| 引用本文格式: Zhou Shao-Lan,Cong Da-Long,Yang Jiu-Zhou,Li Li,Huang An-Wei,Ran Xu-Dong,Chen Han-Bin,Li Zhong-Sheng. A first-principles study of the stability and mechanical properties of Mo1-xWxC carbides [J]. J. At. Mol. Phys., 2024, 41(3): 036001 (in Chinese) [周少兰,丛大龙,杨九州,李立,黄安畏,冉旭东,陈汉宾,李忠盛. Mo1-xWxC碳化物稳定性及力学性质的第一性原理计算 [J]. 原子与分子物理学报, 2024, 41(3): 036001] |
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| Mo1-xWxC碳化物稳定性及力学性质的第一性原理计算 |
| A first-principles study of the stability and mechanical properties of Mo1-xWxC carbides |
| 摘要点击 123 全文点击 12 投稿时间：2022-11-07 修订日期：2022-11-22 |
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| DOI编号
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| 中文关键词
第一性原理 虚拟晶体近似 Mo1-xWxC 力学性质 |
| 英文关键词
first Principle, Virtual crystal approximation, Mo1-xWxC, Mechanical properties |
| 基金项目
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| 中文摘要
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| 金属碳化物作为基体的增强相，对钢铁的力学性能起到至关重要的作用。 采用基于密度泛函理论的第一性原理方法，通过虚拟晶体近似构建Mo1-xWxC（0≤X≤1）碳化物模型，计算Mo1-xWxC的晶格常数、形成能、结合能、弹性常数、弹性模量、泊松比u、维氏硬度、电子态密度等性质参数，分析W元素对MoC碳化物稳定性及力学性能的影响。 本次计算值与其他理论计算值及试验值吻合度较高；随着W含量的增加，晶格常数增加，Mo1-xWxC的形成能、结合能皆为负值，结合能、形成能的绝对值均随着W含量的增加而增加。不同掺杂含量下的Mo1-xWxC均满足Born判据，在力学上是稳定的，随着W含量的增加，Mo1-xWxC的弹性常数、体模量、杨氏模量、剪切模量呈线性增加，B/G、泊松比降低。Mo1-xWxC在费米能级处的态密度值均不为0，态密度值随着W含量的增加而降低。 Mo1-xWxC能自发形成且能稳定存在，随着W含量的增加，Mo1-xWxC碳化物的稳定性、弹性模量、硬度及耐磨性均增加，Mo1-xWxC呈脆性，脆性大小随着w含量的增加而增加。 |
| 英文摘要
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| Metal carbides, as the reinforcing phase of the matrix, play a crucial role in the mechanical properties of steel. A first-principles approach based on density generalized theory is used to construct a Mo1-xWxC (0 ≤ X ≤ 1) carbide model by virtual crystal approximation to calculate the property parameters, such as lattice constants, formation energy, binding energy, elastic constant, elastic modulus, Poisson's ratio u, Vickers hardness, and density of electronic states of Mo1-xWxC. The effects of W elements on the stability and mechanical properties of MoC carbides were analyzed. The calculated values are in good agreement with other theoretical and experimental values; the lattice constants increase with the increase of W content, the formation energy and binding energy of Mo1-xWxC are negative, and the absolute values of binding energy and formation energy increase with the increase of W content. The Mo1-xWxC with different doping contents satisfy the Born criterion and are mechanically stable. the elastic constants, bulk modulus, Young's modulus and shear modulus of Mo1-xWxC increase linearly with the increase of W content, and the B/G and Poisson's ratio decrease. The density of states values of Mo1-xWxC at the Fermi energy level are not zero, and the density of states values decrease with the increase of W content. Mo1-xWxC can form spontaneously and exists stably. The stability, elastic modulus, hardness and wear resistance of Mo1-xWxC carbides increase with the increase of W content, Mo1-xWxC is brittle, and the brittleness increases with the increase of w content. |
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