单晶金刚石切削模具钢磨损机理的分子动力学仿真  

Wear Mechanism of Single Crystal Diamond Tool Against Mold Steel by Molecular Dynamics Simulation

作　　者：金洙吉[1] 谢飞[1] 郭晓光[1] 史双佶[1] Jin Zhuji Xie Fei Guo Xiaoguang Shi Shuangji(Key Laboratory for Precision and Non-Traditional Machining of Ministry of Education, Dalian University of Technology, Dalian 116024, China)

机构地区：[1]大连理工大学精密与特种加工教育部重点实验室,大连116024

出　　处：《纳米技术与精密工程》2016年第6期410-415,共6页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金创新研究群体资助项目(51321004)

摘　　要：为了研究金刚石刀具切削模具钢过程中刀具的磨损机理,建立了金刚石切削模具钢的仿真模型.通过观察切削过程中金刚石原子空间角度变化情况,分析刀具的切削温度、径向分布函数(RDF)和配位数,进一步阐明了金刚石纳米级切削铁的过程中刀具的微观磨损机理,并利用金刚石刀具的磨损实验验证仿真结果.结果表明:铁原子含有未配对d电子,并且铁在(111)面上与金刚石(111)面上的原子符合垂直对准原则,这两个原因导致铁易与金刚石原子形成化学键,与金刚石(111)面上符合垂直对准原则的铁原子同时驱动金刚石原子运动,促使金刚石结构转化为石墨结构.进行了金刚石磨损实验,结果表明:铁与金刚石中的碳产生碳化铁,刀具由金刚石结构转变为石墨结构,铁对金刚石石墨化具有催化作用.To research the wear mechanism of diamond tool, a simulation model of diamond tool turning mold steel was established. The wear mechanism of diamond tool was further clarified from the point of view of atomic position variation, temperature fluctuations, radial distribution function （RDF） and coor- dination number were involved. The simulation result has been verified by diamond tool friction experi- ments. Results show that iron atoms have unpaired d electrons, and that these iron atoms may connect with diamond carbon atoms through chemical bonds which are the driving force to the diamond removal and thus making diamond convert into graphite. Moreover, the atomic arrangement on （111 ） surface of both iron and diamond agreed with the vertical aligned principle so that the iron atoms could have a con- centrated effect on the diamond. The experiment of machining iron with a diamond tool shows that iron and carbon atoms produced iron carbide, that the tool transformed diamond structure into a graphite struc- ture, and that iron catalyzed diamond graphitization.

关 键 词：金刚石石墨化 磨损机理 模具钢 分子动力学仿真 

分 类 号：TG501.1[金属学及工艺—金属切削加工及机床] TH117.1[机械工程—机械设计及理论]