NiTi形状记忆合金摩擦过程的影响因素研究

发布时间：2017-06-10 12:13

  本文关键词：NiTi形状记忆合金摩擦过程的影响因素研究，，由笔耕文化传播整理发布。

【摘要】：镍钛合金最重要的两个特征为记忆效应和超弹性。因其具有这样的特性,使得该合金广泛应用于:宇宙航空、机械、电子、能源、民生、医学。因为镍钛合金具有记忆效应及超弹性特性,使得它与其他一般材料的摩擦特性有很大不同。当温度升高至某一特定温度下(这一温度值与合金中的镍含量有关)的时候马氏体相将发生向奥氏体相转变的相变过程;当温度下降至某一特定温度时,奥氏体相将发生向马氏体相的逆相变过程。另外,应力也会导致合金发生相变:镍铁合金在奥氏体相时,如果有足够大的载荷作用,将会发生奥氏体相向马氏体相转变的相变过程,在卸载后,可自动恢复原来的相(奥氏体)。如果材料发生相变,合金的机械性能将发生完全改变,导致摩擦磨损性能改变,因此会显著影响机器设备的寿命及运行性能。因此通过对镍钛合金的摩擦磨损性能过程影响因素(温度、载荷)的研究,可以为减少摩擦、磨损提供有意义的指导。为了研究宏观摩擦磨损性能,论文根据王亚珍[1]建立的Hertz单点接触模型,利用机械-分子作用理论对镍钛合金的温度和应力影响下的摩擦学性能进行了计算。该模型包括一个钢球在用镍钛合金制造的平面上滑动。对于普通的材料,Hertz单点接触模型在接触区上给出的应力分布是一个半椭球体。但是对于镍钛合金,应力图不再是一个固定的半椭圆体,而与温度和载荷有关。然后,根据相变温度图和应力-应变图来确定载荷、温度和摩擦接触区性质之间的关系。根据理论分析的结果,本文还进行与Herzt点接触模型一样工况下的验证实验,实验是在MS-T3000摩擦磨实验机上进行的,然后利用Taylorsurf-1000对实验结果进行了测量与分析。在此基础上,本文还对微观摩擦磨损特征进行了研究,本文根据CO振子模型[2]建立的相应公式计算静摩擦力和滑动摩擦力。并利用原子力显微镜(AFM)对计算结果进行了验证。本文对载荷、温度、速度等因素对于镍钛合金因相变引起的宏观和微观摩擦磨损过程的影响规律进行了较深入的研究,以期帮助我们找到减摩耐磨的实用方法和手段。
【关键词】：NiTi形状记忆合金 摩擦磨损 Hertz单点接触模型 CO振子模型 理论分析 实验
【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG139.6
【目录】：

