Date of Award
Doctor of Philosophy (PhD)
Chair and Committee
Kenneth F Kelton
In the study of the glass transition, the properties of high temperature liquids in their equilibrium and supercooled states may provide clues to the question of why certain compositions form glasses more easily than others. In metallic alloys such measurements are difficult due to the high reactivity and high melting temperatures of these liquids. Levitation methods provide a solution this problem by isolating liquid alloys from their environments. Here, the techniques of data acquisition and analysis for thermophysical property measurements under electrostatic levitation are presented, with demonstrative examples from select compositions from the Cu-Zr system. The development of techniques and software for the analysis of X-ray diffraction data acquired using electrostatic levitation is also discussed and applied to amorphous Zr58.5Cu15.6Ni12.8Al10.3Nb2.8. The results of systematic studies of density and viscosity as a function of temperature in Cu100 − xZrx: x = 30 – 55) reveal maxima in thermal expansion coefficient and kinetic strength at the best compositions of the alloy system. Interpretation of these results predicted a temperature dependence of the thermal expansion coefficient on supercooling. This prediction was confirmed by high precision measurements of density in Zr58.5Cu15.6Ni12.8Al10.3Nb2.8 and Zr57Cu15.4Ni12.6Al10Nb5 on cooling through the glass transition during electrostatic levitation.
Bendert, James Christopher, "Thermophysical and Structural Measurements of Liquid Metallic Alloys Using Electrostatic Levitation" (2013). All Theses and Dissertations (ETDs). 1100.