dc.contributor.author | Frøseth, Anders G. | nb_NO |
dc.date.accessioned | 2014-12-19T11:17:55Z | |
dc.date.available | 2014-12-19T11:17:55Z | |
dc.date.created | 2003-05-09 | nb_NO |
dc.date.issued | 2003 | nb_NO |
dc.identifier | 125026 | nb_NO |
dc.identifier.isbn | 82-471-5576-1 | nb_NO |
dc.identifier.uri | http://hdl.handle.net/11250/228812 | |
dc.description.abstract | The atomic and electronic structure of bulk crystalline and solid state phases related to Al-Mg-Si (6xxx) alloys have been studied using Density Functional Theory (DFT) and total energy Tight Binding (TB).
We present a procedure for fitting a non-orthogonal total energy tight binding model to full potential Linearized Augmented Plane Wave (LAPW) DFT calculations using a stochastic global optimization algorithm and increased emphasis on the angular symmetries of the bandstructure eigenvalues. We use this method to produce a tight binding parameterization for Aluminium which gives improved predictions for the generalized stacking fault energies.
We present a method for applying ab initio calculations in the process of determining the atomic structure of the precipitate phases in Al-Mg-Si alloys. We propose atomic models for the recently identified U1 and U2 precipitate phases.
We use DFT modelling to study the electronic structure of the β, β11, U1, U2, and β precipitate phases in Al-Mg-Si alloys. We show that the β11 phase is dominated by a network of covalently bonded Si and that the U1 and U2 phases contain tetragonally coordinated Al-Si bonding networks made possible by the donation of charge from the Mg atom, while the β phase is dominated by partially ionic Mg-Si bonds. | nb_NO |
dc.language | eng | nb_NO |
dc.publisher | Fakultet for naturvitenskap og teknologi | nb_NO |
dc.relation.ispartofseries | Dr. ingeniøravhandling, 0809-103X; 2003:28 | nb_NO |
dc.subject | | en_GB |
dc.subject | Fysik | en_GB |
dc.subject | NATURAL SCIENCES: Physics | en_GB |
dc.title | Atomistic modeling of the Al-Mg-Si alloy system | nb_NO |
dc.type | Doctoral thesis | nb_NO |
dc.contributor.department | Norges teknisk-naturvitenskapelige universitet, Fakultet for naturvitenskap og teknologi | nb_NO |
dc.description.degree | dr.ing. | nb_NO |
dc.description.degree | dr.ing. | en_GB |