Abstract
The experimental determination of the tracer or self-diffusion coefficient as a function of composition can be quite burdensome in alloys since separate measurements must be carried out for each alloy composition. A new formalism recently developed by I.V. Belova, N.S. Kulkarni, Y.H. Sohn and G.E. Murch, based on linear response theory combined with the Boltzmann–Matano method allows determination of tracer and interdiffusion coefficients simultaneously from a single, isotope-free solid to solid diffusion couple experiment. In this study, for the first time, an experimental investigation with an analytical approach based on the new formalism has been carried out in the binary Cu-Ni system. Pure Cu and Ni thin films were deposited in between several binary diffusion couples with varying terminal alloy compositions (such as Cu, Cu-25Ni, Cu-50Ni, Cu-75Ni, Ni). Diffusion couples were then annealed at 800°C, 900°C and 1000°C. After annealing, the couples were water quenched, cross-sectioned, and prepared for compositional characterization. Scanning Electron Microscopy was employed to examine the interdiffusion zone. Energy Dispersive X-ray Spectroscopy was conducted to obtain concentration profiles for quantitative analysis. The superposition of the concentration profiles of thin film and interdiffusion were analyzed for the simultaneous determination of tracer and interdiffusion coefficients. The tracer diffusion coefficient of Cu, tracer diffusion coefficient of Ni and inter-diffusion coefficients simultaneously determined using the experimental methodology based on the novel formalism derived, and produced results consistent with previously reported values determined independently by radiotracer and interdiffusion experiments.
Notes
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Graduation Date
2018
Semester
Fall
Advisor
Sohn, Yongho
Degree
Doctor of Philosophy (Ph.D.)
College
College of Engineering and Computer Science
Department
Materials Science Engineering
Degree Program
Materials Science and Engineering
Format
application/pdf
Identifier
CFE0007368
URL
http://purl.fcla.edu/fcla/etd/CFE0007368
Language
English
Release Date
December 2018
Length of Campus-only Access
None
Access Status
Doctoral Dissertation (Open Access)
STARS Citation
Schulz, Esin, "Simultaneous Measurement of Isotope-free Tracer and Interdiffusion Coefficients in Sandwich Type Diffusion Couples" (2018). Electronic Theses and Dissertations. 6167.
https://stars.library.ucf.edu/etd/6167