航空学报 > 2025, Vol. 46 Issue (17): 431717-431717   doi: 10.7527/S1000-6893.2025.31717

基于裂纹萌生与扩展的选区激光熔化Al-Mg-Sc-Zr合金疲劳寿命分析

邹君1(), 陈翥仪2, 夏晓宇1, 冯振宇3   

  1. 1.中国民航大学 安全科学与工程学院,天津 300300
    2.中国民航大学 中欧航空工程师学院,天津 300300
    3.中国民航大学 科技创新研究院,天津 300300
  • 收稿日期:2024-12-16 修回日期:2025-01-14 接受日期:2025-05-26 出版日期:2025-06-06 发布日期:2025-06-05
  • 通讯作者: 邹君 E-mail:jzou@cauc.edu.cn
  • 基金资助:
    航空科学基金(2024Z057067003);机械结构力学及控制国家重点实验室开放课题(MCMS-E-0522Y03);中央高校基本科研业务费专项资金(3122025084)

Fatigue life analysis of selective laser melting Al-Mg-Sc-Zr alloy based on crack initiation and propagation

Jun ZOU1(), Zhuyi CHEN2, Xiaoyu XIA1, Zhenyu FENG3   

  1. 1.College of Safety Science and Engineering,Civil Aviation University of China,Tianjin 300300,China
    2.Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China
    3.Science and Technology Innovation Institute,Civil Aviation University of China,Tianjin 300300,China
  • Received:2024-12-16 Revised:2025-01-14 Accepted:2025-05-26 Online:2025-06-06 Published:2025-06-05
  • Contact: Jun ZOU E-mail:jzou@cauc.edu.cn
  • Supported by:
    Aeronautical Science Foundation of China(2024Z057067003);Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(MCMS-E-0522Y03);Fundamental Research Funds for the Central Universities(3122025084)

摘要:

增材制造因其自由成形、快速制造的特点在航空领域具有重要应用价值。然而,增材制造材料的疲劳性能存在显著的分散性,如何准确评估其疲劳寿命已成为在航空领域应用面临的重要挑战。选区激光熔化成形Al-Mg-Sc-Zr合金具有强度高、密度低的特点,针对该材料,建立了一种基于裂纹萌生、扩展机制的疲劳寿命分析方法。基于有限元分析建立了不同尺寸、位置裂纹的应力强度因子(SIF)快速分析模型,并基于NASGRO模型进行了裂纹扩展寿命分析,建立了基于缺陷几何特征的裂纹萌生寿命分析模型,最终实现了包含裂纹萌生、扩展2个阶段的疲劳全寿命分析,并与垂直堆积方向(TD)、平行堆积方向(PD)试样的疲劳试验结果进行了对比。结果表明,疲劳寿命试验结果基本位于2倍误差分散带范围内,验证了所提方法的有效性;裂纹萌生主要受缺陷几何特征影响,而裂纹扩展主要受微观组织影响。该方法可为增材制造疲劳寿命评估提供科学依据、手段。

关键词: 激光选区熔化, Al-Mg-Zr-Sc, 裂纹萌生与扩展, 缺陷几何特征, 寿命分析

Abstract:

Additive Manufacturing (AM) has significant application value in the aerospace field due to its characteristics of free-forming and rapid production. However, the fatigue dispersion of materials produced by AM shows considerable variability, making accuratel fatigue life assessment a key challenge in aerospace applications. Selective Laser Melting (SLM) Al-Mg-Sc-Zr alloy exhibits high strength and low density. This paper establishes a fatigue life analysis method based on the mechanisms of crack initiation and propagation for this material. First, a rapid Stress Intensity Factor (SIF) analysis model was developed for cracks with varying sizes and locations based on finite element analysis. Subsequently, the crack propagation life was evaluated using the NASGRO model, and a defect-based crack initiation life model was established. Ultimately, a two-stage fatigue life analysis encompassing both crack initiation and propagation was developed. The analysis results were compared with fatigue test data from Transverse Build Direction (TD) and Parallel Build Direction (PD) samples. The results indicate that the fatigue life text results generally fall within the twofold error band, validating the effectiveness of the proposed method. Crack initiation is primarily influenced by the defect geometric characteristics, while crack propagation is mainly governed by the microstructure. This method provides a scientific basis and means for fatigue life assessment of AM materials.

Key words: selective laser melting, Al-Mg-Sc-Zr, crack initiation and propagation, defect geometric characteristics, life analysis

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