Microstructure evolution and mechanical properties of a Ti-45Al-8.5Nb-(W, B, Y) alloy obtained by controlled cooling from a single β region

被引：27
作者：
Cao, Bei [1 ]
Yang, Jieren [1 ]
Wang, Xuyang [1 ]
Wu, Yulun [1 ]
Hu, Rui [1 ]
机构：
[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian, Shaanxi, Peoples R China
来源：
JOURNAL OF ALLOYS AND COMPOUNDS | 2018年 / 740卷
基金：
中国国家自然科学基金;
关键词：
TiAl alloy; Microstructure; Phase transitions; Transmission electron microscopy; TEM; Mechanical properties; TIAL-BASED ALLOYS; FULLY LAMELLAR MICROSTRUCTURES; PHASE-TRANSFORMATION; HEAT-TREATMENT; HIGH NB; GRAIN-REFINEMENT; IN-SITU; BEHAVIOR; ALPHA; CAST;
D O I：
10.1016/j.jallcom.2017.12.326
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
An accurate temperature-controlled approach was developed to investigate the microstructure evolution of a high-Nb-containing TiAl alloy. The Ti-45Al-8.5Nb-(W, B, Y) alloy was subjected to controlled heating and cooling from the single beta phase region (1500 degrees C) under various processing parameters. Three typical microstructures involving full lamellar (FL), near lamellar (NL) and quenched martensite plates exist in the cooled microstructures. The initial microstructural homogeneity obtained by isothermal holding within the beta phase region can effectively reduce the microsegregation in the subsequent cooling process. The fraction of alpha(2) phase and the lamellar spacing significantly decrease with an increased cooling rate. Furthermore, the crystalline orientations between coarsened block gamma, retained beta/B2 and alpha(2) martensite were identified, and the phase transition mechanism was analysed. Lastly, the microhardness of these treated samples was tested, and the microstructure-dependent mechanical properties were evaluated and discussed. (C) 2017 Elsevier B.V. All rights reserved.
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页码：1140 / 1148
页数：9
相关论文
共 41 条
[1]  
Appel F, 2000, ADV ENG MATER, V2, P699, DOI 10.1002/1527-2648(200011)2:11<699::AID-ADEM699>3.0.CO
[2]  
2-J
[3]   Designed fully lamellar microstructures in a γ-TiAl based alloy:: adjustment and micro, structural changes upon long-term isothermal exposure at 700 and 800°C [J].
Beschliesser, M ;
Chatterjee, A ;
Lorich, A ;
Knabl, W ;
Kestler, H ;
Dehm, G ;
Clemens, H .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2002, 329 :124-129
[4]  
Blackburn M, 1970, SCI TECHNOLOGY APPL, P43
[5]   The Effect of Pressure Stress on the Evolution of B2(ω) Phase in High Nb Containing TiAl Alloy [J].
Cao, Bei ;
Yang, Jieren ;
Wang, Xuyang ;
Hu, Rui .
ADVANCED ENGINEERING MATERIALS, 2017, 19 (06)
[6]   Micro segregation in high Nb containing TiAl alloy ingots beyond laboratory scale [J].
Chen, G. L. ;
Xu, X. J. ;
Teng, Z. K. ;
Wang, Y. L. ;
Lin, J. P. .
INTERMETALLICS, 2007, 15 (5-6) :625-631
[7]   OXIDATION AND MECHANICAL-BEHAVIOR OF INTERMETALLIC ALLOYS IN THE TI-NB-AL TERNARY-SYSTEM [J].
CHEN, GL ;
SUN, ZQ ;
XING, Z .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 1992, 153 (1-2) :597-601
[8]  
Chen GL, 1999, GAMMA TITANIUM ALUMINIDES 1999, P371
[9]   The decomposition of the beta phase in Ti-44Al-8Nb and Ti-44Al-4Nb-4Zr-0.2Si alloys [J].
Cheng, TT ;
Loretto, MH .
ACTA MATERIALIA, 1998, 46 (13) :4801-4819
[10]   Design, Processing, Microstructure, Properties, and Applications of Advanced Intermetallic TiAl Alloys [J].
Clemens, Helmut ;
Mayer, Svea .
ADVANCED ENGINEERING MATERIALS, 2013, 15 (04) :191-215
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