| Characteristics, Mechanism and Criterion of Channel Segregation in NbTi Alloy via Numerical Simulations and Experimental Characterizations | |
| Zhu, Baohui1; Chen, Zhenzhen2,3; Cao, Yanfei2; Liu, Yanchang1; Kang, Xiuhong2; Chen, Yun2; Liu, Hongwei2; Fu, Paixian2; Luan, Yikun2; Li, Dianzhong2 | |
| Corresponding Author | Cao, Yanfei(yfcao10s@imr.ac.cn) ; Li, Dianzhong(dzli@imr.ac.cn) |
| 2021-02-01 | |
| Source Publication | MATERIALS
 |
| Volume | 14Issue:4Pages:17 |
| Abstract | Channel segregation (CS) is the most typical defect during solidification of NbTi alloy. Based on numerical simulation and experimental characterizations, we deeply elucidated its characteristics, formation mechanism, effecting factor and prediction criterion. According to acid etching, industrial X-ray transmission imaging, 3D X-ray microtomography and chemical analysis, it was found that in a casing ingot, by He cooling, finer grain size, weaker segregation and slighter CS can be obtained compared with air-cooled ingot. The simulation results of macrosegregation show that CS is caused by the strong natural convection in the mushy zone triggered by the thermo-solutal gradient. Its formation can be divided into two stages including channel initiation and growth. In addition, due to the stronger cooling effect of the He treatment, the interdendritic flow velocity becomes smaller, consequently lowering the positive segregation and CS and improving the global homogenization of the final ingot. Finally, to predict the formation of CS, the Rayleigh number model was proposed and its critical value was found to be 15 in NbTi alloy for the first time. When it is lower than the threshold, CS disappears. It provides an effective tool to evaluate and optimize the solidification parameters to fabricate the homogenized NbTi ingot in engineering practice. |
| Keyword | NbTi alloy channel segregation simulations experimental characterizations criterion |
| Funding Organization | National Natural Science Foundation of China ; State Key Laboratory of Special Rare Metal Materials in Northwest Rare Metal Materials Research Institute Ningxia Co., Ltd. ; CAS Light of West China ; Key Project of Ningxia Hui Autonomous Region Key Research and Development Program ; National Science and Technology Major Project ; Project to Strengthen Industrial Development at the Grass-roots Level ; Young Talent Project by SYNL |
| DOI | 10.3390/ma14040796 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Natural Science Foundation of China[51701225] ; National Natural Science Foundation of China[U1708252] ; State Key Laboratory of Special Rare Metal Materials in Northwest Rare Metal Materials Research Institute Ningxia Co., Ltd.[SKL2017K002] ; CAS Light of West China[XAB2017AW10] ; Key Project of Ningxia Hui Autonomous Region Key Research and Development Program[2018BDE02022] ; National Science and Technology Major Project[2017-VII-0008-0101] ; Project to Strengthen Industrial Development at the Grass-roots Level[TC190A4DA/35] ; Young Talent Project by SYNL[L2019F33] |
| WOS Research Area | Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering ; Physics |
| WOS Subject | Chemistry, Physical ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering ; Physics, Applied ; Physics, Condensed Matter |
| WOS ID | WOS:000624089800001 |
| Publisher | MDPI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/160513 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Cao, Yanfei; Li, Dianzhong |
| Affiliation | 1.Northwest Rare Met Mat Res Inst Ningxia Co Ltd, State Key Lab Special Rare Met Mat, Shizuishan 753000, Peoples R China 2.Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang 110016, Peoples R China 3.Univ Sci & Technol China, Sch Mat Sci & Engn, Hefei 230026, Peoples R China |
| Recommended Citation GB/T 7714 | Zhu, Baohui,Chen, Zhenzhen,Cao, Yanfei,et al. Characteristics, Mechanism and Criterion of Channel Segregation in NbTi Alloy via Numerical Simulations and Experimental Characterizations[J]. MATERIALS,2021,14(4):17. |
| APA | Zhu, Baohui.,Chen, Zhenzhen.,Cao, Yanfei.,Liu, Yanchang.,Kang, Xiuhong.,...&Li, Dianzhong.(2021).Characteristics, Mechanism and Criterion of Channel Segregation in NbTi Alloy via Numerical Simulations and Experimental Characterizations.MATERIALS,14(4),17. |
| MLA | Zhu, Baohui,et al."Characteristics, Mechanism and Criterion of Channel Segregation in NbTi Alloy via Numerical Simulations and Experimental Characterizations".MATERIALS 14.4(2021):17. |
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