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

Xuyang Wang; Jieren Yang; Keren Zhang; Rui Hu; Lin Song; Hengzhi Fu

doi:10.1016/j.matchar.2017.06.003

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

Xuyang Wang, Jieren Yang, Keren Zhang, Rui Hu, Lin Song, Hengzhi Fu

School of Materials Sience and Engineering

Northwestern Polytechnical University Xian

Research output: Contribution to journal › Article › peer-review

18 Scopus citations

Abstract

The nucleation of ω-related phases within B2-phase region in Ti-45Al-8.5Nb-(W, B, Y) (at.%) alloy were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). At 850 °C, the metastable B2 phase decomposes to ω particles quickly. Experimental evidence from high-resolution images revealed that first the atoms redistribute in the B2 structure, and then the original 11¯1_B2 planes collapse during B2 → ω″, which represents a “diffusion-collapse” pathway. The further collapse of (0001)_ω planes in [0001]_ω zone, that is ω″ → ω_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.

Original language	English
Pages (from-to)	135-138
Number of pages	4
Journal	Materials Characterization
Volume	130
DOIs	https://doi.org/10.1016/j.matchar.2017.06.003
State	Published - Aug 2017

Keywords

Diffusion
Omega phase
Phase transformation
TiAl alloy
Transmission electron microscopy (TEM)

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10.1016/j.matchar.2017.06.003

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

abstract = "The nucleation of ω-related phases within B2-phase region in Ti-45Al-8.5Nb-(W, B, Y) (at.%) alloy were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). At 850 °C, the metastable B2 phase decomposes to ω particles quickly. Experimental evidence from high-resolution images revealed that first the atoms redistribute in the B2 structure, and then the original 11¯1B2 planes collapse during B2 → ω″, which represents a “diffusion-collapse” pathway. The further collapse of (0001)ω planes in [0001]ω zone, that is ω″ → ωo, 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.",

keywords = "Diffusion, Omega phase, Phase transformation, TiAl alloy, Transmission electron microscopy (TEM)",

author = "Xuyang Wang and Jieren Yang and Keren Zhang and Rui Hu and Lin Song and Hengzhi Fu",

note = "Publisher Copyright: {\textcopyright} 2017 Elsevier Inc.",

year = "2017",

month = aug,

doi = "10.1016/j.matchar.2017.06.003",

language = "英语",

volume = "130",

pages = "135--138",

journal = "Materials Characterization",

issn = "1044-5803",

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T1 - Atomic-scale observations of B2 → ω-related phases transition in high-Nb containing TiAl alloy

AU - Wang, Xuyang

AU - Yang, Jieren

AU - Zhang, Keren

AU - Hu, Rui

AU - Song, Lin

AU - Fu, Hengzhi

PY - 2017/8

Y1 - 2017/8

N2 - The nucleation of ω-related phases within B2-phase region in Ti-45Al-8.5Nb-(W, B, Y) (at.%) alloy were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). At 850 °C, the metastable B2 phase decomposes to ω particles quickly. Experimental evidence from high-resolution images revealed that first the atoms redistribute in the B2 structure, and then the original 11¯1B2 planes collapse during B2 → ω″, which represents a “diffusion-collapse” pathway. The further collapse of (0001)ω planes in [0001]ω zone, that is ω″ → ωo, 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.

AB - The nucleation of ω-related phases within B2-phase region in Ti-45Al-8.5Nb-(W, B, Y) (at.%) alloy were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). At 850 °C, the metastable B2 phase decomposes to ω particles quickly. Experimental evidence from high-resolution images revealed that first the atoms redistribute in the B2 structure, and then the original 11¯1B2 planes collapse during B2 → ω″, which represents a “diffusion-collapse” pathway. The further collapse of (0001)ω planes in [0001]ω zone, that is ω″ → ωo, 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.

KW - Diffusion

KW - Omega phase

KW - Phase transformation

KW - TiAl alloy

KW - Transmission electron microscopy (TEM)

UR - http://www.scopus.com/inward/record.url?scp=85020287265&partnerID=8YFLogxK

U2 - 10.1016/j.matchar.2017.06.003

DO - 10.1016/j.matchar.2017.06.003

M3 - 文章

AN - SCOPUS:85020287265

SN - 1044-5803

VL - 130

SP - 135

EP - 138

JO - Materials Characterization

JF - Materials Characterization

ER -

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

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Keywords

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