热障涂层对K417G合金高温低周疲劳行为的影响  

Effects of Thermal Barrier Coatings on High Temperature Low Cycle Fatigue Behavior of K417 GAlloy

作　　者：周轶群[1] 佟文伟[1] 刘芳[1] 张开阔[1] 

机构地区：[1]中航工业沈阳发动机设计研究所,沈阳110015

出　　处：《材料工程》2014年第1期19-23,共5页Journal of Materials Engineering

摘　　要：研究了涂覆热障涂层的K417G合金800℃下由应变控制的高温低周疲劳行为,并对其循环应力-应变数据和应变-疲劳寿命数据进行了分析,给出了涂覆热障涂层K417G合金的高温应变疲劳参数。结果表明:K417G合金无涂层和涂覆热障涂层状态下的低周疲劳均属于应力疲劳,以弹性损伤为主;总应变幅较大时,涂覆热障涂层的K417G合金低周疲劳寿命稍优于无涂层的K417G合金。疲劳试样断口的微观分析表明:热障涂层对K417G合金低周疲劳裂纹萌生方式无明显影响;疲劳裂纹通常萌生于疲劳试样的表面或近表面,表现为穿晶扩展。High temperature low cycle fatigue（LCF） behavior of K417G alloy with thermal barrier coatings（TBCs） at 800℃ was investigated under fully reversed total strain-controlled mode.The individual strain fatigue parameters were gained by the analysis of strain-fatigue life and cyclic stressstrain data.The results indicate that the LCF of K417G alloy and K417G alloy with TBCs are stress fatigue,and the primary damage of LCF processing is elastic damage.K417G alloy with TBCs exhibits a longer LCF life than the K417G alloy,especially with higher strain.The SEM observations show that TBCs have little influence on the initiation of LCF cracks of K417G alloy.The LCF cracks initiate predominantly on the surface of specimens or at near surface defects,and the LCF specimens exhibit transgranular propagation.

关 键 词：热障涂层 K417G合金 弹性损伤 低周疲劳行为 过渡疲劳寿命 

分 类 号：TG174.4[金属学及工艺—金属表面处理]