航空学报 > 2025, Vol. 46 Issue (21): 532318-532318   doi: 10.7527/S1000-6893.2025.32318

中国飞机强度研究所建所 60 周年专刊

应变速率对Ti-6Al-4V双相合金层裂强度的影响

杨千华1,2, 杨扬1(), 王彬文2, 郭玉佩2   

  1. 1.中南大学 材料科学与工程学院,长沙 410083
    2.中国飞机强度研究所 强度与结构完整性国家重点实验室,西安 710065
  • 收稿日期:2025-05-29 修回日期:2025-06-17 接受日期:2025-07-11 出版日期:2025-07-16 发布日期:2025-07-15
  • 通讯作者: 杨扬 E-mail:yangyang@csu.edu.cn
  • 基金资助:
    国家自然科学基金(51871243);湖南省自然科学基金(2019JJ40381);强度与结构完整性全国重点实验室开放基金(ASSIKFJJ202304001);湖北省爆破工程重点实验室联合开放基金(PBSKL2022C01);粤港澳中子散射科学技术联合实验室开放课题(HT-CSNS-DG-CD-0092/2021);工程材料与结构冲击振动四川省重点实验室开放基金(22kfgk06);湖北隆中实验室开放基金(2022KF-08)

Effect of strain rate on spall strength of Ti-6Al-4V dual-phase alloy

Qianhua YANG1,2, Yang YANG1(), Binwen WANG2, Yupei GUO2   

  1. 1.School of Materials Science and Engineering,Central South University,Changsha 410083,China
    2.National Key Laboratory of Strength and Structural Integrity,Aircraft Strength Research Institute of China,Xi’an 710065,China
  • Received:2025-05-29 Revised:2025-06-17 Accepted:2025-07-11 Online:2025-07-16 Published:2025-07-15
  • Contact: Yang YANG E-mail:yangyang@csu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(51871243);Hunan Provincial Natural Science Foundation(2019JJ40381);Open Fund of National Key Laboratory of Strength and Structural Integrity(ASSIKFJJ202304001);Joint Open Fund Project of Hubei Provincial Key Laboratory of Blasting Engineering(PBSKL2022C01);Open Project of Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology(HT-CSNS-DG-CD-0092/2021);Open Fund Project of Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province(22kfgk06);Open Fund Project of Hubei Longzhong Laboratory(2022KF-08)

摘要:

为探究应变速率对双相合金层裂强度的影响,采用分子动力学方法模拟了Ti-6Al-4V双相合金在不同冲击速度下的层裂过程,发现随着应变速率增大,其层裂强度先增大后减小。首次提出并验证了层裂机制由经典层裂变为微层裂时存在临界应变速率(ε˙c)。ε˙ε˙c时发生经典层裂,ε˙>ε˙c时发生微层裂。揭示了层裂机制由经典层裂变为微层裂时的内在机理与位错密度和熔化程度密切相关。发生经典层裂时,孔洞在两相向而行的稀疏波相遇产生的拉伸应力下形核,位错密度增加导致层裂强度增大。发生微层裂时,孔洞在拉伸应力和高温熔化的力热耦合影响下形核、长大和贯通,熔化程度增大导致层裂强度减小。

关键词: 分子动力学, 层裂强度, 经典层裂, 微层裂, Ti-6Al-4V双相合金

Abstract:

To investigate the effect of strain rate on spall strength of Ti-6Al-4V dual-phase alloy, the spall processes of Ti-6Al-4V dual-phase alloy under different impact velocities were simulated by molecular dynamics method. It was found that the spall strength increased first and then decreased with increasing strain rate. The critical strain rate (ε˙c) for the transformation of spall mechanism from classic spall to micro-spall was proposed and verified for the first time. The classic spall occurred when ε˙ε˙c, while the micro-spall occurred when ε˙>ε˙c. It was revealed that the internal mechanism for the transformation of spall mechanism from classic spall to micro-spall was closely related to dislocation density and melt ratio. The voids nucleated under the tensile stress produced by the meeting of two opposite rarefaction waves when the classic spall occurred. The increase of dislocation density led to the increase of spall strength. The voids nucleated under the stress-thermal synergistic effect of tensile stress and high temperature melt when the micro-spall occurred. The increase of melt ratio led to the decrease of spall strength.

Key words: molecular dynamics, spall strength, classic spall, micro-spall, Ti-6Al-4V dual-phase alloy

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