Doctoral Dissertations

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Materials Science and Engineering

Major Professor

Peter K. Liaw

Committee Members

Hahn Choo, Chain T. Liu, Dayakar Penumadu


Bulk-metallic glasses have established a formidable presence in the scientific community in recent years, due to a number of properties that are uncharacteristic of metallically-bonded materials. One of the fundamental challenges facing researchers in this field is to develop new and improved processing methods with the ultimate goal of facilitating a large-scale industrial integration of the materials.

The research described herein is directed toward the pursuit of developing and improving upon the current state-of-the art in the science of bulk-metallic glass processing. A number of research and development projects were undertaken in this pursuit. First, the technology to process bulk-metallic glasses at the University of Tennessee was developed and successfully implemented. Second, bulk-metallic glasses were produced using aerodynamic levitation, which showed an improvement over the accessible cooling rates achievable employing other containerless-processing methods. Third, erbium was found to be a superior dopant to other rare-earth elements to neutralize the oxygen in a Zr-based glass-forming alloy. The alloy was found to form a glass in the presence of up to 16,000-atomic-ppm oxygen by microalloying with Er, with a relatively minor effect on the thermal and mechanical integrity of the materials. Fourth, metastable intermetallic phases were identified in as-cast VIT-105 alloy materials that contained oxygen, using diffraction. The diffraction study included the whole pattern fitting of diffraction from crystalline species in a BMG, an analytical approach that, if existing at all in the literature, is quite rare. Furthermore, this study included a novel approach to fitting diffraction from the glass. Fifth, oxygen-stabilized analogues to intermetallic phases were found in the superheated-liquid state. The presence of Er was found to inhibit surface reoxidation, revealing its mechanism for the neutralization of oxygen. The results were used to propose a model for heterogeneous nucleation and the so-called "overheating threshold" in the alloy.

Files over 3MB may be slow to open. For best results, right-click and select "save as..."