Doctoral Dissertations

Keywords and Phrases

Additive Manufacturing; Aluminum; Directed Energy Deposition; Microstructural Characterization; Scalmalloy; Tensile Behavior

Abstract

"Additive manufacturing (AM) is of significant interest due to the ability to fabricate 3D components layer-by-layer. Compared with traditional manufacturing methods, AM allows for the direct fabrication of complex, intricate parts without the need for extensive machining, reducing manufacturing time and tooling costs and minimizing material waste. Aluminum alloys are highly desired for implementation via AM due to their high strength-to-weight ratios; however, there are several challenges that complicate the situation and hinder the use of aluminum alloys. One of the most challenging issues is that the desired high-strength alloys are not compatible with AM processing methods. A method to address this is to develop new alloys that are specially designed to work with AM. Scalmalloy® is an Al-Mg-Sc-Zr-based alloy that has been developed for use with the unique processing seen with AM. During AM processing, Scalmalloy® powder is melted and solidified into a supersaturated solid solution. During postprocessing heat treatment, Scalmalloy® is aged to promote nanoprecipitation of Al3(Sc,Zr) which provides strengthening by pinning grain boundaries and preventing dislocation movement. This study focused on the application of post-processing treatments for the improvement of the properties of Scalmalloy® deposits fabricated by directed energy deposition (DED). This work acts as the first stepping stone toward the ultimate goal of customized multistep heat treatments for DED-fabricated high-strength aluminum alloys"-- Abstract, p. iv

Advisor(s)

Liou, Frank W.

Committee Member(s)

Han, Daoru Frank
Miller, F. Scott, 1956-
Newkirk, Joseph William
Isanaka, Sriram Praneeth

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

2026

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 11-41, has been published in Crystals Journal.

Paper II, found on pages 42-72, is planned for submission in Progress in Additive Manufacturing Journal.

Paper III, found on pages 73-100, has been published in Materials Journal.

Pagination

xiii, 110 pages

Note about bibliography

Includes_bibliographical_references_(pages 106-109)

Rights

© 2024 Rachel Boillat-Newport , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12632

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