Luiz Pereira defends his PhD in Numerical Mechanics and Marerials on Nov. 12th, 2020.
He worked on the mechanisms of oxygen bubble formation in a glass melt in the nuclear waste vitrification context.
His thesis was supervised by Franck Pigeonneau, CFL team in the framework of a project with CEA.
Abstract of his work:
The objective of this project is to determine quantitative parameters inducing the bubble nucleation (gas solubility, supersaturation and nucleation). The impact of the molten glass composition (redox) and temperature will be deeply investigated. Moreover, the role of heterogeneities present in the melt and which may promote nucleation phenomena will be considered. A specific experimental set-up will be implemented in order to in-situ monitor the bubbles formation associated with a molten glass redox state measurement. Post-mortem analyzes on the solidified material will also be performed (electronic microscopy, gas analyzes). In a second step, a basic modelling of the bubble nucleation may be considered using the previously acquired experimental results.
On the left, a population of bubbles in a borosilicate melt at 1200°c, in situ camera imaging device
On the right,a population of bubbles in a borosilicate melt at 1050°c, optical microscopy