A study of epitaxial growth behaviors of equiaxed alpha phase at different cooling rates in near alpha titanium alloy

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	A study of epitaxial growth behaviors of equiaxed alpha phase at different cooling rates in near alpha titanium alloy
	Gao, Xiongxiong; Zeng, Weidong; Zhang, Saifei; Wang, Qingjiang; Zeng, WD (reprint author), Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China.
	2017
发表期刊	ACTA MATERIALIA
ISSN	1359-6454
卷号	122 页码:298-309
摘要	The epitaxial growth behaviors of equiaxed primary alpha phase (alpha(p)) at different cooling rates (150-0.15 degrees C/s) in a near alpha titanium alloy Ti60 were studied by optical micrograph, back scattered electron (BSE) images, high-resolution electron backscatter diffraction technique (EBSD) and electron probe micro-analysis (EPMA). Microstructural observations indicated that the size of alpha(p) significantly increased with decreasing cooling rate. The rim-alpha phase observed by BSE image, which formed at the periphery of ap during cooling and has an identical crystallographic orientation to the interior region of alpha(p) analyzed by Kikuchi diffraction patterns, is considered to be evidence of epitaxial growth of alpha(p). EBSD analysis also showed that ap preferentially grew extending for a distance along the WO boundary resulting in extension-alpha phase from alpha(p). The EPMA confirmed that contrast difference in BSE image within alpha(p) is caused by the difference in composition. The further microanalysis of local composition indicated that epitaxial growth during continuous cooling is mainly controlled by the diffusional redistribution of aluminum and molybdenum atoms between alpha(p) and 13 matrix. On this basis, the sizes of alpha(p) were theoretically calculated after continuous cooling based on a diffusion-controlled model, and model predictions showed good agreement with experimental measurements. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.; The epitaxial growth behaviors of equiaxed primary alpha phase (alpha(p)) at different cooling rates (150-0.15 degrees C/s) in a near alpha titanium alloy Ti60 were studied by optical micrograph, back scattered electron (BSE) images, high-resolution electron backscatter diffraction technique (EBSD) and electron probe micro-analysis (EPMA). Microstructural observations indicated that the size of alpha(p) significantly increased with decreasing cooling rate. The rim-alpha phase observed by BSE image, which formed at the periphery of ap during cooling and has an identical crystallographic orientation to the interior region of alpha(p) analyzed by Kikuchi diffraction patterns, is considered to be evidence of epitaxial growth of alpha(p). EBSD analysis also showed that ap preferentially grew extending for a distance along the WO boundary resulting in extension-alpha phase from alpha(p). The EPMA confirmed that contrast difference in BSE image within alpha(p) is caused by the difference in composition. The further microanalysis of local composition indicated that epitaxial growth during continuous cooling is mainly controlled by the diffusional redistribution of aluminum and molybdenum atoms between alpha(p) and 13 matrix. On this basis, the sizes of alpha(p) were theoretically calculated after continuous cooling based on a diffusion-controlled model, and model predictions showed good agreement with experimental measurements. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[gao, xiongxiong ; zeng, weidong ; zhang, saifei] northwestern polytech univ, state key lab solidificat proc, xian 710072, peoples r china ; [wang, qingjiang] chinese acad sci, inst met res, shenyang 110016, peoples r china
关键词	Titanium Alloy Microstructure Epitaxial Growth Rim-alpha Solute Atoms Diffusion
学科领域	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	Research Fund for the Program of National Natural Science Foundation of China [51075333]; Program of National Key Research and Development Plan of China [2016YFB0301200]
收录类别	SCI
语种	英语
WOS记录号	WOS:000389556300028
引用统计	被引频次：97[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/321006/78384
专题	中国科学院金属研究所
通讯作者	Zeng, WD (reprint author), Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China.
推荐引用方式 GB/T 7714	Gao, Xiongxiong,Zeng, Weidong,Zhang, Saifei,et al. A study of epitaxial growth behaviors of equiaxed alpha phase at different cooling rates in near alpha titanium alloy[J]. ACTA MATERIALIA,2017,122:298-309.
APA	Gao, Xiongxiong,Zeng, Weidong,Zhang, Saifei,Wang, Qingjiang,&Zeng, WD .(2017).A study of epitaxial growth behaviors of equiaxed alpha phase at different cooling rates in near alpha titanium alloy.ACTA MATERIALIA,122,298-309.
MLA	Gao, Xiongxiong,et al."A study of epitaxial growth behaviors of equiaxed alpha phase at different cooling rates in near alpha titanium alloy".ACTA MATERIALIA 122(2017):298-309.