Masters Theses

Keywords and Phrases

304L stainless steel; Bulk metallic glass; Plasma spheroidization; Powder characterization; Vitreloy 106A

Abstract

"There are many processes that use metal powder as the starting material for the production of parts. With the growth of these manufacturing techniques, more critical part applications are being considered. In order to fully understand the process and create consistent parts, powder properties need to be well understood. Selective laser melting (SLM) is a powder bed-based additive manufacturing process. During processing, heat-affected powders are generated and can deposit within the build area. The current work investigated the characterization of heat-affected 304L stainless steel powder using techniques such as scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to detect differences in the heat-affected powder and to determine the best way to detect them. This heat-affected powder can also have an influence on the amount of times that the powder can be reused. A methodology was proposed where a fast, miniature powder recycling study was conducted. Area fractions and part spacing where deterioration of powder was observed can then be used to design a more in depth recycling study. The use of SLM for processing of more exotic materials such as metallic glasses was also of interest. However, the acquisition of powder forms of these materials that are suitable for processing via SLM is difficult and expensive. The work in this thesis aimed to use plasma spheroidization to tailor inert ground, angular Vitreloy 106A metallic glass powder and spheroidize it so that it was suitable for use in additive manufacturing processes. Several powder characterization techniques were used to evaluate the success of the process including x-ray diffraction, differential scanning calorimetry and Raman spectroscopy"--Abstract, page iv.

Advisor(s)

Newkirk, Joseph William

Committee Member(s)

Liou, Frank W.
Bartlett, Laura

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering

Sponsor(s)

United States Department of Energy
Honeywell Federal Manufacturing and Techologies, LLC

Comments

This work has been funded by Honeywell Federal Manufacturing & Technologies under Contract No. DE-NA0002839 with the U.S. Department of Energy.

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2018

Journal article titles appearing in thesis/dissertation

  • Investigation of heat-affected 304L SS powder and its effect on built parts in selective laser melting
  • Effects of area fraction and part spacing on degradation of 304L stainless steel powder in selective laser melting
  • Plasma spheroidization of Vitreloy 106A bulk metallic glass powder

Pagination

xi, 82 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2018 Caitlin Shea Kriewall, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 11427

Electronic OCLC #

1084478408

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