Author

Esin Schulz

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.

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)

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