Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy

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	Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy
	E. D. Wu; J. C. Li; J. Zhang; S. C. Wang; G. Xie; B. Chen; G. G. Sun; V. Ji; D. Hughes; T. Pirling
	2008
发表期刊	Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science
ISSN	1073-5623
卷号	39A 期号:13 页码:3141-3148
摘要	The relationship between internal stress and thermomechanical fatigue (TMF) in a Ni-based single-crystal superalloy is studied by neutron and X-ray diffraction. The extents of internal stress, deformation, lattice mismatch, and distortion during TMF are characterized by the determined deviatoric stress invariants and lattice parameters and compared with relevant microstructural information from scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that, in general, the macroscopic stress, plastic deformation, lattice mismatch, and distortion have all increased during TMF. The lattice mismatches of the TMF samples are at a high level, where the values along [100]/[010] are negative, but those along [001] are positive. The tetragonal lattice distortion of the gamma matrix is slightly greater than that of the gamma' precipitates, where the c/a values of the gamma matrix are smaller than 1, but that of the gamma' precipitate larger than 1. The gamma matrix yields and becomes hardened at the initial TMF cycle and gradually loses most of its strength during the earlier TMF cycles, associated with stress relaxation and homogenous deformation. However, the gamma' precipitates yield and become hardened later, bearing the most stress up to the necking of the superalloy. This process is associated with a buildup of stress and significant concentrated and inhomogeneous distribution of deformation in the gamma' precipitate. The residual deformation states of the superalloy and its component phases at the earlier TMF are basically shearing, and only become stretched at a later stage of TMF. The microstructure of the TMF samples shows an initial stage of rafting, where the dislocations are accumulated at the interfaces of the gamma matrix channels, but both dislocation networks and stacking faults are inhomogeneously distributed in the gamma' precipitates.
部门归属	[wu, erdong; li, jinchao; zhang, jun; xie, guang; zhang, jian] chinese acad sci, inst met res, shenyang 110016, peoples r china. [chen, bo; sun, guangai] china acad engn phys, inst nucl phys & chem, mianyang 621900, peoples r china. [ji, vincent] univ paris 11, lemhe icmmo, umr 8182, f-91405 orsay, france. [hughes, darren; pirling, thilo] inst laue langevin, f-38042 grenoble, france.;wu, ed (reprint author), chinese acad sci, inst met res, shenyang 110016, peoples r china;ewu@imr.ac.cn
关键词	Nickel-base Superalloy Beam Electron-diffraction Creep-deformation High-temperature Residual-stresses Lattice Mismatch Elastic Strains Turbine Blade Evolution Gamma'
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WOS记录号	WOS:000260838700012
引用统计	被引频次：8[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/33198
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	E. D. Wu,J. C. Li,J. Zhang,et al. Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy[J]. Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science,2008,39A(13):3141-3148.
APA	E. D. Wu.,J. C. Li.,J. Zhang.,S. C. Wang.,G. Xie.,...&T. Pirling.(2008).Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy.Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science,39A(13),3141-3148.
MLA	E. D. Wu,et al."Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy".Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science 39A.13(2008):3141-3148.