GH4169合金不同孔形气膜冷却孔疲劳性能对比分析  

Fatigue Property Investigation of GH4169 Alloy Film Cooling Holes With Different Shapes

作　　者：左杨杰 杨艳静[2] 陈伟 徐全勇[3] Zuo Yangjie;Yang Yanjing;Chen Wei;Xu Quanyong(School of Aeronautics and Astronautics,Sichuan University,Chengdu 610065,China;Beijing Satellite Environmental Engineering Research Institute,Beijing 100094,China;Institute of Aero Engine,Tsinghua University,Beijing 100084,China)

机构地区：[1]四川大学空天科学与工程学院,四川成都610065 [2]北京卫星环境工程研究所,北京100094 [3]清华大学航空发动机研究院,北京100084

出　　处：《稀有金属材料与工程》2022年第6期2224-2230,共7页Rare Metal Materials and Engineering

基　　金：航天创新基金(CAST-BISEE2019-017)。

摘　　要：气膜冷却孔是航空航天高温部件常见冷却设计,但属于典型结构疲劳危险点。为了优化气膜冷却孔热-机械性能,本研究通过疲劳试验和有限元建模分析,研究GH4169合金相同底孔尺寸下的气膜冷却孔疲劳性能。研究表明:相同底孔直径下,90°圆孔疲劳寿命远低于倾斜圆孔、扇形孔和扇形后倾孔;相同孔倾角下,孔形对疲劳寿命影响较小;90°圆孔发生单断口疲劳断裂,断口与加载方向基本垂直,而倾斜圆孔、扇形孔、扇形后倾孔在孔根部附近发生疲劳断裂,断口向孔轴方向倾斜,除主断口外在孔根部均出现亚断口;90°圆孔断口疲劳裂纹在孔壁中间萌生,而倾斜圆孔和扇形孔疲劳裂纹在孔口部位萌生,且呈现多源萌生特征;裂纹萌生区平整光滑,随着裂纹扩展断口表面韧窝明显增多;孔轴倾角和孔口形状对孔周应力分布及最大应力水平具有显著影响。Film cooling is a common cooling design in aerospace high temperature components,but it is also a typical fatigue risk point of the whole structure.In order to optimize the designs of film cooling holes,the fatigue properties of GH4169 alloy film cooling holes with different shapes were investigated by fatigue test and finite element model analysis.Results show that the fatigue life of the circular shaped hole is obviously lower than those of both the oval shaped hole and the dust-pan shaped hole,and the hole shape exhibits a few influence on the fatigue life of the specimens corresponding to the same skew angle of holes.The specimens of the 90°circular shaped hole fail with only one fracture surface,and the fracture surface is perpendicular to the loading direction.However,the specimens of the oval shaped hole and the dust-pan shaped hole fail with master fracture surface and slave master fracture surface,and the fracture surface is along the hole axis direction.Fatigue crack initiation occurs at the middle region of the 90°circular shaped hole,while fatigue crack initiation occurs at both the entrance and the exit of the oval shaped and the dust-pan shaped hole.The crack initiation zone is flat and smooth,moreover,more dimples are observed on the fracture surface with fatigue crack propagating.Both the skew angle of holes and the shape hole orifice exhibit significant influence on the stress distribution and the peak stress of the hole under quasi-static loading.

关 键 词：高温合金 气膜冷却孔 疲劳性能 优化设计 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG113.255[金属学及工艺—金属材料]