W掺杂Ti(C_(0.5)N_(0.5))的电子结构及力学性能的理论分析  

Theoretical Analysis of Electronic Structure and Mechanical Properties of W-Doped Ti(C_(0.5)N_(0.5))

作　　者：熊萧 董定乾 熊健松 贺逢源 陈鑫辉 熊慧文[3] 张立[3] Xiong Xiao;Dong Dingqian;Xiong Jiansong;He Fengyuan;Chen Xinhui;Xiong Huiwen;Zhang Li(College of Mechanical Engineering,Sichuan University of Science and Technology,Zigong Sichuan 643000,China;Zigong Xili Numerical Control Tool Co.,LTD..Zigong Sichuan 643000,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha Hunan 410000,China)

机构地区：[1]四川轻化工大学机械工程学院,四川自贡643000 [2]自贡市希力数控工具有限公司,四川自贡643000 [3]中南大学粉末冶金国家重点实验室,湖南长沙410000

出　　处：《硬质合金》2024年第1期1-11,共11页Cemented Carbides

基　　金：国家自然科学基金(52374371,52074365);四川轻化工大学人才基金项目(2021RC18);四川省科技计划资助(2022YFG0289);过程装备与控制工程四川省高校重点实验室开放基金项目(GK202104,GK202106)。

摘　　要：采用密度泛函理论(DFT)的第一性原理方法对金属原子W掺杂Ti(C_(0.5)N_(0.5))的晶格常数、弹性常数和电子结构以及电荷布居进行计算和分析,结果表明:W原子可稳定存在于(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))中,但W原子的加入使得(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))体系稳定性下降,增强了原子间的键能,且晶格因替换原子W与Ti的直径大小不同产生畸变,并伴随着W含量的增加会加剧晶格畸变和晶格常数失衡;由弹性常数计算结果表明,适当添加W原子能改善(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))的抵抗外力变形的能力和硬度,同时可以降低晶体的脆性,且当x(W)=12%时,(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))抵抗变形能力和硬度达到最佳,理论硬度HV提高了6%;电子结构计算结果显示,W原子掺杂后费米能级处态密度增加,增强了(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))的导电性,且远高于Ti(C_(0.5)N_(0.5))的导电性;通过差分电荷密度图发现,W原子掺杂替换Ti会与C原子形成极性共价键,可以改善(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))的固有力学性能。The lattice constants,elastic constants,electronic structure,and charge distribution of Ti(C_(0.5)N_(0.5))doped with metal W atoms were calculated and analyzed by using the first-principles method of density functional theory(DET).The results show that W atoms can exist in(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))stably,but the addition of W atoms decreases the stability of the(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))system,enhances the bonding energy among atoms,and distorts the lattice as Ti atoms and W atoms have different diameters.With the increase in W content,lattice distortion and lattice constant imbalance will be aggravated.The results of elastic constant calculation show that the appropriate addition of W atoms can improve the deformation resistance and hardness of(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))and reduce the brittleness of the crystal.When x(W)=12%,the deformation resistance and hardness of(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))are the best.The theoretical hardness HV is increased by 6%.The calculation results of the electronic structure show that the state density increases at the Fermi level after doping W atoms,and the conductivity of(Ti_(1-x)W_(x))(C_(0.5)N_(0.5))is enhanced,which is much higher than that of Ti(C_(0.5)N_(0.5)).The charge difference density diagram shows that W atoms doping and replacing Ti atoms will form a polar covalent bond with C atoms,which can improve the inherent mechanical properties of(Ti_(1-x)W_(x))and(C_(0.5)N_(0.5)).

关 键 词：TICN 第一性原理 稳定性 力学性能 电子结构 

分 类 号：TG148[一般工业技术—材料科学与工程]