load, the micro-hard
13、ness and elastic modulus firstly increase and then decrease with the increase of Ti content; Under different loads, they have no obvious change. The pseudo-elastic recovery rate of the films is independent of applied load, it increases firstly and then decreases as the Ti content increases. 4. Frict
14、ion coefficient of the Ti-Ni alloy film is smaller than that of TC4 substrate material. Wear rate of the film is an order of magnitude lower than the substrate, and wear track is also narrower. 太原理工大学硕士研究生学位论文 V In summary, the improvement in tribological properties of Ti-Ni thin films is mainly rel
15、ated to its super-elastic transformation ， and the superb strain-hardening , hot hardness and anti-fatigue properties also possibly contribute to the wear resistance. Besides, composition, phase structure and the other factors also affect the super-elastic of TiNi thin films. KEY WORDS：Ti-Ni alloy f
16、ilm, magnetron sputter ion plating, composition, structure, mechanical properties 太原理工大学硕士研究生学位论文 1 第一章 绪论 1.1 引言 形状记忆材料是二十世纪七十年代才发展起来的一种新型的功能材料。 这种材料包 括高分子和晶体两大类， 高分子材料借玻璃态转变或其它物理条件的激发呈现形状记忆 效应（Shape Memory Effect，简称 SME）1，而晶体材料是通过马氏体相变实现的。 形状记忆材料通常也被称为机敏材料（Smart Material） ，具有精确的形状记忆回复 功能。可以将电能、热能直接转化成机械能，输出应变、应力大，并且功率可调节，具 备其它材料所不能代替的功能。它是智能材料的基础形式，是智能材料研究所达到的最 新阶段，也是进一步研究智能材料的基点。形状记忆材料在航天器、桥涵、抗震建筑、 高速轨道、人体损坏修复，特别是在微机电系统等领域能够发挥独特的作用，有着广阔 的应用前景2。 在晶体材料中，形状记忆效应的表现为：当一定形
