Generation mechanism and motion behavior of sliver defect in single crystal Ni-based superalloy

doi:10.1016/j.jmst.2022.07.045

IMR OpenIR

	Generation mechanism and motion behavior of sliver defect in single crystal Ni-based superalloy
	Xia, Huxiang 1; Yang, Yanhong 2; Feng, Qiushui 1; Xu, Qingyan 1; Dong, Hongbiao 3; Liu, Baicheng 1
通讯作者	Xu, Qingyan(scjxqy@tsinghua.edu.cn)
	2023-02-20
发表期刊	JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
ISSN	1005-0302
卷号	137 页码:232-246
摘要	Sliver is a common but easily neglected defect in single crystal Ni-based superalloy castings. To date, there is still no unified viewpoint on its formation mechanism and generation causes. In this work, the orientation discontinuity and motion behavior of sliver defects were studied through experiments and numerical simulations. The ultrathin wedge-shaped specimen containing the grain boundary of the sliver and the matrix was prepared at the initial position of the sliver defect for the observation of equal thick-ness fringes. The discontinuity of equal thickness fringes on both sides of the grain boundary was ob-served through a transmission electron microscope, which directly confirms the abrupt change in the orientation between the sliver and matrix from the nanoscale. The crystal lattices at the smooth area and the bulging area of the grain boundary were found to have unusually different arrangements. The irregular lattice arrangement at the bulging area shows that the grain boundary has experienced high -stress deformation. Statistical results of sliver orientation deviation with a further composition analysis show the micro protuberance of the mold shell has a noticeable inductive effect on the sliver generation. Furthermore, a self-developed three-dimensional phase-field simulation model coupled with the spatial topology algorithm is established to simulate the orientation deflection behavior and orientation devia-tion threshold of fractured dendrites. The simulation results indicated that there is an upper limit of the cross-section solid fraction at the fracture position for the motion of the fractured dendrites. When the cross-section solid fraction at the fracture position is higher than this upper limit, it will be difficult to produce large deviation slivers due to the structural limitation of surrounding dendrites. This upper limit does not change with the solidification temperature gradient.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
关键词	Single crystal Ni-based superalloys Directional solidification Sliver defect Phase -field simulation
资助者	National Science and Technology Major Project
DOI	10.1016/j.jmst.2022.07.045
收录类别	SCI
语种	英语
资助项目	National Science and Technology Major Project ; [2017-V I -0 0 03-0 073] ; [2017-VII -0 0 08-0101]
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000876733000005
出版者	JOURNAL MATER SCI TECHNOL
引用统计	被引频次：6[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/321006/176467
专题	中国科学院金属研究所
通讯作者	Xu, Qingyan
作者单位	1.Tsinghua Univ, Sch Mat Sci & Engn, Key Lab Adv Mat Proc Technol MOE, Beijing 100084, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shi Changxu Innovat Ctr Adv Mat, Shenyang 110016, Peoples R China 3.Univ Leicester, Sch Engn, Leicester LE1 7RH, England
推荐引用方式 GB/T 7714	Xia, Huxiang,Yang, Yanhong,Feng, Qiushui,et al. Generation mechanism and motion behavior of sliver defect in single crystal Ni-based superalloy[J]. JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,2023,137:232-246.
APA	Xia, Huxiang,Yang, Yanhong,Feng, Qiushui,Xu, Qingyan,Dong, Hongbiao,&Liu, Baicheng.(2023).Generation mechanism and motion behavior of sliver defect in single crystal Ni-based superalloy.JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,137,232-246.
MLA	Xia, Huxiang,et al."Generation mechanism and motion behavior of sliver defect in single crystal Ni-based superalloy".JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY 137(2023):232-246.