• 摘要5-6
• Abstract6-12
• Table of common symbols12-14
• Chapter 1 Introduction14-37
• 1.1 History of NiTi alloy14-16
• 1.2 Characteristics of Ni Ti alloy16-20
• 1.2.1 Shape memory effect17-18
• 1.2.2 Super-elastic18-20
• 1.3 Application and research status of NiTi alloy20-22
• 1.3.1 Application areas of NiTi alloy20-21
• 1.3.2 Current status and research trends21-22
• 1.4 Status of research problems friction and wear of NiTi shape memory alloy22-32
• 1.4.1 Friction of Ni Ti shape memory alloy22-27
• 1.4.2 Wear of Ni Ti shape memory alloy27-32
• 1.5 Effects of temperature on friction and wear32-35
• 1.6 Meanings and contents of the present thesis35-37
• 1.6.1 Meanings35-36
• 1.6.2 Contents of the present thesis36-37
• Chapter 2 Model of NiTi alloy in Hertz point contact37-55
• 2.1 Introduction37
• 2.2 Molecular mechanical friction theory37-48
• 2.2.1 Nature of molecular mechanical friction37-40
• 2.2.2 Method of defining molecular friction component40-41
• 2.2.3 Mechanical friction component definition method41-45
• 2.2.4 General friction coefficient calculation method45-47
• 2.2.5 Factors affecting friction coefficient47-48
• 2.3 Modeling Hertz point contact for NiTi alloy48-53
• 2.4 Chapter conclusions53-55
• Chapter 3 Experimental research on macro tribological features of NiTi alloy55-75
• 3.1 Introduction55-56
• 3.2 Rules of experimental tribology56-63
• 3.2.1 Nature of external friction56-60
• 3.2.2 Dependence of friction coefficient on normal pressure60-62
• 3.2.3 The dependence of friction coefficient on sliding velocity f=f(v)62-63
• 3.2.4 Dependence of friction coefficient on other parameters63
• 3.3 Experimental equipment, sample and conditions63-65
• 3.3.1 Expermental equipment63-65
• 3.3.2 Sample65
• 3.3.3 Experimental conditions65
• 3.4 Influence of normal load65-70
• 3.5 Influence of sliding speed70-72
• 3.6 Influence of temperature72-73
• 3.7 Chapter conclusions73-75
• Chapter 4 Methods of measuring friction by AFM75-87
• 4.1 Introduction75-76
• 4.2 Structure, principle, operating mode and scan mode of AFM76-80
• 4.2.1 Structure of AFM76-77
• 4.2.2 AFM principle and operation mode77-79
• 4.2.3 AFM scanning mode79-80
• 4.3 Probe of AFM80-81
• 4.4 Methods of surface morphology measurement81
• 4.5 Methods of measuring friction81-84
• 4.6 Heating system of sample84-86
• 4.7 Chapter conclusions86-87
• Chapter 5 Interface friction oscillator model87-99
• 5.1 Introduction87-88
• 5.2 Oscillator friction model88-93
• 5.2.1 Independent oscillator model88-90
• 5.2.2 Composite oscillator model90-91
• 5.2.3 FK model91-92
• 5.2.4 FKT model92-93
• 5.2.5 Coupled oscillator (CO) model93
• 5.3 Definition of friction force basing on coupled oscillator model93-98
• 5.3.1 Coupled oscillator model93-96
• 5.3.2 Calculation of micro friction force while using AFM96-98
• 5.4 Chapter conclusions98-99
• Chapter 6 Experimental research on atomic scale friction of Ni Ti alloy99-122
• 6.1 Introduction99
• 6.2 Experimenting method and data handling method99-105
• 6.2.1 Experimenting steps99-102
• 6.2.2 Relationship between input voltage signal and load value102
• 6.2.3 Methods of measuring friction force and handling data102-105
• 6.3 Influence of normal load105-112
• 6.3.1 Static friction force105-107
• 6.3.2 Sliding friction force107-112
• 6.4 Influence of sliding speed112-116
• 6.5 Influence of temperature116-121
• 6.5.1 Influence of temperature on micro shape surface116-118
• 6.5.2 Influence of temperature on friction force118-121
• 6.6 Chapter conclusions121-122
• Chapter 7 Experimental research on wear features of NiTi alloy122-140
• 7.1 Introduction122
• 7.2 Nature of wear122-123
• 7.3 The factors impacting wear intensity123-125
• 7.4 Experimental research on wear features of NiTi alloy125-139
• 7.4.1 Summary on micro wear features of NiTi alloy125-130
• 7.4.2 Experiment and analysis on macro wear features of NiTi alloy130-139
• 7.5 Chapter conclusions139-140
• Chapter 8 Conclusions and future works140-146
• 8.1 Conclusions140-144
• 8.2 Future works144-146
• References146-158
• 攻读博士学位期间取得的研究成果158-159
• Acknowledgements159-160
• 附件160

【参考文献】

中国期刊全文数据库 前3条

1 姚骏恩;纳米测量仪器和纳米加工技术[J];中国工程科学;2003年01期

2 Ｍ．Ｂｉｅｎｉａｓ,Ｋ．Ｈａｓｃｈｅ,Ｒ．Ｓｅｅｍａｎｎ,Ｋ．Ｔｈｉｅｌｅ,赵克功,高思田,徐毅;计量型原子力显微镜[J];计量学报;1998年01期

3 张涛,王慧,胡元中;无磨损摩擦的原子理论[J];摩擦学学报;2001年05期

  本文关键词：NiTi形状记忆合金摩擦过程的影响因素研究，由笔耕文化传播整理发布。

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