Masters Theses

Keywords and Phrases

Plasma erosion

Abstract

"Worn Hall effect thrusters (HET) show a variety of unique microstructures and elemental compositions in the boron nitride thruster channel walls. Worn thruster channels are typically created by running test thrusters in vacuum chambers for hundreds of hours. Studies were undertaken to manually modify samples of boron nitride without the use of a hall effect thruster. Samples were manually abraded with an abrasive blaster and sandpaper, in addition to a vacuum heater. Some of these samples were further exposed to a xenon plasma in a magnetron sputter device. Sandpaper and abrasive blaster tests were used to modify surface roughness values of the samples from 10,000 Å to 150,000 Å, matching worn thruster values. Vacuum heat treatments were performed on samples. These treatments showed the ability to modify chemical compositions of boron nitride samples, but not in a manner matching changes seen in worn thruster channels. Plasma erosion rate was shown to depend on the grade of the BN ceramic and the preparation of the surface prior to plasma exposure. Abraded samples were shown to erode 43% more than their pristine counterparts. Unique surface features and elemental compositions on the worn thruster channel samples were overwritten by new surface features on the ceramic grains. The microscope images of the ceramic surface show that the magnetron plasma source rounded the edges of the ceramic grains to closely match the worn HET surface. This effect was not as pronounced in studies of ion beam bombardment of the surface and appears to be a result of the quasi-neutral plasma environment"--Abstract page iv.

Advisor(s)

Rovey, Joshua L.

Committee Member(s)

Hosder, Serhat
Hilmas, Greg

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Aerospace Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2013

Journal article titles appearing in thesis/dissertation

  • Modification of boron nitride ceramic to replicate Hall effect thruster surface wear.
  • Plasma exposure of Hall effect thruster ceramic material

Pagination

xi, 89 pages

Note about bibliography

Includes bibliographical references (pages 72-74).

Rights

© 2013 Alexander John Satonik, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Rocket engines -- Thrust -- ResearchHall effectFrictional resistance (Hydrodynamics)Boron nitride

Thesis Number

T 10302

Electronic OCLC #

853271216

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