Processing-Structure-Property Relations In Phase Separated Calcium Aluminosilicate Glasses
Open Access
- Author:
- Clark, Nicholas Lamar
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- November 04, 2022
- Committee Members:
- Seong Kim, Outside Unit & Field Member
Allison Beese, Major Field Member
John Mauro, Chair & Dissertation Advisor
John Mauro, Program Head/Chair
Robert Kimel, Major Field Member - Keywords:
- Glass
Phase-sparation
Indentation Hardness
Vickers
Microstructure - Abstract:
- Nanoscale phase separation is currently being investigated as a method control the mechanical properties of glasses without compromising its transparency. For this approach to be successful, comprehensive relationships between processing and microstructure, and microstructure and hardness will be needed. The first stage of this dissertation examines the evolution of the microstructure of phase separated CAS glasses in response to thermal treatment. The microstructures are analyzed via image analysis of FESEM micrographs, and the results were used to characterize the droplet coarsening mechanisms. This information was then used to synthesize glasses with specific microstructure characteristics. Vickers indentation was used to measure the indentation hardness. The microstructure within the indents were then image and analyzed to study and characterize the mechanisms of microstructure yielding. Variations in glass hardness due to phase separation were found to arise from a combination of the yielding mechanisms and phase compositions of the microstructure. Finally, a simple model was developed which allowed for transitions between microstructure yielding mechanisms to be predicted from the initial microstructure as a function of load.