Atomic-scale observations of B2 → ω-related phases transition in high-Nb containing TiAl alloy

被引：19

作者：

Wang, Xuyang ^{[1
]}

Yang, Jieren ^{[1
]}

Zhang, Keren ^{[1
]}

Hu, Rui ^{[1
]}

Song, Lin ^{[1
]}

Fu, Hengzhi ^{[1
]}

机构：

[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Shaanxi, Peoples R China

来源：

MATERIALS CHARACTERIZATION | 2017年 / 130卷

基金：

中国国家自然科学基金;

关键词：

TiAl alloy; Transmission electron microscopy (TEM); Diffusion; Phase transformation; Omega phase; MECHANICAL-PROPERTIES; BETA; MICROSTRUCTURE; CAST; TI-45AL-8.5NB-(W; TRANSFORMATIONS; EVOLUTION; AL;

D O I：

10.1016/j.matchar.2017.06.003

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The nucleation of omega-related phases within B2-phase region in Ti-45A1-8.5Nb-(W, B, Y) (at.%) alloy were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). At 850 degrees C, the metastable B2 phase decomposes to omega particles quickly. Experimental evidence from high-resolution images revealed that first the atoms redistribute in the B2 structure, and then the original (111)(B2) planes collapse during B2 -> omega", which represents a "diffusion-collapse" pathway. The further collapse of (0001)(omega) planes in [0001](omega) zone, that is omega" -> omega(o), is a sequential and uneven process rather than an instantaneous transition, which may be attributed to that an uneven structure transition could decrease the energy barrier.

引用

页码：135 / 138

页数：4

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