Recalescence behaviour of binary Ti-Al and ternary Ti-Al-Nb undercooled melts

被引：14

作者：

Löser, W ^{[1
]}

Lindenkreuz, HG ^{[1
]}

Hermann, R ^{[1
]}

Shuleshova, O ^{[1
]}

Woodcock, TG ^{[1
]}

机构：

[1] Leibniz Inst Festkorper & Werkstofforsch IFW Dres, D-01171 Dresden, Germany

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2005年 / 413卷

关键词：

intermetallics; alloy solidification; titanium alloys; melt undercooling;

D O I：

10.1016/j.msea.2005.09.005

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The recalescence behaviour of undercooled melts of binary Ti55Al45, Ti50Al50, Ti45Al55, and ternary Ti45Al50Nb5, T45Al45Nb10, Ti40Al50Nb10 alloys have been studied by a containerless electromagnetic levitation technique in a He/H-2 atmosphere in order to reveal phase formation and microstructure evolution processes. The time-temperature traces of the pyrometer exhibit steep single recalescence events for undercooling values of similar to 300 K below the liquidus temperature. Dendrite growth velocities of the order of 10-20 m/s for highly undercooled ternary Ti-Al-Nb melts are consistent with a primarily formed bcc beta-phase, which is promoted by Nb addition. For ternary Ti45Al50Nb5 and Ti40Al50Nb10 alloy compositions, a second recalescence near 1300 degrees C was observed, which can be attributed to a solid state transformation. The microstructure of levitated melt drops subsequently quenched onto a chill substrate shows more evidence for the predicted phase transformations. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：398 / 402

页数：5

共 15 条

[1] SOLIDIFICATION KINETICS AND METASTABLE PHASE FORMATION IN BINARY TI-AL [J].

ANDERSON, CD ;

HOFMEISTER, WH ;

BAYUZICK, RJ .

METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1992, 23 (10) :2699-2714

[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]

Clemens H, 2000, ADV ENG MATER, V2, P551, DOI 10.1002/1527-2648(200009)2:9<551::AID-ADEM551>3.0.CO

[5]

2-U

[6] Phase equilibria in the Al-Nb-Ti system at high temperatures [J].

Hellwig, A ;

Palm, M ;

Inden, G .

INTERMETALLICS, 1998, 6 (02) :79-94

[7] THERMODYNAMIC CALCULATION OF THE TERNARY TI-AL-NB SYSTEM [J].

KATTNER, UR ;

BOETTINGER, WJ .

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 1992, 152 (1-2) :9-17

[8] THERMODYNAMIC ASSESSMENT AND CALCULATION OF THE TI-AL SYSTEM [J].

KATTNER, UR ;

LIN, JC ;

CHANG, YA .

METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1992, 23 (08) :2081-2090

[9] Mechanism for metastable phase formation in undercooled Ti-Al peritectic alloys [J].

Liu, YC ;

Shi, QZ ;

Yang, GC ;

Zhou, YH .

MATERIALS LETTERS, 2004, 58 (3-4) :428-431

[10]

LOSER W, 1994, ANN REPORT I FESTKOR, P27

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