Thermal Stability and Lattice Strain Evolution of High‐Nb‐Containing TiAl Alloy under Low‐Cycle‐Fatigue Loading

作者：Jie Ding, Shuntian Huang, Zhili Dong, Junpin Lin, Yang Ren, Xiaodong Wu, Hui Chang · 发表于：Advanced Engineering Materials · 年份：2021 · DOI：10.1002/adem.202001337 · 被引用次数：15 · 研究领域：Intermetallics and Advanced Alloy Properties、MXene and MAX Phase Materials、Titanium Alloys Microstructure and Properties

The micromechanical behavior and the effect of temperature on the micromechanical mechanism of high‐Nb‐containing TiAl alloy during low‐cycle fatigue still remain uncertain. Herein, in situ and ex situ synchrotron‐based high‐energy X‐ray (HEXRD) experiment results reveal that the γ and ω o phases suffer compressive lattice strains but the lattice strain in the α 2 phase evolves from tensile to compressive during low‐cycle fatigue at 900 °C. In addition, the three phases suffer compressive lattice strains during cooling to room temperature, which could result in larger compressive lattice strains in γ and ω o phases and the change of the lattice strain state in the α 2 phase. The peak‐broadening results show γ recrystallization is dominant in the interrupted low‐cycle‐fatigue samples, whereas inhomogeneous deformation occurs in the failed low‐cycle‐fatigue samples. The performed synchrotron diffraction experiments offer a deeper insight into the phase transformations and micromechanism of TiAl alloy during low‐cycle fatigue.