Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels through nanoscale Cu partitioning

doi:10.1016/j.actamat.2020.116561

IMR OpenIR

	Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels through nanoscale Cu partitioning
	Zhou, B. C.1; Yang, T.2; Zhou, G.3; Wang, H.3; Luan, J. H.2; Jiao, Z. B.1,4
通讯作者	Jiao, Z. B.(zb.jiao@polyu.edu.hk)
	2021-02-15
发表期刊	ACTA MATERIALIA
ISSN	1359-6454
卷号	205 页码:11
摘要	Control of discontinuous and continuous precipitation is crucial for tailoring the microstructure and mechanical properties of NiAl-strengthened steels. Through a combination of atom probe tomography, transmission electron microscopy, electron backscatter diffraction, first-principles calculations, and mechanical tests, we demonstrate that Cu is effective in not only promoting the nano-scale continuous NiAl precipitation but also in suppressing the coarse-scale discontinuous NiAl precipitation at grain boundaries, which results in the development of new NiAl-strengthened steels with a high yield strength (1400 MPa) and good ductility (10%). Our analyses indicate that the mechanisms for suppressing discontinuous NiAl precipitation are twofold. The main one is the acceleration of continuous NiAl precipitation through Cu partitioning, which swiftly reduces the matrix supersaturation, thereby decreasing the chemical driving force for the growth of discontinuous precipitates. The other is the reduction of grain boundary energy through Cu segregation, which is likely to decrease the nucleation rate of discontinuous precipitates. Consequently, Cu increases the number density of continuous NiAl nanoparticles by more than fivefold, which leads to a twofold enhancement in the strengthening and an improvement in the over-aging resistance of NiAl-strengthened steels. The effects of Cu on the precipitation strengthening mechanisms were quantitatively evaluated. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词	low-carbon steel discontinuous precipitation precipitate precipitation hardening microstructure formation mechanism
资助者	Research Grants Council of Hong Kong ; National Natural Science Foundation of China ; USTB-State Key Laboratory for Advanced Metals and Materials open fund ; Guangzhou International Science & Technology Cooperation Program ; PolyU-Chinese National Engineering Research Center for Steel Construction under ITF fund
DOI	10.1016/j.actamat.2020.116561
收录类别	SCI
语种	英语
资助项目	Research Grants Council of Hong Kong[25202719] ; National Natural Science Foundation of China[51801169] ; USTB-State Key Laboratory for Advanced Metals and Materials open fund[2017-ZD01] ; Guangzhou International Science & Technology Cooperation Program[201907010026] ; PolyU-Chinese National Engineering Research Center for Steel Construction under ITF fund[P0013862]
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000609936600031
出版者	PERGAMON-ELSEVIER SCIENCE LTD
引用统计	被引频次：66[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/321006/159097
专题	中国科学院金属研究所
通讯作者	Jiao, Z. B.
作者单位	1.Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Peoples R China 2.City Univ Hong Kong, Dept Mat Sci & Engn, Hong Kong, Peoples R China 3.Chinese Acad Sci, Shi Changxu Innovat Ctr Adv Mat, Inst Met Res, Shenyang 110016, Peoples R China 4.Hong Kong Polytech Univ, Shenzhen Res Inst, Shenzhen 518057, Peoples R China
推荐引用方式 GB/T 7714	Zhou, B. C.,Yang, T.,Zhou, G.,et al. Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels through nanoscale Cu partitioning[J]. ACTA MATERIALIA,2021,205:11.
APA	Zhou, B. C.,Yang, T.,Zhou, G.,Wang, H.,Luan, J. H.,&Jiao, Z. B..(2021).Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels through nanoscale Cu partitioning.ACTA MATERIALIA,205,11.
MLA	Zhou, B. C.,et al."Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels through nanoscale Cu partitioning".ACTA MATERIALIA 205(2021):11.