Microstructure evolution and phase transformation of the mushy zone in a quenched β-solidifying TiAl alloy

被引：8

作者：

Zhang, Fuqiang ^{[1
]}

Ding, Xianfei ^{[2
]}

Xu, Leming ^{[1
]}

Feng, Xin ^{[2
]}

Nan, Hai ^{[2
]}

He, Jianping ^{[1
]}

Liang, Yongfeng ^{[1
]}

Lin, Junpin ^{[1
]}

机构：

[1] Univ Sci & Technol Beijing, State Key Lab Adv Met & Mat, Beijing 100083, Peoples R China

[2] Beijing Inst Aeronaut Mat, Cast Titanium Alloy R&D Ctr, Beijing 100095, Peoples R China

来源：

JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY | 2024年 / 169卷

基金：

中国国家自然科学基金;

关键词：

Titanium aluminides; Mushy zone; Quenching; Electron backscattering diffraction; Phase transformation; TIAL/TI3AL LAMELLAR MICROSTRUCTURE; TRANSMISSION ELECTRON-MICROSCOPY; THERMAL STABILIZATION TREATMENT; DIRECTIONAL SOLIDIFICATION; VARIANT SELECTION; MASSIVE TRANSFORMATION; BETA-PHASE; NB ALLOYS; GAMMA; ALPHA;

D O I：

10.1016/j.jmst.2023.05.070

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

This study investigates the phase constitutions and transformations that occur in the mushy zone and in the adjacent phase fields of a directionally solidified Ti-44Al-8Nb-1Cr alloy via quenching technique. The results indicate that the mushy zone consists of unmelted & beta; dendrites and interdendritic liquid, whose formation can be attributed to the difference in melting point aroused by local heterogeneity in solutecontent. The & beta; dendrite is composed of numerous subgrains with various orientations. During quenching, the & beta; dendrite transforms into Widmanstatten & alpha; via a precipitation reaction, owing to the decreasing cooling rate caused by heat transfer from the surrounding liquid. Additionally, after quenching, the interdendritic liquid is transformed into & gamma; plates. Within the single & beta; phase field and the lower part of the mushy zone, a massive transformation of & beta; to & gamma; occurs . Conversely, in the & beta;-F & alpha; phase field, both & beta; and & alpha; phases are retained to ambient temperature. During the heating process, the transformation of & alpha; - & beta; gives rise to the formation of & beta; variants, which affects the orientation of & beta; dendrites in the mushy zone. The growth kinematics of the & alpha; - & beta; transformation was elucidated, revealing the preferential growth directions of ( 111 ) and ( 112 ) for & beta; variants. Furthermore, this study presents an illustration of the formation process of the mushy zone and the microstructural evolution during the heating and quenching process. & COPY; 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

引用

页码：28 / 41

页数：14

共 69 条

[1] In situ observation of solidification patterns in diffusive conditions [J].

Akamatsu, Silvere ;

Nguyen-Thi, Henri .

ACTA MATERIALIA, 2016, 108 :325-346

[2]

Appel F, 2000, ADV ENG MATER, V2, P699, DOI 10.1002/1527-2648(200011)2:11<699::AID-ADEM699>3.0.CO

[3]

2-J

[4] Modeling concepts for intermetallic titanium aluminides [J].

Appel, F. ;

Clemens, H. ;

Fischer, F. D. .

PROGRESS IN MATERIALS SCIENCE, 2016, 81 :55-124

[5]

Appel F, 2011, GAMMA TITANIUM ALUMINIDE ALLOYS: SCIENCE AND TECHNOLOGY, P1, DOI 10.1002/9783527636204

[6]

Blackburn MJ., 1970, SCI TECHNOLOGY APPL, P633, DOI [10.1016/B978-0-08-006564-9.50071-3, DOI 10.1016/B978-0-08-006564-9.50071-3]

[7] On the process of transition of the cubic-body-centered modification into the hexagonal-close-packed modification of zirconium [J].

Burgers, WG .

PHYSICA, 1934, 1 :561-586

[8] Importance of the α→β transformation in the variant selection mechanisms of thermomechanically processed titanium alloys [J].

Cayron, C. .

SCRIPTA MATERIALIA, 2008, 59 (05) :570-573

[9] Study of microstructure and solute partitioning in a cast Ti-48Al-2Cr-2Nb alloy by quenching during directional solidification technique [J].

Charpentier, M ;

Daloz, D ;

Hazotte, A ;

Gautier, E ;

Lesoult, G ;

Grange, M .

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 2003, 34A (10) :2139-2148

[10] 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

← 1 2 3 4 5 6 7 →