Doctoral Dissertations

Author

Lan Li

Keywords and Phrases

Additive Manufacturing; FEA simulation; Material characterization; Residual stress

Abstract

"Laser Metal Deposition (LMD), also called as, Laser Engineered Net Shaping (LENS), Directed Energy Deposition (DED), is a typical Additive Manufacturing (AM) technology, is used for advanced free-form fabrication. It creates parts by directly melting materials and depositing them on the workpiece layer by layer. In this process, the metal powder or fiber is melted within the melting pool by laser beam or electron beam and quickly solidifies to the deposited layer. LMD technology shows great advantages over traditional manufacturing on complex structure fabrication, including high building rates, easy material replacement and reduced material waste. These merits make the wide application of this technology in industry, such as new components fabrication and parts repairing manufacturing, coatings, rapid prototyping, tooling, repair, etc.

The proposed project is to investigate the key parameters to improve the mechanical properties of different fabricate parts in LMD manufacturing by combined approach of experimental analysis and FEA simulation method. Therefore, several sets of experiments will be designed to reveal the processing parameters on properties of deposited components in the method of LMD process. The microstructure, Vickers hardness, phase identification, tensile properties of LMD parts are measured to investigate the fabricated qualities. The features of thermal stress and deformation involved in the DMD process were predicted by the FEA model. This work helps to fully study the thermal analysis to analyze the temperature profile, cooling rate and temperature gradients on microstructure and residual stress, which further influences the engineered mechanical properties of build parts"--Abstract, page iv.

Advisor(s)

Liou, Frank W.

Committee Member(s)

Midha, A. (Ashok)
Wang, Cheng
Isaac, Kakkattukuzhy M.
Adekpedjou, Akim

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Comments

This dissertation was supported by the Laser Aided Manufacturing Processes (LAMP) Laboratory, and Center for Aerospace Manufacturing Technologies (CAMT), which are gratefully acknowledged.

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2021

Journal article titles appearing in thesis/dissertation

  • An efficient predicting modelling for simulating part- scale residual stress in laser metal deposition process
  • Temperature and residual stress distribution of FGM parts by DED process: Modelling and experimental validation
  • Reconstruction algorithm in laser-aided direct metal deposition repair of damaged gear
  • Experimental and numerical investigation in directed metal deposition for component repair

Pagination

xiv, 141 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2021 Lan Li, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11907

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