Degree Type
Dissertation
Date of Award
1986
Degree Name
Doctor of Philosophy
Department
Materials Science and Engineering
Abstract
A three stage heat transfer is employed to eliminate the tin ball-up problem. A void nucleation problem is encountered in stage I and it can be reduced by minimizing time at stage I. Therefore, T(,d), the tin depletion time, is important in order to minimize time at stage I. Experiments on stage I heat treatment in three geometrical conditions, planar, internal tin and external tin, are studied in order to determine T(,d) values. The depletion of tin layer is proportional to the square root of time for the planar and external tin cases. A finite-difference numerical analysis is applied to study these three geometrical conditions. The numerical model predicts T(,d) values slightly less than the experimental results. Possible causes of disagreement have been discussed. The results show that the planar geometry is the upper bound solution of the external tin wire condition and the internal tin wire condition is the lower bound solution of the external tin wire condition.
DOI
https://doi.org/10.31274/rtd-180813-5718
Publisher
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Copyright Owner
Chann-Chen Cheng
Copyright Date
1986
Language
en
Proquest ID
AAI8615032
File Format
application/pdf
File Size
107 pages
Recommended Citation
Cheng, Chann-Chen, "The analysis of tin diffusion steps in the preparation of Nb3Sn-Cu superconductors " (1986). Retrospective Theses and Dissertations. 7985.
https://lib.dr.iastate.edu/rtd/7985
