MICROSTRUCTURE AND MICROSEGREGATION IN A Ni-BASED SINGLE CRYSTAL SUPERALLOY DIRECTIONALLY SOLIDIFIED UNDER HIGH THERMAL GRADIENT

doi:10.3724/SP.J.1037.2009.00419

IMR OpenIR

	MICROSTRUCTURE AND MICROSEGREGATION IN A Ni-BASED SINGLE CRYSTAL SUPERALLOY DIRECTIONALLY SOLIDIFIED UNDER HIGH THERMAL GRADIENT
	Liu Gang 2; Liu Lin 2; Zhao Xinbao 2; Zhang Weiguo 2; Jin Tao 1; Zhang Jun 2; Fu Hengzhi 2
通讯作者	Liu Gang(muchengliu@126.com)
	2010-01-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	46 期号:1 页码:77-83
摘要	In order to understand the effect of high thermal gradient on the microsegregation of refractory elements in Ni-based superalloys, a Ni-based single crystal superalloy containing 4% Re (mass fraction) was prepared by dual heating zone melting and liquid-metal cooling (LMC) directional solidification technique. Comparing with the traditional high rate solidification (HRS) method with thermal gradient G=20-40 K/cm, withdrawal rate V=50-100 mu m/s and primary dendritic arm spacing lambda(1)=200-400 mu m, this technique can significantly increase the thermal gradient (up to 238 K/cm) and withdrawal rates (up to 500 mu m/s). Planar-like and cellular-like solid-liquid interfaces, coarse dendrite and fine dendrite were sequentially obtained with increasing withdrawal rates. Under the condition of G=238 K/cm and V=500 mu m/s, the primary dendritic arm spacing lambda(1) and the mean size of gamma' precipitates (in dendrite core) obviously decreased to 61.3 and 0.04 mu m, respectively. In addition, the microsegregation increased initially and then decreased with increasing withdrawal rate, especially for the microsegregations of W and Re. EPMA line scan indicated that solid-back diffusion has an obvious influence on the microsegregation for the fine dendrite structure under high thermal gradient directional solidification.
关键词	Ni-based single crystal superalloy high thermal gradient microsegregation microstructure
资助者	National Natural Science Foundation of China ; National High Technical Research and Development Program of China
DOI	10.3724/SP.J.1037.2009.00419
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[50771081] ; National Natural Science Foundation of China[50827102] ; National High Technical Research and Development Program of China[2007AA03Z552]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000274823200013
出版者	SCIENCE PRESS
引用统计	被引频次：17[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/321006/101012
专题	中国科学院金属研究所
通讯作者	Liu Gang
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 2.NW Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China
推荐引用方式 GB/T 7714	Liu Gang,Liu Lin,Zhao Xinbao,et al. MICROSTRUCTURE AND MICROSEGREGATION IN A Ni-BASED SINGLE CRYSTAL SUPERALLOY DIRECTIONALLY SOLIDIFIED UNDER HIGH THERMAL GRADIENT[J]. ACTA METALLURGICA SINICA,2010,46(1):77-83.
APA	Liu Gang.,Liu Lin.,Zhao Xinbao.,Zhang Weiguo.,Jin Tao.,...&Fu Hengzhi.(2010).MICROSTRUCTURE AND MICROSEGREGATION IN A Ni-BASED SINGLE CRYSTAL SUPERALLOY DIRECTIONALLY SOLIDIFIED UNDER HIGH THERMAL GRADIENT.ACTA METALLURGICA SINICA,46(1),77-83.
MLA	Liu Gang,et al."MICROSTRUCTURE AND MICROSEGREGATION IN A Ni-BASED SINGLE CRYSTAL SUPERALLOY DIRECTIONALLY SOLIDIFIED UNDER HIGH THERMAL GRADIENT".ACTA METALLURGICA SINICA 46.1(2010):77-83.