Low-cycle Fatigue Behavior of Ni-based Superalloy GH586 with Laser Shock Processing

• Published in: Journal of Wuhan University of Technology. Materials science edition Vol. 32; no. 5; pp. 1186 - 1192
• Main Author: 曹将栋;ZHANG Junsong;花银群;RONG Zhen;CHEN Ruifang;YE Yunxia
• Format: Journal Article
• Language: English
• Published: Wuhan Wuhan University of Technology 01.10.2017; Springer Nature B.V
• Subjects: Chemistry and Materials Science; Compressive properties; Crack initiation; Crack propagation; Deformation mechanisms; Dimpling; Dislocation density; Fatigue cracks; Fatigue failure; Fatigue life; Fracture mechanics; GH586合金; Laser shock processing; Low cycle fatigue; Materials Science; Metallic Materials; Microstructure; Nickel base alloys; Plastic deformation; Residual stress; Scanning electron microscopy; Striations; Superalloys; Tangling; Tearing; 低周; 扫描电子显微镜; 激光冲击处理; 疲劳行为; 疲劳裂纹扩展; 透射电子显微镜; 镍基合金; laser shock processing; fatigue fracture; microstructure; Ni-based superalloy
• ISSN: 1000-2413; 1993-0437
• DOI: 10.1007/s11595-017-1729-0

Low-cycle fatigue behavior of Ni-based superalloy GH586 with laser shock processing（LSP） was investigated. The residual stress of the specimens treated with LSP was assessed by X-ray diffraction method. The microstructure and fracture morphology were characterized by using an optical microscope（OM）, a scanning electron microscope（SEM）, and a transmission electron microscope（TEM）. The results indicated that the maximum residual compressive stress was at about 1 mm from the shocking spot center, where the residual compressive stress was slightly lower. High density tangling dislocations, dislocation walls, and dislocation cells in the microstructure of the specimens treated with LSP effectively prevented fatigue cracks propagation. The fatigue life was roughly twice as long as that of the specimens without LSP. The fatigue crack initiation（FCI） in specimens treated with LSP was observed in the lateral section and the subsurface simultaneously. The fatigue striation in the fracture treated with LSP was narrower than that in the untreated specimens. Moreover, dimples with tear ridges were found in the fatigued zones of the LSP treated specimens, which would be caused by severe plastic deformation.