南京航空航天大学学报2025，Vol.57Issue(4)：601-609,9.DOI:10.16356/j.1005-2615.2025.04.002
温度对第四代粉末高温合金低周疲劳变形行为的影响
Effect of Temperature on Low-Cycle Fatigue Deformation Behavior of a Fourth-Generation Powder Metallurgy Superalloy
摘要
Abstract
This study systematically investigates the influence of temperature on the low-cycle fatigue(LCF)deformation mechanisms of the fourth-generation powder metallurgy(PM)superalloy FGH4108.Strain-controlled fatigue tests were conducted at temperatures ranging from 400℃to 850℃,in combination with microstructural characterization techniques including scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).The evolution of the fatigue response from cyclic hardening to softening under temperature control was elucidated.The results show that FGH4108 exhibits significant cyclic hardening behavior at temperatures up to 600℃,whereas cyclic softening becomes dominant above 700℃,with the most pronounced effect observed at 850℃.Fracture mode transitions from transgranular to intergranular with increasing temperature,accompanied by a change in deformation mechanism from dislocation accumulation in the matrix to a combined mechanism of γ′precipitate shearing,stacking fault formation,and twinning.TEM observations revealed that the γ′ phase exhibits reduced thermal stability at elevated temperatures,with localized stacking faults and γ′ shearing features observed.EBSD analysis indicated that the distribution of intragranular local misorientation remains relatively stable between 600℃and 850℃,suggesting a limited influence of temperature on overall dislocation density.These findings provide insights into the temperature-dependent fatigue behavior of FGH4108 and offer theoretical guidance for performance evaluation and design optimization of next-generation PM superalloys.关键词
粉末高温合金/低周疲劳/循环变形/位错/变形机理Key words
powder metallurgy superalloy/low-cycle fatigue/cyclic deformation/dislocation/deformation mechanism分类
数理科学引用本文复制引用
金易璇,江荣,李张辉,张强,刘建涛,宋迎东..温度对第四代粉末高温合金低周疲劳变形行为的影响[J].南京航空航天大学学报,2025,57(4):601-609,9.基金项目
航空发动机及燃气轮机基础科学中心重点项目(P2022-B-Ⅲ-007-001) （P2022-B-Ⅲ-007-001）
国家科技重大专项(2017-Ⅵ-0009-0079) （2017-Ⅵ-0009-0079）
江苏省自然科学基金(BK20220136). （BK20220136）
