Degree Type

Thesis

Date of Award

1-1-2002

Degree Name

Master of Science

Department

Materials Science and Engineering

Major

Materials Science and Engineering

Abstract

An examination of the effects of oxygen contamination on the structure of thermally sprayed coatings of Cu47Ti33Zr11Ni8Si1 was performed. Plasma arc sprayed coatings were made from Cu47Ti33Zr11Ni8Si1 gas atomized powders using both air plasma spray and vacuum plasma spray methods. Starting powders with oxygen levels from 0.125 - 0.79 wt.% were deposited onto thin 1080 mild steel coupons for metallographic evaluation and determination of changes to the structure of the material as a result of the thermal spray environment and powder oxygen content. Coating conditions were selected for further evaluation and were deposited onto 304 stainless steel substrates for testing in a cavitation erosion environment. Samples were evaluated for mass loss rate and time to failure using a modification of ASTM G32-92. The structure of the coatings was found to depend primarily on the spray environment, with a reduced-pressure argon environment producing coatings with the highest fraction of amorphous structure for a given starting powder. These coatings also displayed a weak pattern of higher resistance to cavitation erosion damage than those which were air plasma sprayed from the same starting powders. Coating failure was found to be due to features inherent to thermally sprayed coatings rather than differences in the amorphous structure of the coatings.

DOI

https://doi.org/10.31274/rtd-20200723-0

Copyright Owner

Matthew Frank Besser

Language

en

OCLC Number

50059078

File Format

application/pdf

File Size

52 pages

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