Modeling of the site preference in ternary B2-ordered Ni–Al–Fe alloys

Journal of Alloys and Compounds

Noebe

Mosca

2005

Self Cite

Atomistic modeling of the site substitution behavior of Pd in NiTi (J. Alloys and Comp. (2004), in press) has been extended to examine the behavior of several other alloying additions, namely, Fe, Pt, Au, Al, Cu, Z r and Hf in this important shape memory alloy. It was found that all elements, to a varying degree, displayed absolute preference for available sites in the deficient sublattice. However, the energetics of the different substitutional schemes, coupled with large scale simulations indicate that the general trend in all cases is for the ternary addition to want to form stronger ordered structures with Ti.

Section: Application Of the Bfs Methods To The Study Of Niti+x Alloysmentioning

confidence: 99%

Section: Application Of the Bfs Methods To The Study Of Niti+x Alloysmentioning

confidence: 99%

Site preference of ternary alloying additions to NiTi: Fe, Pt, Pd, Au, Al, Cu, Zr and Hf

Journal of Alloys and Compounds

Noebe

Mosca

2005

Self Cite

“…19, which is a modified version of the traditional Monte CarloMetropolis algorithm. An initial, random, structure is generated by assigning Ni and Pd atoms to rigid (i.e., no individual relaxations) lattice sites in the computational cell with periodic boundary conditions in two directions for surfaces (three directions for bulk cells).…”

Section: The Bfs Methodsmentioning

confidence: 99%

Analysis of surface and bulk behavior in Ni–Pd alloys

Noebe

2003

Acta Materialia

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-The most salient features of the surface structure and bulk behavior of Ni-Pd alloys have been studied using the BFS method for alloys. Large-scale atomistic simulations were performed to investigate surface segregation profiles as a function of temperature, crystal face, and composition. Pd enrichment of the first layer was observed in (111) and (100) surfaces, and enrichment of the top two layers occurred for (1 10) surfaces. In all cases, the segregation profile shows alternate planes enriched and depleted in Pd. In addition, the phase structure of bulk Ni-Pd alloys as a function of temperature and composition was studied. A weak ordering tendency was observed at low temperatures, which helps explain the compositional oscillations in the segregation profiles. Finally, based on atom-by-atom static energy calculations, a comprehensive explanation for the observed surface and bulk features will be presented in terms of competing chemical and strain energy effects.

“…While BFS-based simulations using the BANN algorithm [35] show the formation of the B2 RuAl phase, as can be seen in Fig. 4(a), the results are just as clear for Ni 25 Ru 25 Al 50 , as shown in Fig.…”

Section: Modeling Of Rual-based Multicomponent Alloysmentioning

confidence: 86%

Atomistic Modeling of Multicomponent Systems

Garcés²

2007

J Phs Eqil and Diff

The need to accelerate materials design programs based on economical and efficient modeling techniques provides the framework for the introduction of approximations in otherwise rigorous theoretical schemes. Several quantum approximate methods have been introduced through the years, bringing new opportunities for the efficient understanding of complex multicomponent alloys at the atomic level. As a promising example of the role that these methods might have in the development of complex systems, in this work we discuss the Bozzolo-Ferrante-Smith (BFS) method for alloys and its application to a variety of multicomponent systems for a detailed analysis of their defect and phase structure and their properties. Examples include the study of the phase structure of new Ru-rich Ni-base superalloys, the role of multiple alloying additions in high temperature intermetallic alloys, and interfacial phenomena in nuclear materials, highlighting the benefits that can be obtained from introducing simple modeling techniques to the investigation of complex systems.