Hits:

Indexed by:期刊论文

Date of Publication:2009-10-01

Journal:JOURNAL OF SOLID STATE CHEMISTRY

Included Journals:SCIE、EI、Scopus

Volume:182

Issue:10

Page Number:2664-2669

ISSN No.:0022-4596

Key Words:Nickel aluminides; Mechanical properties; Electrical properties; First-principle electron theory; Heats of formation; Multi-materials systems

Abstract:The structural properties, heats of formation, elastic properties, and electronic structures of Al-Ni intermetallic compounds are analyzed here in detail by using density functional theory. Higher calculated absolute values of heats of formation indicate a very strong chemical interaction between Al and Ni for all Al-Ni intermetallic compounds. According to the computational single crystal elastic constants, all the Al-Ni intermetallic compounds considered here are mechanically stable. The polycrystalline elastic modulus and Poisson's ratio have been deduced by using Voigt, Reuss, and Hill (VRH) approximations, and the calculated ratio of shear modulus to bulk modulus indicated that AlNi, Al(3)Ni, AlNi(3) and Al(3)Ni(5) compounds are ductile materials, but Al(4)Ni(3) and Al(3)Ni(2) are brittle materials. With increasing Ni concentration, the bulk modulus of Al-Ni intermetallic compounds increases in a linear manner. The electronic energy band structures confirm that all Al-Ni intermetallic compounds are conductors. (C) 2009 Elsevier Inc. All rights reserved.