Phase separation and crystallization of complex borosilicate melts for glass-ceramic waste forms

Abstract

Roberts received his Masters' Degree in MSE in December 2018, and this report is based on his thesis for that degree, "Microstructural Development and Its Effect on Aqueous Corrosion of a Borosilicate Glass Ceramic for Waste Vitrification." Paul Porter is a candidate for a PhD in MSE, expected in 2020. His contributions to this study are included in this report. Both students, as well as a number of undergraduate assistants, were supervised by Prof. Richard K. Brow. The report is divided into four sections. The first provides background information about issues associated with waste vitrification, and the development of the borosilicate glass-ceramic materials. The second section describes the effects of thermal history on the phase transformations that occur in the borosilicate glass-ceramic and includes the results of both isothermal and continuous-cooling experiments. The third section describes the effects of thermal history on the chemical durability of the borosilicate glass-ceramics, and includes the results of product consitancy tests performed at Missouri S&T and at Savannah River National Lab. Sections 2 and 3 are written in the form of journal articles. The fourth section is an appendix that includes a description of the hot thermocouple test assembly, as well as data sets used in the first two sections.