High temperature cyclic deformation and fatigue life prediction for dissimilar friction welding of superalloy

研究了铸造多晶MAR-M247与锻造IN718合金异种摩擦焊接高温合金接头在低周和热机械疲劳载荷下的高温疲劳强度和循环变形行为，并与母材进行了比较。试验结果表明，试验条件和加载方式对异种节点的寿命有显著影响。不仅生命本身，而且失效位置和机构对加载方式都很敏感。根据摩擦焊接头的宏观弹性随动机制和微观组织的不均匀性，讨论了加载方式和试验条件对断裂行为的影响。

The high temperature fatigue strengths and cyclic deformation behavior of the dissimilar friction welded superalloys joint between the cast polycrystalline Mar-M247 and the forged IN718 alloys were investigated under low cycle and thermo-mechanical fatigue loadings, in comparison with those of the base metals. The experiments showed that the lives of the dissimilar joints were significantly influenced by the test conditions and loading modes. Not only the lives themselves but also the failure positions and mechanisms were sensitive to the loading mode. The fracture behaviors depending on the loading modes and test conditions were discussed, based on the macroscopic elastic follow-up mechanism and the microstructural inhomogeneity in the friction weld joint.