不同温度下纯Ni/NiTi合金的摩擦特性研究  

Study on Friction Characteristics of Pure Ni/NiTi Alloy at Different Temperatures

作　　者：李锐[1] 曾令碧 刘腾 王晓杰[1] 杨平安 LI Rui;ZENG Lingbi;LIU Teng;WANG Xiaojie;YANG Ping’an(College of Automation,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;College of Advanced Manufacturing Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Chongqing Konka Optoelectronics Research Institute Co.,Ltd.,Chongqing 402760,China)

机构地区：[1]重庆邮电大学自动化学院,重庆400065 [2]重庆邮电大学先进制造工程学院,重庆400065 [3]重庆康佳光电研究院有限公司,重庆402760

出　　处：《材料导报》2020年第S01期297-303,共7页Materials Reports

基　　金：重庆市技术创新与应用发展专项重点项目(cstc2019jscx-fxydX0085);重庆市教育委员会科学技术研究项目(KJZD-K201900602)。

摘　　要：NiTi合金具有形状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。为从微观角度揭示其摩擦特性,利用分子动力学研究了不同温度下纯Ni和NiTi合金的压/划痕过程,并进一步通过对比分析不同温度下纯Ni和NiTi合金在压/划痕过程中原子结构、表面形貌、摩擦力和摩擦系数的变化,研究了温度对NiTi合金摩擦系数的影响。结果表明,温度对NiTi合金摩擦性能的影响显著,在300~500 K范围内,温度越低,摩擦力与摩擦系数越小,这是由于在刻划过程中NiTi合金发生马氏体相变,NiTi合金表面向下凹陷,减少了NiTi表面与压头的接触,降低了对压头的阻碍,使摩擦力与摩擦系数大幅降低;当温度升高时,马氏体相变减少,NiTi合金的表面凹陷减少,使压头与NiTi合金的接触面积增大,阻碍增大,从而使得摩擦力和摩擦系数变大。而没有相变机制的金属Ni在刻划过程中,主要产生塑性形变,温度对其摩擦性能无显著影响。可见,温度对NiTi形状记忆合金的摩擦性能具备一定调控能力,可以通过控制温度达到减少磨损的目的,这可为延长NiTi合金元件的使用寿命提供理论基础和指导。NiTi alloy has shape memory effect and superelasticity,which makes it different from other general materials.In order to reveal its friction characteristics from a micro perspective,the dynamics of pure Ni and NiTi alloys at different temperatures were studied using molecular dynamics and Scratching process.By comparing and analyzing the changes in the atomic structure,surface morphology,friction force and friction coefficient of pure Ni and NiTi alloys during the pressing and scratching process at different temperatures,the effect of temperature on the friction coefficient of NiTi alloys was studied.The results show that the temperature has a significant effect on the friction properties of NiTi alloys.In the temperature range of 300—500 K,the lower the temperature,the smaller the friction and coefficient of friction.This is due to the martensitic phase change of the NiTi alloy during the scoring process,the surface of the NiTi alloy is recessed downward,reducing the contact between the NiTi surface and the indenter,reducing the obstacle to the indenter,and greatly reducing the friction.When the temperature increases,the martensitic phase transformation decreases and the surface of the NiTi alloy is depressed.Decreasing the degree will increase the contact area between the indenter and the NiTi alloy,and increase the obstacle,which will increase the friction force and friction coefficient.However,during the scoring process of the metal Ni without a phase change mechanism,the plastic deformation and temperature are mainly generated.It has no significant effect on its friction performance,and its friction and coefficient of friction do not fluctuate significantly at different temperatures.Therefore,tempe-rature has a certain ability to regulate the friction properties of NiTi shape memory alloys,and the purpose of reducing wear can be achieved by controlling the temperature,which provides a theoretical basis and guiding for improving the service life of NiTi alloy components.

关 键 词：NITI形状记忆合金 分子动力学 摩擦 温度 相变 

分 类 号：TB31[一般工业技术—材料科学与工程]