C掺杂TiAlN涂层的硬度演变机理  

Hardness Evolution Mechanism of C-Doped TiAlN Coating

作　　者：周琼 仝旭[1] 张而耕 黄彪 陈强 程先华 ZHOU Qiong;TONG Xu;ZHANG Ergeng;HUANG Biao;CHEN Qiang;CHENG Xianhua(Shanghai Engineering Research Center of Physical Vapor Deposition(PVD)Superhard Coating and Equipment,Shanghai Institute of Technology,Shanghai 201418,China;School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海应用技术大学上海物理气相沉积(PVD)超硬涂层及装备工程技术研究中心,上海201418 [2]上海交通大学机械与动力工程学院,上海200240

出　　处：《中国表面工程》2022年第6期140-149,共10页China Surface Engineering

基　　金：上海市自然科学基金资助项目(20ZR1455700)。

摘　　要：C元素掺杂TiAlN涂层的增硬机理尚不明确,为了揭示C元索对涂层硬度的作用规律,采用阴极电弧离子镀膜技术在316不锈钢表面制备C原子比率分别为0%、3.87%、9.24%、14.76%、20.57%、25.90%的TiAlCN涂层,通过试验研究和密度泛函理论系统地从原子量级角度阐述C掺杂对涂层硬度的作用规律及机理。研究结果表明:C原子会置换TiAlN晶胞中的部分N原子形成TiAlCN固溶体相:随着C含量的增加,涂层硬度呈现先上升后下降的趋势,在C含量为14.76%时,涂层中Ti-N键转化成为Ti-C键的数量达到饱和,硬度达到最高值31.60GPa;当C原子含量高于14.76%时,涂层中出现类石墨结构,且随着C含量的增加,sp^(2)层状结构增多,在抵抗外界压力时石墨层发生侧滑,涂层硬度降低;第一-性原理数值模拟结果显示,随着C含量从0%增加到15.625%,涂层硬度逐渐上升是由于共价性较强的Ti-C键逐渐增加。阐明C元素掺杂对涂层硬度的作用变化规律,有利于指导超硬涂层的工艺设计和生产。The hardening mechanism of C element doped TiAlN coating is not clear.In order to reveal the effect of element C on the hardness of the coating,TiAlCN coating with C atom ratios of 0%,3.87%,9.24%,14.76%,20.57%and 25.90%are prepared on the surface of 316 stainless steel by cathodic arc ion plating technology.The effect of C doping on the hardness of coatings and its mechanism are expounded from the point of view of atomic scale through experimental research and density functional theory.The research results show that C atoms replace part of N atoms in TiAlN cell to form TiAlCN solid solution phase.With the increasing of C content,the hardness of the coating increases firstly and then decreases.When the C content is 14.76%,the number of Ti-N bonds converted into Ti-C bonds in the coating reaches saturation,and the hardness reaches the highest value of 31.60 GPa.When the content of C atom is higher than 14.76%,the graphite-like structure appears in the coating.With the increasing of C atom content,the sp^(2) layer structure increases,the graphite layer slips and the hardness of the coating decreases.The results of first-principles numerical simulation show that with the increasing of C content from 0%to 15.625%,the hardness of the coating increases gradually because of the increasing of Ti-C bond with strong covalence.Therefore,it is beneficial to guide the deposition process design and production of superhard coating to clarify the relationship between C element doping and the coating hardness.

关 键 词：TiAlCN涂层 C含量 硬度 第一性原理 

分 类 号：TG147[一般工业技术—材料科学与工程]