文献类型：期刊文献

英文题名：Quasi-in-Situ Observation and Analysis of Grain Boundary Evolution of Gh4169 Nickel-Based Superalloy During Micro-Strain Stage of Thermal Deformation

作者：Ling, Min Liang, Yilong

第一作者：凌敏;Ling, Min

机构：[1] College of Materials and Metallurgy, Guizhou University, Guiyan, 550025, China; [2] Key Laboratory for Mechanical Behavior and Microstructure of Materials of Guizhou Province, Guiyan, 550025, China; [3] National and Local Joint Engineering Laboratory for High-performance Metal Structure Material and Advanced Manufacturing Technology, Guiyan, 550025, China; [4] School of Materials and Energy Engineering, Guizhou Institute of Technology, Guiyang, 550003, China

第一机构：College of Materials and Metallurgy, Guizhou University, Guiyan, 550025, China

年份：2023

外文期刊名：SSRN

收录：EI(收录号：20230034545)

语种：英文

外文关键词：Dynamic recrystallization - Nickel - Nickel alloys - Precipitation (chemical) - Strain rate - Superalloys - Textures - Thermal Engineering - Transmission electron microscopy

摘要：A systematical investigation was conducted to explore the microstructure evolution of grain boundaries in the micro-strain stage during the thermal deformation of a precipitation-hardened nickel-based superalloy, GH4169. A quasi-in-situ EBSD (electron backscatter diffraction) was approach was used for observation, and at a temperature of 1,100 °C, a continuous strain uniaxial compression experiment was conducted at a strain rate of 0.1 s-1. We observed the development of the grain boundary structure and the grain boundary deformation. The experimental findings revealed that GH4169 experienced locally inhomogeneous thermal deformation in the micro-strain stage, along with the simultaneous occurrence of grain boundary slip, grain rotation, and grain boundary migration, exhibiting microstructural diversity. The grain boundary of > 30° was found from the statistical examination of grain boundary structure for the purpose of easy migration. The grain boundary structure changed continuously as a result of the random movement of high-angle grain boundaries. Twin grains displayed a stable structure during the migration of grain boundaries, and their content indicated a considerable decrease as the strain increased. This provides a basis for directing the design of grain boundary engineering since it suggests that twin boundaries are easier to migrate during thermal deformation. In addition, dynamic recrystallization was not found throughout the entire micro-strain stage and a / micro-texture was observed, which is compatible with common dislocation slip in face-centered cubic crystals. Then, on the basis of the transmission electron microscope images of the microstructure, the numerous forms of grain boundary deformation were rationally explained from the standpoint of the relation mechanisms among grain boundaries and dislocations. Finally, the synergistic mechanism of grain boundary slip and migration is established as the primary mechanism of thermal deformation in the micro-strain stage. ? 2023, The Authors. All rights reserved.