Investigation on freckle formation and evolution of single-crystal nickel-based superalloy specimens with different thicknesses and abrupt cross-section changes

doi:10.1016/j.jallcom.2019.07.045

IMR OpenIR

	Investigation on freckle formation and evolution of single-crystal nickel-based superalloy specimens with different thicknesses and abrupt cross-section changes
	Han, Dongyu 1,2; Jiang, Weiguo 1; Xiao, Jiuhan 1,2; Li, Kaiwen 1; Lu, Yuzhang 1; Zheng, Wei 1; Zhang, Shaohua 1; Lou, Langhong 1
通讯作者	Jiang, Weiguo(wgjiang@imr.ac.cn)
	2019-10-15
发表期刊	JOURNAL OF ALLOYS AND COMPOUNDS
ISSN	0925-8388
卷号	805 页码:218-228
摘要	The freckle formation and evolution in directionally solidified single-crystal specimens with different thicknesses and abruptly expanding rectangular cross-section were investigated at different withdrawal rates. The microstructure was studied by optical microscope (OP) and scanning electron microscope (SEM), and the crystallographic orientation in freckle areas was characterized by electron backscattered diffraction (EBSD). The experimental results showed that the freckle was the most severe in specimens with a thickness of 10 mm at the same withdrawal rate, and the freckle chain was observed to form below an abruptly expanding cross-section ended at the expanding step. It was found that freckles formed exclusively on the edges of casting facing the central sprue of the shell mould. Findings reveal that freckles tend to form at the highest position of the mushy zone, mainly due to the thermosolutal convection and the radial flow caused by feeding behavior in the mushy zone. The freckle formation is pronounced at a low withdrawal rate, and can further generate stray grains. (C) 2019 Elsevier B.V. All rights reserved.
关键词	Nickel-based superalloy Crystal growth Freckle Abruptly expanding cross-section
资助者	National Natural Science Foundation of China ; National Key Research and Development Program of China
DOI	10.1016/j.jallcom.2019.07.045
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[51674235] ; National Key Research and Development Program of China[2017YFB0702904]
WOS研究方向	Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Chemistry, Physical ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000482184100026
出版者	ELSEVIER SCIENCE SA
引用统计	被引频次：25[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/321006/135170
专题	中国科学院金属研究所
通讯作者	Jiang, Weiguo
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Han, Dongyu,Jiang, Weiguo,Xiao, Jiuhan,et al. Investigation on freckle formation and evolution of single-crystal nickel-based superalloy specimens with different thicknesses and abrupt cross-section changes[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2019,805:218-228.
APA	Han, Dongyu.,Jiang, Weiguo.,Xiao, Jiuhan.,Li, Kaiwen.,Lu, Yuzhang.,...&Lou, Langhong.(2019).Investigation on freckle formation and evolution of single-crystal nickel-based superalloy specimens with different thicknesses and abrupt cross-section changes.JOURNAL OF ALLOYS AND COMPOUNDS,805,218-228.
MLA	Han, Dongyu,et al."Investigation on freckle formation and evolution of single-crystal nickel-based superalloy specimens with different thicknesses and abrupt cross-section changes".JOURNAL OF ALLOYS AND COMPOUNDS 805(2019):218-228.