| 摘要: |
| C 元素掺杂 TiAlN 涂层的增硬机理尚不明确，为了揭示 C 元素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 31.60 GPa；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，sp2 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。 |
| 关键词: TiAlCN 涂层 C 含量 硬度 第一性原理 |
| DOI：10.11933/j.issn.1007?9289.20220213002 |
| 分类号:TG147 |
| 基金项目:上海市自然科学基金资助项目(20ZR1455700) |
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| Hardness Evolution Mechanism of C-Doped TiAlN Coating |
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ZHOU Qiong1,2, TONG Xu1, ZHANG Ergeng1, HUANG Biao1, CHEN Qiang1, CHENG Xianhua2
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1.Shanghai Engineering Research Center of Physical Vapor Deposition (PVD) Superhard Coating and Equipment,Shanghai Institute of Technology, Shanghai 201418 , China;2.School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 , China
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| Abstract: |
| 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 sp2 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. |
| Key words: TiAlCN coating C content hardness first principles theory |
