航空学报 > 2024, Vol. 45 Issue (8): 429129-429129   doi: 10.7527/S1000-6893.2023.29129

激光熔覆修复GH4169合金各向异性拉伸性能

樊哲铭1, 杨未柱1,2(), 曾延1, 赵哲南1, 李磊1   

  1. 1.西北工业大学 力学与土木建筑学院,西安 710072
    2.西北工业大学深圳研究院,深圳 518063
  • 收稿日期:2023-06-05 修回日期:2023-07-07 接受日期:2023-08-22 出版日期:2024-04-25 发布日期:2023-09-01
  • 通讯作者: 杨未柱 E-mail:wzhyang@nwpu.edu.cn
  • 基金资助:
    广东省基础与应用基础研究基金(2023A1515012360);航空科学基金(2020Z039053002);国家科技重大专项(J2019-IV-)

Anisotropic tensile properties of GH4169 alloy repaired by laser direct energy deposition

Zheming FAN1, Weizhu YANG1,2(), Yan ZENG1, Zhenan ZHAO1, Lei LI1   

  1. 1.School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi’an  710072,China
    2.Research and Development Institute of Northwestern Polytechnical University in Shenzhen,Shenzhen  518063,China
  • Received:2023-06-05 Revised:2023-07-07 Accepted:2023-08-22 Online:2024-04-25 Published:2023-09-01
  • Contact: Weizhu YANG E-mail:wzhyang@nwpu.edu.cn
  • Supported by:
    Guangdong Basic and Applied Basic Research Foundation(2023A1515012360);Aeronautical Science Foundation of China(2020Z039053002);National Science and Technology Major Project(J2019-IV-0019-0087)

摘要:

激光熔覆修复GH4169合金的拉伸性能具备各向异性,拉伸性能与受载方向和修复界面之间的夹角(界面角度)显著相关,研究修复后合金的拉伸各向异性可为GH4169合金构件的高性能修复奠定基础。基于数字图像相关(DIC)技术开展了不同界面角度下的修复后合金拉伸试验,结合光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)等手段进行了界面区域微观组织及断口形貌观测分析,对激光熔覆修复GH4169合金各向异性拉伸力学性能开展了研究。结果表明修复后合金的拉伸性能与拉伸载荷方向、枝晶生长方向的夹角呈负相关;拉伸试样的断裂主要是由Laves/γ相界面在拉伸载荷下分离引发裂纹成核和扩展造成的。当枝晶取向与拉伸载荷的夹角较小时枝晶间较大尺寸的不规则Laves相破碎成小颗粒并随基体γ相一同移动,断裂后韧窝较深,抗拉强度和屈服强度较高;当夹角较大时枝晶间Laves/γ相界面剥离导致裂纹形核,而后快速扩展,断口呈大量阶梯状的枝晶沿晶断裂形貌,拉伸性能较差。研究阐明了不同界面角度对修复后合金拉伸性能的影响机理,可为激光熔覆修复GH4169高温合金构件拉伸性能的综合评估提供基础。

关键词: 激光熔覆, GH4169高温合金, 各向异性拉伸性能, 微观组织, 断裂机理

Abstract:

The tensile properties of GH4169 superalloy repaired by direct energy deposition are anisotropic, and there is a significant correlation between the tensile properties and the angle between the stress direction and the repair interface (interface angle). Studying the tensile anisotropy of the repaired alloy can lay the foundation for high-performance repair of GH4169 superalloy components. Based on Digital Image Correlation (DIC) technology, this study conducts tensile tests and mechanical behavior analysis of the repaired alloy at different interface angles, and combines Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and other methods to observe the microstructure and fracture morphology of the interface area. The anisotropic tensile mechanical properties of GH4169 alloy repaired by direct energy deposition were studied. The results indicate that the tensile properties of the repaired alloy exhibit a negative correlation with the angle between the tensile direction and dendrite growth direction; the fracture of tensile specimens is mainly caused by the separation of Laves/γ phase interface under tensile load, leading to crack nucleation and propagation. When the angle between dendrite orientation and tensile load is small, the larger irregular Laves phase between the dendrites breaks into small particles and moves along with the matrix γ phase, after fracture the dimples are deeper and the tensile strength and yield strength are higher; when the included angle is large, the delamination of Laves/γ phase interface between dendrites leads to crack nucleation, which then rapidly expands, and the fracture surface presents a large number of stepped dendritic intergranular fracture morphology, resulting in poor tensile performance. This study elucidates the mechanism of the influence of different stretching directions on the tensile properties of the repaired alloy, providing a basis for the comprehensive evaluation of the tensile properties of GH4169 superalloy components repaired by direct energy deposition.

Key words: laser cladding, GH4169 superalloy, anisotropic tensile properties, microstructure, fracture mechanism

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