γ/α2相界面对TiAl合金超音速微粒轰击影响的分子动力学模拟  

Effect ofγ/α2 Phase Interface on Supersonic Fine Particle Bombardment of TiAl Alloy by Molecular Dynamics Simulation

作　　者：曹卉[1,2] 王靖淇 周宝成[1] 俞兆亮 杨文乐 李海燕[1,2] 刘俭辉[1,2] 冯瑞成 Cao Hui;Wang Jingqi;Zhou Baocheng;Yu Zhaoliang;Yang Wenle;Li Haiyan;Liu Jianhui;Feng Ruicheng(School of Mechanical and Electrical Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Digital Manufacturing Technology and Application,Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学机电工程学院,甘肃兰州730050 [2]兰州理工大学数字制造技术与应用教育部重点实验室,甘肃兰州730050

出　　处：《稀有金属材料与工程》2024年第2期396-408,共13页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(52065036);Key Program of Natural Science Foundation of Gansu(23JRRA760);Natural Science Foundation of Gansu(22JR5RA298);Hongliu First-Class Disciplines Development Program of Lanzhou University of Technology。

摘　　要：为探究γ/α_(2)相界面对TiAl合金在轰击过程中的变形机制和轰击后力学性能的影响,通过分子动力学来模拟超音速微粒轰击双相TiAl合金的过程。结果表明:γ/α_(2)不同厚度比模型的冲击变形机制不同,变形主要集中在γ相和界面处。随着γ相厚度的减小,与相界面接触的位错首先被界面处的失配位错网络吸收,然后在相界面处成核,最终穿过相界面进入α_(2)相。冲击过程中产生的位错以Shockley位错为主,试样中形成了不完全层错四面体。冲击之后分别使用单轴拉伸模拟和纳米压痕模拟,测定了试样的强度和表面硬度。拉伸过程中相变、孪晶和层错是不同厚度比试样的主要变形机制。与其他试样相比,厚度比为1:3的双相TiAl合金在冲击后具有最高的屈服强度、硬度和弹性模量。In order to investigate the effect ofγ/α_(2) phase interface on the deformation mechanism and mechanical properties of TiAl alloy during bombardment process,the supersonic fine particle bombardment of dual-phase TiAl alloy was simulated by molecular dynamics.Results show that the impact deformation mechanisms ofγ/α_(2) models with different thickness ratios are different,and the deformation is mainly concentrated at theγphase and interface.With decreasing theγphase thickness,the dislocations in contact with the phase interface are firstly absorbed by the mismatched dislocation network,then they are nucleated at the phase interface,and eventually the dislocations pass through the phase interface,entering theα_(2) phase.Shockley dislocation is the main dislocation type in the impact process,and incomplete stacking fault tetrahedron forms in the specimen.After impact,uniaxial tensile simulation and nano-indentation simulation were conducted to measure the strength and surface hardness of the specimens.The main deformation mechanisms of specimens with different thickness ratios are the phase transformation,twins,and stacking faults during tensile process.Compared with other specimens,TiAl alloy with thickness ratio of 1:3 has the highest yield strength,the highest hardness,and the highest elastic modulus after impact.

关 键 词：分子动力学 相界面 TiAl/Ti3Al 力学性能 塑性变形 

分 类 号：TG146.23[一般工业技术—材料科学与工程]