Phase transformation and deformation behavior of a TiAl-Nb composite under quasi-static and dynamic loadings

doi:10.1016/j.msea.2021.142155

IMR OpenIR

	Phase transformation and deformation behavior of a TiAl-Nb composite under quasi-static and dynamic loadings
	Wang, Li 1; Liang, Xiaopeng 1,2; Jiang, Fuqing 3; Ouyang, Sihui 1; Liu, Bin 1; Liu, Yong 1
通讯作者	Liu, Yong(yonliu@csu.edu.cn)
	2022
发表期刊	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN	0921-5093
卷号	829 页码:12
摘要	To improve the high-temperature deformability of TiAl intermetallics, a TiAl-Nb intermetallic matrix composite was prepared by powder metallurgy to try to introduce the deformable beta phase. The microstructure and deformation behavior of the TiAl-Nb intermetallic matrix composite under quasi-static and dynamic conditions were systematically investigated. It is found that the microstructure of the composite is composed of a near gamma TiAl matrix and Nb-rich regions. In the Nb-rich regions a coexistence of beta(o), omega(o) and gamma phases was identified where omega(o) and gamma phases were supposed to directly precipitate in the beta(o) matrix. The ultimate tensile strength of the composite exhibits different temperature-dependent behaviors under quasi-static and dynamic loading conditions. It increases with temperatures up to 650 degrees C and then declines with temperature under quasi-static loading, while it does not decrease from 650 to 850 degrees C under the dynamic loading. In the deformed microstructures, the Nb-rich regions at all conditions are still composed of beta(o), omega(o) and gamma phases, indicating that the solvus temperature of the omega(o) phase could be above 850 degrees C. Additionally, the TiAl matrix appears to not significantly contribute to the plastic deformation of the composite, where the propensity of dislocations and mechanical twins do not significantly change when varying loading conditions. However, the gamma particles formed in Nb-rich regions contain substantial mechanical twins and dislocations under both quasi-static and dynamic loading conditions. Thus, the gamma particles directly transformed from the beta(o) phase exhibit better deformability than the gamma phase in the matrix. This could be probably explained by a decreased stacking fault energy for the newly formed gamma phase due to a decrease in Al fraction and a significant increase in Nb fraction. Meanwhile, twin intersections occurred in the gamma particles, and the induced stress concentration in the intersection regions was relieved by lattice distortion and detwinning processes. This twin intersection behavior could be beneficial for improving the composite strength without sacrificing much ductility.
关键词	TiAl intermetallics Composite Phase transformation Deformation behavior Transmission electron microscopy (TEM)
DOI	10.1016/j.msea.2021.142155
收录类别	SCI
语种	英语
WOS研究方向	Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000710240000001
出版者	ELSEVIER SCIENCE SA
引用统计	被引频次：13[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/321006/167080
专题	中国科学院金属研究所
通讯作者	Liu, Yong
作者单位	1.Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China 2.Cent South Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Wang, Li,Liang, Xiaopeng,Jiang, Fuqing,et al. Phase transformation and deformation behavior of a TiAl-Nb composite under quasi-static and dynamic loadings[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2022,829:12.
APA	Wang, Li,Liang, Xiaopeng,Jiang, Fuqing,Ouyang, Sihui,Liu, Bin,&Liu, Yong.(2022).Phase transformation and deformation behavior of a TiAl-Nb composite under quasi-static and dynamic loadings.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,829,12.
MLA	Wang, Li,et al."Phase transformation and deformation behavior of a TiAl-Nb composite under quasi-static and dynamic loadings".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 829(2022):12.