Doctoral Dissertations

Author

Yingqi Li

Abstract

"The application of metallic glasses has been traditionally limited to parts with small dimensions and simple geometries, due to the requirement of fast cooling during the conventional process of casting. In addition, joining metallic glass to crystalline metal is of interest for many applications that require locally tailored functions and properties, but it is challenging. This research describes a promising additive manufacturing technology, i.e., laser-foil-printing, to make high-quality metallic glass parts with large dimensions and complex geometries and to fabricate multi-material components from metallic glass and crystalline metal. In this research, Zr52.5Ti5Al10Ni14.6Cu17.9 metallic glass parts are fabricated on different crystalline metal substrates, including pure Zr metal, Ti-6Al-4V alloy, and 304L stainless steel. The dissimilar bonding between the metallic glass part and the crystalline metal substrate is studied and then improved through the use of appropriate intermediate layers. The microstructure and properties of the fabricated metallic glass parts are also investigated. The results show that Zr can form a crack-free bonding with Zr-based metallic glass owing to the formation of ductile α-Zr phase, whereas direct joining of Zr-based metallic glass to Ti alloy or stainless steel fails due to the formation of various brittle intermetallic compounds. By using Zr intermediate layers for Ti substrates and V/Ti/Zr intermediate layers for stainless steel substrates, the formation of deleterious intermetallics is suppressed and thus the bonding between metallic glass and crystalline metal is significantly improved. Additionally, fully amorphous and nearly fully dense (~99.9%) metallic glass parts with comparable mechanical properties to as-cast parts have been successfully fabricated"--Abstract, page iv.

Advisor(s)

Leu, M. C. (Ming-Chuan)
Tsai, Hai-Lung

Committee Member(s)

Chandrashekhara, K.
Homan, Kelly
Brow, Richard K.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Sponsor(s)

United States. Department of Energy
University of Missouri
Missouri University of Science and Technology. Intelligent Systems Center

Comments

This work was supported by the Department of Energy (grant number DE-FE0012272); the University of Missouri System (award number FastTrack-16002R).

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2019

Journal article titles appearing in thesis/dissertation

  • Building metallic glass structures on crystalline metal substrates by laser-foil-printing additive manufacturing
  • Building Zr-based metallic glass part on Ti-6Al-4V substrate by laser-foil-printing additive manufacturing
  • Additive manufacturing of Zr-based metallic glass structures on 304 stainless steel substrates via V/Ti/Zr intermediate layers
  • Mechanical properties of Zr-based bulk metallic glass parts fabricated by laser-foil-printing additive manufacturing

Pagination

xiv, 138 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2019 Yingqi Li, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11539

Electronic OCLC #

1105154963

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