航空学报 > 2026, Vol. 47 Issue (5): 432400-432400   doi: 10.7527/S1000-6893.2025.32400

镍基单晶飞秒激光制造气膜孔疲劳断裂行为

李飞1(), 温志勋2,3, 罗磊1, 岳珠峰2,3, 刘智名2   

  1. 1.哈尔滨工业大学 能源科学与工程学院,哈尔滨 150001
    2.西北工业大学 力学与交通运载工程学院,西安 710072
    3.西北工业大学 清洁高效透平动力装备全国重点实验室,西安 710072
  • 收稿日期:2025-06-09 修回日期:2025-07-04 接受日期:2025-08-12 出版日期:2025-10-10 发布日期:2025-10-09
  • 通讯作者: 李飞 E-mail:lifei24@hit.edu.cn
  • 基金资助:
    国家自然科学基金(52375158);国家自然科学基金(52505147);国家资助博士后研究人员计划(GZB20240953);中国博士后科学基金(2024M754201)

Fatigue fracture behavior of femtosecond-laser-processed film cooling holes in nickel-based single-crystal superalloys

Fei LI1(), Zhixun WEN2,3, Lei LUO1, Zhufeng YUE2,3, Zhiming LIU2   

  1. 1.School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China
    2.School of Mechanics and Transportation Engineering,Northwestern Polytechnical University,Xi’an 710072,China
    3.State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment,Northwestern Polytechnical University,Xi’an 710072,China
  • Received:2025-06-09 Revised:2025-07-04 Accepted:2025-08-12 Online:2025-10-10 Published:2025-10-09
  • Contact: Fei LI E-mail:lifei24@hit.edu.cn
  • Supported by:
    National Natural Science Foundation of China(52375158);Postdoctoral Fellowship Program of CPSF(GZB20240953);China Postdoctoral Science Foundation(2024M754201)

摘要:

镍基单晶涡轮叶片上通常布置数百个直径在0.2~0.8 mm之间的气膜孔,气膜孔的存在破坏了涡轮叶片结构完整性,在高温疲劳载荷下成为叶片失效断裂的多发部位。针对气膜孔制造初始损伤与疲劳断裂行为强相关的问题,以镍基单晶合金飞秒激光制造气膜孔试样开展疲劳断裂行为研究。首先,采用流体动力学方法建立了飞秒激光三维螺旋制孔仿真模型,获取制孔过程孔型演化规律;然后从几何、微观结构和力学性能方面对气膜孔表面完整性进行分析,气膜孔孔型平均锥度约为0.19°,孔边热损伤区的最大深度约为18 μm,且发生严重氧化,孔边残余应力最大值为463 MPa。紧接着,对气膜孔试样进行980 ℃下疲劳试验,从试样断口中发现裂纹起源于孔壁热影响区,随后裂纹面以近似逆时针旋转约6°的椭圆轮廓沿着垂直于载荷的方向扩展直至断裂。最后,根据飞秒激光制造气膜孔疲劳断裂行为提出了基于增量塑性和构形力理论的M积分裂纹扩展驱动力,并在此基础上构建了气膜孔疲劳裂纹扩展率与有效裂纹扩展驱动力之间的有效函数描述模型。

关键词: 镍基单晶合金, 气膜孔, 飞秒激光, 初始制造损伤, 裂纹扩展

Abstract:

Hundreds of film-cooling holes with a diameter ranging from 0.2 mm to 0.8 mm are usually arranged on nickel-based single-crystal turbine blades. The existence of these film-cooling holes impairs the structural integrity of the turbine blades, making them high-risk locations for blade failure and fracture under high-temperature fatigue loads. To address the issue that the initial manufacturing defects of film-cooling holes are strongly correlated with their fatigue fracture behavior, a study on the fatigue fracture behavior was conducted using nickel-based single-crystal alloy specimens with film-cooling holes fabricated by femtosecond laser. Firstly, a three-dimensional spiral hole-drilling simulation model for femtosecond laser was established based on the hydrodynamic method to obtain the evolution law of hole morphology during the drilling process. Subsequently, the surface integrity of the film-cooling holes was analyzed from three aspects: geometry, microstructure, and mechanical properties. The average taper of the film-cooling holes was approximately 0.19°, the maximum depth of the thermal damage zone near the hole edges was about 18 μm with severe oxidation observed, and the maximum residual stress at the hole edges reached 463 MPa. Subsequently, fatigue tests were conducted on the specimens with film-cooling holes at 980 °C. Fracture analysis revealed that cracks originated from the heat-affected zone of the hole walls and propagated in an elliptical contour with an approximate 6° counterclockwise rotation until fracture occurred. Finally, based on the fatigue fracture behavior of film-cooling holes fabricated by femtosecond laser, an M-integral crack propagation driving force was proposed, which is based on incremental plasticity and configurational force theory. On this basis, an effective functional model describing the relationship was constructed between the fatigue crack growth rate of film-cooling holes and the effective crack propagation driving force.

Key words: nickel-based single-crystal superalloys, film-cooling hole, femtosecond lasers, initial manufacturing damage, crack propagation

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