12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone

Computational modelling of Zr-Nb alloys by solid solution approach

14 Jul 2011, 13:45
15m
Acro1

Acro1

Oral Presentation Track A - Condensed Matter Physics and Material Science CMPMS2

Speaker

Ms Moyahabo Chuma (Materials Modelling Centre)

Description

We use density functional theory to investigate the structural, elastic properties and energetic stabilities of Zr, Nb and its alloys in the alpha and beta phases, employing pseudopotential plane wave methods within the Pardew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA). The structures were fully optimized in a non-magnetic state, allowing atomic positions, cell volume and shape to change. Lattice parameters for the pure phases gave excellent agreement with the available experimental data. We also found that the phonon dispersions curves display soft-modes for the metastable beta-Zr phase which is lacking on the alpha-Zr and beta-Nb, condition of mechanical stability. The solid solution calculations show that an increase in the Nb contents destabilizes the structures in both the alpha and beta phases. Interestingly, the calculated elastic moduli for Zr-2.3%Nb are in good agreement to the experimental results of Zr-2.5%Nb.

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? Yes
Consider for a student <br> &nbsp; award (Yes / No)? Yes
Level (Hons, MSc, <br> &nbsp; PhD, other)? Hons

Primary authors

Dr Hasani Chauke (Materials Modelling Centre) Ms Moyahabo Chuma (Materials Modelling Centre)

Co-author

Prof. Phuti E Ngoepe (Materials Modelling Centre)

Presentation Materials