Effect of purity on solidification structure and micro-segregation in a nickel-based single crystal superalloy

doi:10.1016/j.jallcom.2024.174929

IMR OpenIR

	Effect of purity on solidification structure and micro-segregation in a nickel-based single crystal superalloy
	Wang, Yinghao 1; Zhang, Xiaoxin 1; Tian, Haoxin 1; Hao, Long 1; Tian, Zhirui 1; Meng, Jie 2; Birich, Alexander 3; Tan, Yi 4; Xuan, Weidong 1; Ren, Zhongming 1
通讯作者	Zhang, Xiaoxin(zhangxiaoxin@shu.edu.cn)
	2024-09-15
发表期刊	JOURNAL OF ALLOYS AND COMPOUNDS
ISSN	0925-8388
卷号	999 页码:11
摘要	The purity of nickel-based single crystal alloys plays an important role in the final service performance of turbine blades as it impacts the solidification structure, elemental segregation, and inclusions of castings. The highest purity of superalloys studied before was of altogether around 10 ppm of contents of N and O produced by the triple purification process (VIM+ESR+VAR). However, the impact mechanism still remains controversial, and meanwhile whether a lower content of N and O still keeps the impacts on castings is not yet clear due to the lack of raw materials. A superhigh purity of second generation of nickel-based single crystal superalloy DD98M with the sum of N and O contents as low as 4 ppm (hitherto the highest purity of the superalloy as published), homeproduced by electron beam smelting (EBS), was put on focus in this work. The effect of three levels of purity (Ndoped, commercial, and EBS, corresponding to 21, 10, and 4 ppm for the sum of N and O contents, respectively) on the microstructure evolution (including primary dendrite arm spacing (PDAS), eutectic, micropores, and gamma ' phase) and the solute segregation behavior at dendritic scale and nano scale (gamma/gamma ' interfaces) were systematically studied and the influencing mechanisms were elucidated. The results show that the PDAS decreased from 406 mu m to 322 mu m with the reduction of O and N from 21 ppm to 4 ppm, which was irrelevant to precipitation of the nitride or oxide inclusions. Instead, it was due to the decrease of diffusion coefficient D or the increase of equilibrium coefficient k, or the decrease of the critical nucleation supercooling and the incubation time of dendrites. The micro-segregation, the number and volume fraction of eutectic, and the number and voltage percentage of shrinkage pores and gas pores were all greatly decreased with the increase of purity. These changes were closely related to the reduction of PDAS and the reduction of fluidity of the remained liquid in the interdendrites during solidification. The morphology and the size of the gamma ' phase were independent from the purity, while the segregation of alloying elements at the gamma/gamma ' interface changed remarkably with the variation of the purity.
关键词	Nickle-based single crystal superalloy DD98M High purity Solidification structure Micro-segregation
资助者	National Key Research and Devel- opment Program of China ; Shanghai Yangfan Program of Science and Technology Commission ; National Natural Science Foundation of China ; Shanghai Technology Innovation Project
DOI	10.1016/j.jallcom.2024.174929
收录类别	SCI
语种	英语
资助项目	National Key Research and Devel- opment Program of China[2019YFA0705300] ; Shanghai Yangfan Program of Science and Technology Commission[21YF1413000] ; National Natural Science Foundation of China[52127807] ; Shanghai Technology Innovation Project[XTCX-KJ-2023-2-20]
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:001249082400002
出版者	ELSEVIER SCIENCE SA
引用统计
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/187364
专题	中国科学院金属研究所
通讯作者	Zhang, Xiaoxin
作者单位	1.Shanghai Univ, Sch Mat Sci & Engn, State Key Lab Adv Special Steels, Shanghai 200444, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shi changxu Innovat Ctr Adv Mat, Shenyang 110016, Peoples R China 3.Rhein Westfal TH Aachen, Inst Proc Met & Met Recycling, D-52056 Aachen, Germany 4.Dalian Univ Technol, Sch Mat Sci & Engn, Dalian 116023, Peoples R China
推荐引用方式 GB/T 7714	Wang, Yinghao,Zhang, Xiaoxin,Tian, Haoxin,et al. Effect of purity on solidification structure and micro-segregation in a nickel-based single crystal superalloy[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2024,999:11.
APA	Wang, Yinghao.,Zhang, Xiaoxin.,Tian, Haoxin.,Hao, Long.,Tian, Zhirui.,...&Ren, Zhongming.(2024).Effect of purity on solidification structure and micro-segregation in a nickel-based single crystal superalloy.JOURNAL OF ALLOYS AND COMPOUNDS,999,11.
MLA	Wang, Yinghao,et al."Effect of purity on solidification structure and micro-segregation in a nickel-based single crystal superalloy".JOURNAL OF ALLOYS AND COMPOUNDS 999(2024):11.