摘要
热障涂层(TBCs)在提升镍基高温合金抗高温氧化性能方面已有充分研究,但其在高温低周疲劳(LCF)载荷下的力学行为,尤其是随应力水平演变的“双刃剑”作用机制仍不明确,制约了TBCs在航空发动机涡轮盘等关键承力部件中的安全设计与应用。为此,针对涂覆TBCs的IN718合金,在650℃(典型涡轮盘考核温度)下开展LCF试验。结果表明,涂层对疲劳性能的影响具有显著的应力阈值效应:在550 MPa的应力下,涂层通过界面结合与残余压应力抑制裂纹萌生,疲劳寿命提升43.4%;当应力超过580 MPa后,涂层缺陷成为裂纹源,疲劳寿命下降达70.9%。断口分析表明,低应力下涂层可调控裂纹扩展与位错分布,提高疲劳性能;高应力下涂层开裂并沿界面扩展,导致早期失效。SEM与TEM微观分析进一步揭示了涂层在不同应力下的界面行为与失效机理。研究结果为面向疲劳工况的热障涂层设计与可靠性评价提供了关键理论依据与数据支撑。
The role of thermal barrier coatings(TBCs)in enhancing the high‑temperature oxidation resistance of nickel‑based superalloys has been extensively studied.However,their mechanical behavior under high‑temperature low‑cycle fatigue(LCF)loading,particularly the dual‑effect mechanism evolving with stress levels,remains unclear,which limits the safe design and application of TBCs in key load‑bearing components such as aero‑engine turbine disks.Therefore,LCF tests were conducted on IN718 alloy coated with TBCs at 650℃(a typical assessment temperature for turbine disks).The results show that the influence of the coating on fatigue performance exhibits a significant stress threshold effect:At a stress of 550 MPa,the coating inhibits crack initiation through interfacial bonding and residual compressive stress,improving fatigue life by 43.4%;when the stress exceeds 580 MPa,coating defects become crack sources,reducing fatigue life by up to 70.9%.Fracture analysis indicates that at low stress,the coating can regulate crack propagation and dislocation distribution,improving fatigue performance;at high stress,the coating cracks and propagates along the interface,leading to early failure.Further SEM and TEM microscopic analyses have revealed the interfacial behavior and failure mechanisms of the coating under varying stresses.The research results provide key theoretical basis and data support for the design and reliability evaluation of thermal barrier coatings for fatigue service conditions.
作者
毛剑峰
蔡金晨
蔡友权
陈明亚
程东岳
徐遣
MAO Jianfeng;CAI Jinchen;CAI Youquan;CHEN Mingya;CHENG Dongyue;XU Qian(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China;Taizhou Institute,Zhejiang University of Technology,Taizhou 318014,China;Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou 215004,China;Zhejiang Academy of Special Equipment Science,Hangzhou 310020,China)
出处
《压力容器》
北大核心
2025年第12期1-9,共9页
Pressure Vessel Technology
基金
国家自然科学基金资助项目(51975526,51505425)
国家重点研发计划项目(2018YFC0808800)。
