Doctoral Dissertations

Keywords and Phrases

Additive Manufacturing; Coaxial Laser Wire Deposition; Defect Analysis; Directed Energy Deposition

Abstract

This work seeks to improve the usability and capability of coaxial wire-based laser metal deposition (LMD) through the experimental study of process parameters on output geometry, directional effects, and defect formation. Wire-based LMD is a directed energy deposition (DED) strategy that uses a focused laser heat source to melt and fuse metal wire as it is deposited. This process is used to build parts layer-by-layer until a desired geometry is accomplished. LMD enables the creation of complex components at a high build rate with low material and energy waste. This work focuses on the deposition of titanium wire in the creation of aerospace components, as a replacement to traditional manufacturing methods like forging and casting. The effects of process parameters like traverse feed rate and workpiece illumination proportion (WIP) are characterized in this work, with the aim of optimizing these parameters to achieve defect-free deposits. Over the experimentally tested ranges, the single bead aspect ratio was significantly increased, and the deposited material's defect volume percentage was reduced from 1.021% to 0.062%. Additionally, the bead geometry produced by the three-beam coaxial strategy was proven to be directionally independent. Though the work is focused on wire DED, the presented ideas and methodology can be extended to other additive manufacturing (AM) processes.

Advisor(s)

Liou, Frank W.

Committee Member(s)

Chandrashekhara, K.
Dharani, Lokeswarappa R.
Leu, M. C. (Ming-Chuan)
Isanaka, Sriram Praneeth
Sparks, Todd E.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2025

Journal article titles appearing in thesis/dissertation

Paper I: Pages 10-36 have been published in Materials, Design and Application of Additive Manufacturing: Volume II.
Paper II: Pages 37-60 have been published in Materials, Rising Starts in Additive Manufacturing.
Paper III: Pages 61-83 have been submitted to Metals, Additive Manufacturing and Processing of Metallic Alloys and Composites.

Pagination

xi, 88 pages

Note about bibliography

Includes_bibliographical_references_(pages 86-87)

Rights

© 2025 Remy Mathenia , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12514

Download

Share

 
COinS