Investigation of beta fleck formation in Ti-17 alloy by directional solidification method

doi:10.1016/j.jmst.2019.12.018

IMR OpenIR

	Investigation of beta fleck formation in Ti-17 alloy by directional solidification method
	Yin, Xuchen 1,2; Liu, Jianrong 2; Wang, Qingjiang 2; Wang, Lei 2
通讯作者	Liu, Jianrong(jrliu@imr.ac.cn)
	2020-07-01
发表期刊	JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
ISSN	1005-0302
卷号	48 页码:36-43
摘要	Beta flecks are one of the most common defects occur in some alpha + beta and beta titanium alloys. In this study, formation of beta flecks in Ti-17 alloy was investigated by directional solidification experiments. Samples were directionally solidified under a constant temperature gradient of 2 x 10(4) K/m and a wide range of withdrawal rates (R) from 3 mm/h to 150 mm/h. We find that macrostructure of the directionally solidified Ti-17 samples can be characterized by "four zones and two lines" after the heat treatment. Profile of the solid-liquid interface transits from planar to cellular to dendritic shape with solidification rate increasing from 3 mm/h to 150 mm/h. The critical rates for planar to cellular (R-c1) transition and cellular to dendritic (R-c2) transition can be well predicted based on the traditional solidification theory. Dark and light contrast areas in macrostructure are directly related to elemental segregation. Dark contrast areas are rich of Cr, Zr but lean of Mo, while no apparent segregation is found in light contrast areas and the mean level of Cr, Zr is lower and Mo is higher in this area than that in dark contrast areas. We conclude that beta-flecks in Ti-17 titanium alloy are induced by segregation of alloying elements with k<1 and their shape and size are determined by solidification conditions. Based on the findings of the present article and other literatures, three types of beta-flecks are proposed and their formation mechanisms are discussed. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
关键词	Titanium Alloy Beta flecks Directional solidification Elemental segregation Microstructure heterogeneity
DOI	10.1016/j.jmst.2019.12.018
收录类别	SCI
语种	英语
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000534323200006
出版者	JOURNAL MATER SCI TECHNOL
引用统计	被引频次：11[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/321006/138897
专题	中国科学院金属研究所
通讯作者	Liu, Jianrong
作者单位	1.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Yin, Xuchen,Liu, Jianrong,Wang, Qingjiang,et al. Investigation of beta fleck formation in Ti-17 alloy by directional solidification method[J]. JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,2020,48:36-43.
APA	Yin, Xuchen,Liu, Jianrong,Wang, Qingjiang,&Wang, Lei.(2020).Investigation of beta fleck formation in Ti-17 alloy by directional solidification method.JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,48,36-43.
MLA	Yin, Xuchen,et al."Investigation of beta fleck formation in Ti-17 alloy by directional solidification method".JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY 48(2020):36-43.