Crystal structure and phase stability of AlSc in the near-equiatomic Al-Sc alloy

被引：4

作者：

Li, Juan ^{[1
]}

Huang, Li ^{[1
]}

Liang, Yongfeng ^{[1
]}

Ye, Feng ^{[1
]}

Lin, Junpin ^{[1
]}

Shang, Shunli ^{[2
]}

Liu, Zikui ^{[2
]}

机构：

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

[2] Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2015年 / 618卷

基金：

国家高技术研究发展计划(863计划);

关键词：

Intermetallics; Crystal structure; Phase transitions; Transmission electron microscopy; SCANDIUM;

D O I：

10.1016/j.jallcom.2014.08.111

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：

Intermetallic compound AlSc is found in the equiatomic Al-Sc binary alloy. The present work indicates that the orthorhombic AlSc with the Au2CuZn-type structure can be formed at 50 at.% Sc, while the CsCI-type (B2) AlSc will be formed at 55 at.% Sc. After annealing at 1100 degrees C, some orthorhombic AlSc grains transit to the B2 structure, and the annealing at lower temperatures leads to the disappearance of B2 phase, indicating that the B2 AlSc is also a metastable phase in the alloy at lower Sc content (<50 at.%). First-principle calculations at 0 K reveal that the orthorhombic AlSc is more stable than the B2 AlSc with the energy difference between them being 5.4 meWatom. The fast transition between these two phases, which cannot be interpreted by the mechanism of atomic diffusion, was tentatively analyzed by the volume change based on the calculated atomic positions of these two phases. (C) 2014 Elsevier B.V. All rights reserved.

引用

页码：192 / 196

页数：5

共 21 条

[1] Structural, vibrational, and thermodynamic properties of Al-Sc alloys and intermetallic compounds [J].

Asta, M ;

Ozolins, V .

PHYSICAL REVIEW B, 2001, 64 (09)

[2] PROJECTOR AUGMENTED-WAVE METHOD [J].

BLOCHL, PE .

PHYSICAL REVIEW B, 1994, 50 (24) :17953-17979

[3] Thermodynamic measurements and assessment of the Al-Sc system [J].

Cacciamani, G ;

Riani, P ;

Borzone, G ;

Parodi, N ;

Saccone, A ;

Ferro, R ;

Pisch, A ;

Schmid-Fetzer, R .

INTERMETALLICS, 1999, 7 (01) :101-108

[4]

Gschneidner K.A., 1989, Bull. Alloy Phase Diagrams, V10, P34, DOI [10.1007/BF02882170, DOI 10.1007/BF02882170]

[5] Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set [J].

Kresse, G ;

Furthmuller, J .

PHYSICAL REVIEW B, 1996, 54 (16) :11169-11186

[6] From ultrasoft pseudopotentials to the projector augmented-wave method [J].

Kresse, G ;

Joubert, D .

PHYSICAL REVIEW B, 1999, 59 (03) :1758-1775

[7] Lattice Structures of AlSc and Their Effect on Interdiffusion [J].

Li, Juan ;

Ye, Feng ;

Huang, Li ;

Liang, Yongfeng .

HIGH PERFORMANCE STRUCTURE MATERIALS, 2013, 747-748 :9-13

[8] HIGH-PRECISION SAMPLING FOR BRILLOUIN-ZONE INTEGRATION IN METALS [J].

METHFESSEL, M ;

PAXTON, AT .

PHYSICAL REVIEW B, 1989, 40 (06) :3616-3621

[9] The Al-Sc (aluminum-scandium) system [J].

Murray, JL .

JOURNAL OF PHASE EQUILIBRIA, 1998, 19 (04) :380-384

[10] Electronic structure, phase stability and elastic moduli of AB transition metal aluminides [J].

Nguyen-Manh, D ;

Pettifor, DG .

INTERMETALLICS, 1999, 7 (10) :1095-1106

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