摘要
针对单晶气冷涡轮叶片的服役载荷特征,以镍基单晶高温合金DD6为对象,设计开展了薄壁圆管试样热机械疲劳(TMF)试验。结果表明:DD6变形响应呈现出明显的TMF棘轮效应,且与相位角、机械载荷水平等密切相关;在相同载荷条件下,同相(IP)TMF寿命总是明显短于反相(OP)。引入高温保载时间或增大机械载荷均会引起棘轮应变的明显增加,缩短结构寿命。结合断口和纵向切片分析,识别了不同载荷条件下影响单晶寿命的关键损伤因素,其中IP TMF主导损伤机理为蠕变和疲劳,而OP TMF主导损伤机理为氧化和疲劳。
According to the service loads experienced by air cooled single crystal turbine blades,thermomechanical fatigue(TMF)experiments were designed and conducted on thinwalled tube specimens made of nickel based single crystal superalloy DD6.The results indicated that the deformation response of DD6 exhibited remarkable ratcheting effect,which was closely related to the phase angle and mechanical loading;and the lifetime of in phase(IP)TMF under all experiment conditions were shorter than that of out of phase(OP)TMF.Either introducing dwell time at peak temperature or increasing mechanical load led to more ratcheting strains and fewer failure cycles.Based on the metallographic examination on fracture surface and longitudinal section of specimens,the critical life-limiting factors underdifferent load conditions were identified.Creepage and fatigue dominate in the competing damage mechanisms for IP TMF,while oxidation and fatigue dominate for OP TMF.
作者
荆甫雷
蒋康河
张斌
胡殿印
王荣桥
JING Fulei;JIANG Kanghe;ZHANG Bin;HU Dianyin;WANG Rongqiao(Aero Engine Academy of China, Aero Engine Corporation of China,Beijing 101304,China;Hunan Aviation Powerplant Research Institute, Aero Engine Corporation of China,Zhuzhou Hunan 412000,China;School of Energy and Power Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100191,China)
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2018年第12期2965-2971,共7页
Journal of Aerospace Power
基金
国家自然科学基金(51375031)
航空科学基金(2015ZBN3004)
关键词
单晶高温合金
热机械疲劳
同相
反相
棘轮效应
损伤
single crystal superalloy
thermomechanical fatigue
in phase
out of phase
ratcheting effect
damage
