New insights into omega-embrittlement in high misfit metastable beta-titanium alloys: Mechanically-driven omega-mediated amorphization

doi:10.1016/j.matdes.2021.109724

IMR OpenIR

	New insights into omega-embrittlement in high misfit metastable beta-titanium alloys: Mechanically-driven omega-mediated amorphization
	Chen, Wei 1; Cao, Shuo 2; Zhang, Jinyu 1; Zha, You 1; Hu, Qingmiao 2; Sun, Jun 1
通讯作者	Zhang, Jinyu(jinyuzhang1002@mail.xjtu.edu.cn) ; Hu, Qingmiao(qmhu@imr.ac.cn)
	2021-07-01
发表期刊	MATERIALS & DESIGN
ISSN	0264-1275
卷号	205 页码:18
摘要	omega-embrittlement is ubiquitous in metastable beta-titanium (Ti) alloys, while the fundamental understanding on the damage-fracture mechanism hitherto remains elusive. In this study, we systematically investigate omega-embrittlement of high misfit Ti-10Cr (wt.%) alloys by coupling experiments and first-principles calculation. It is found that brittle cleavage-like fracture prevails in tensile samples, irrespective of the quenching or subsequent aging states. Microscopically, cracks nucleation and propagation proceed along slip bands, inside which omega-lattices are first disordered and then the localized (beta + omega)-amorphous-like structures are developed in the shape of white patches. The underlying mechanism of mechanically-driven localized amorphization is that due to the remarkable covalent character of atomic bonding of x-precipitates caused by composition partitioning of the Cr element, omega-precipitates impart extremely high energy barrier opposed to dislocation gliding and render dislocations pile-up ahead of omega-precipitates, thus leading to their lattice disordering. It is unveiled that the hydrostatic pressure, serving as the driving force for dislocations pile-up, plays a critical role in this unusual cleavage-like fracture of Ti-10Cr alloys caused by mechanically-driven omega-mediated localized amorphization. Accompanied by the transition from the co-operation of deformation twining and ordinary dislocation slip in the quenched Ti10Cr alloys to the exclusive ordinary dislocation slip in the long-time aged Ti-10Cr samples, it is unexpected that the resulting tensile fracture strength monotonically decreases to a stress level of similar to 100 MPa. These findings provide new insights into the damage and fracture behavior of high misfit beta-titanium alloys, such as Ti-Cr alloys. (C) 2021 The Authors. Published by Elsevier Ltd.
关键词	Titanium alloys omega-precipitates Brittleness Slip band Amorphization
资助者	National Natural Science Foundation of China ; National Key Research and Development Program of China ; 111 Project 2.0 of China ; Natural Science Basic Research Plan in Shaanxi Province of China ; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies ; Fok Ying-Tong Education Foundation ; Fundamental Research Funds for the Central Universities
DOI	10.1016/j.matdes.2021.109724
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[51871176] ; National Natural Science Foundation of China[51722104] ; National Natural Science Foundation of China[51621063] ; National Natural Science Foundation of China[91860107] ; National Natural Science Foundation of China[52071315] ; National Natural Science Foundation of China[52001307] ; National Key Research and Development Program of China[2017YFA0700701] ; 111 Project 2.0 of China[PB2018008] ; Natural Science Basic Research Plan in Shaanxi Province of China[2018JM5098] ; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies ; Fok Ying-Tong Education Foundation[161096] ; Fundamental Research Funds for the Central Universities[xtr022019004]
WOS研究方向	Materials Science
WOS类目	Materials Science, Multidisciplinary
WOS记录号	WOS:000663558100006
出版者	ELSEVIER SCI LTD
引用统计	被引频次：7[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/321006/160602
专题	中国科学院金属研究所
通讯作者	Zhang, Jinyu; Hu, Qingmiao
作者单位	1.Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Chen, Wei,Cao, Shuo,Zhang, Jinyu,et al. New insights into omega-embrittlement in high misfit metastable beta-titanium alloys: Mechanically-driven omega-mediated amorphization[J]. MATERIALS & DESIGN,2021,205:18.
APA	Chen, Wei,Cao, Shuo,Zhang, Jinyu,Zha, You,Hu, Qingmiao,&Sun, Jun.(2021).New insights into omega-embrittlement in high misfit metastable beta-titanium alloys: Mechanically-driven omega-mediated amorphization.MATERIALS & DESIGN,205,18.
MLA	Chen, Wei,et al."New insights into omega-embrittlement in high misfit metastable beta-titanium alloys: Mechanically-driven omega-mediated amorphization".MATERIALS & DESIGN 205(2021):18.