在高温状态下,镍基单晶超合金的变形、损伤及断裂分析中,孔洞的长大都起着主要的作用。本研究进行了系列的蠕变、疲劳及热机械疲劳(TMF)试验。对试件的断面进行的 SEM 观察表明,所有的断面都是有许多小断面构成,在断面的中心,至少有一...在高温状态下,镍基单晶超合金的变形、损伤及断裂分析中,孔洞的长大都起着主要的作用。本研究进行了系列的蠕变、疲劳及热机械疲劳(TMF)试验。对试件的断面进行的 SEM 观察表明,所有的断面都是有许多小断面构成,在断面的中心,至少有一个孔洞。孔洞的尺寸与加载的条件相关。使用晶体塑性有限元程序对单胞模型进行分析,模拟孔洞的长大规律。给出了蠕变和弹塑性两种条件下的模拟结果及不同的晶体取向对孔穴长大的影响结果。对孔洞长大的有限元分析有助于对实验结果的理解。展开更多
Thermal-mechanical fatigue（TMF）is the primary cause of failure of nickel-based single crystal turbine blades.TMF experiments have been performed on the critical section which is subjected to the most serious damage ...Thermal-mechanical fatigue（TMF）is the primary cause of failure of nickel-based single crystal turbine blades.TMF experiments have been performed on the critical section which is subjected to the most serious damage and determined by numerical calculation combined with service failure experience.An experimental system including the loading,heating,air cooling,water cooling,and control subsystems,is constructed to satisfy the TMF experimental requirements.This experimental system can simulate the stress feld,temperature feld,air cooling process,and TMF spectrum on the critical section under service conditions in a laboratory environment.A metal loading device and a new induction coil are developed to achieve the required stress and temperature distributions on the critical section,respectively.TMF experimental results have indicated that cracks initiated at the trailing edge of the suction surface on the critical section.Based on these experiments,life prediction and failure analysis of hollow single crystal turbine blades can be investigated.展开更多
基金Natural Science Foundation of China (50005016, 50375124), Natural Science Foundation of Shaanxi Province and China aviation foundation (00B53010, 03B53003) as well as the Yangtze River foundation.
文摘在高温状态下,镍基单晶超合金的变形、损伤及断裂分析中,孔洞的长大都起着主要的作用。本研究进行了系列的蠕变、疲劳及热机械疲劳(TMF)试验。对试件的断面进行的 SEM 观察表明,所有的断面都是有许多小断面构成,在断面的中心,至少有一个孔洞。孔洞的尺寸与加载的条件相关。使用晶体塑性有限元程序对单胞模型进行分析,模拟孔洞的长大规律。给出了蠕变和弹塑性两种条件下的模拟结果及不同的晶体取向对孔穴长大的影响结果。对孔洞长大的有限元分析有助于对实验结果的理解。
文摘Thermal-mechanical fatigue（TMF）is the primary cause of failure of nickel-based single crystal turbine blades.TMF experiments have been performed on the critical section which is subjected to the most serious damage and determined by numerical calculation combined with service failure experience.An experimental system including the loading,heating,air cooling,water cooling,and control subsystems,is constructed to satisfy the TMF experimental requirements.This experimental system can simulate the stress feld,temperature feld,air cooling process,and TMF spectrum on the critical section under service conditions in a laboratory environment.A metal loading device and a new induction coil are developed to achieve the required stress and temperature distributions on the critical section,respectively.TMF experimental results have indicated that cracks initiated at the trailing edge of the suction surface on the critical section.Based on these experiments,life prediction and failure analysis of hollow single crystal turbine blades can be investigated.
