<p>Free solidification molecular dynamics simulations were used to study solute trapping behaviour in the Ni-Cu alloy system. The segregation coefficient, K, as a function of crys- tallization rate was compared with several theories of trapping and, in agreement with a model proposed by Sobolev, it was found that complete trapping (K=1) occurs at a finite velocity. In order to gain further insight into the thermodynamic and kinetic factors affect- ing solute trapping, forced velocity phase field crystal (PFC) simulations were performed on a model binary alloy. We find that the complete trapping limit only occurs if a com- bination of wave-like and diffusive dynamics equation of motion of the PFC alloy model. Finally, an amplitude expansion analysis of the PFC formulation for constant velocity so- lidification was performed and an analytic expression for the complete trapping limit and solute drag was obtained.</p> / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/13989 |
| Date | 04 1900 |
| Creators | Humadi, Harith |
| Contributors | Provatas, Nikolas, Hoyt, Jeff J., Zurob, Hatem, Materials Science and Engineering |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | dissertation |
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