TEM study on lamellar microstructure and alpha(2)/gamma interfacial structure in a hot-deformed two-phase gamma-TiAl-based alloy

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	TEM study on lamellar microstructure and alpha(2)/gamma interfacial structure in a hot-deformed two-phase gamma-TiAl-based alloy
	L. C. Zhang; G. L. Chen; J. G. Wang; H. Q. Ye
	1998
发表期刊	Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
ISSN	0921-5093
卷号	247 期号:1-2 页码:40915
摘要	The hot deformation behavior of the lamellar microstructure in a Ti-45Al-8Nb-2.5Mn-0.05B alloy has been studied by transmission electron microscopy (TEM). Numerous subgrain boundaries and two types of deformation twins were frequently observed in the hot-deformation-induced lamellae. The occurrence of nonequilibrium semi-coherent alpha(2)/gamma interfaces is an important microstructural feature of hot-deformed lamellar microstructure in a similar Ti-45Al-10Nb-2.5Mn-0.05B alloy. The distinctiveness of these alpha(2)/gamma interfaces is the misorientation from the conventional alpha(2)/gamma orientation relationship{111}(y) parallel to {0001}(alpha 2), <1 (1) over bar 0<(gamma) parallel to <11 (2) over bar 0>(alpha 2), as well as the asymmetry in the sense of interfacial boundary planes deviating from the equilibrium atomic planes (111)(gamma) or (0001)(alpha 2). Numerous interfacial ledges containing 1/3[111] Frank partial dislocations exist in this nonequilibrium semi-coherent alpha(2)/gamma interface. The analyses point out that, in the hot-deformation-induced bent lamellae, the 1/3[111] Frank partial dislocations in the ledges of alpha(2)/gamma interfaces can be formed by reactions between the matrix and interfacial dislocations. This type of semi-coherent alpha(2)/gamma interface is formed in order to accommodate the relative rotation of alpha(2) and gamma plates resulting from their heterogeneous deformation behavior. In the sharply bent lamellae, there even occur largely misoriented, non-coherent alpha(2)/gamma interfaces with the {111}(gamma) plane no longer being parallel to the {0001}(alpha 2) plane, resulting from the lamellae bending/kinking during heavy deformation. At these nonequilibrium, non-coherent alpha(2)/gamma interfaces with high interfacial strain energy, the T(Q) deformation twins, being inclined to the lamellar interface, are observed to be preferentially formed. The process is favored by the localized stress field of the interfacial misfit dislocations. (C) 1998 Elsevier Science S.A. All rights reserved.
部门归属	univ sci & technol beijing, state key lab adv met & mat, beijing 100083, peoples r china. acad sinica, inst met res, atom imaging solids lab, shenyang 110015, peoples r china.;zhang, lc (reprint author), univ sci & technol beijing, state key lab adv met & mat, beijing 100083, peoples r china
关键词	Tial Alloy Deformation Lamellae Bending/kinking Alpha(2)/gamma Interface Hrem Microstructure Transmission Electron-microscopy Titanium Aluminide Dislocation-structure Deformation Boundaries
URL	查看原文
WOS记录号	WOS:000074723700001
引用统计	被引频次：22[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/321006/37872
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	L. C. Zhang,G. L. Chen,J. G. Wang,et al. TEM study on lamellar microstructure and alpha(2)/gamma interfacial structure in a hot-deformed two-phase gamma-TiAl-based alloy[J]. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,1998,247(1-2):40915.
APA	L. C. Zhang,G. L. Chen,J. G. Wang,&H. Q. Ye.(1998).TEM study on lamellar microstructure and alpha(2)/gamma interfacial structure in a hot-deformed two-phase gamma-TiAl-based alloy.Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,247(1-2),40915.
MLA	L. C. Zhang,et al."TEM study on lamellar microstructure and alpha(2)/gamma interfacial structure in a hot-deformed two-phase gamma-TiAl-based alloy".Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing 247.1-2(1998):40915.