Masters Theses

Abstract

"Laser Metal Deposition (LMD) is used to construct functional parts in a layer-by-layer fashion. The heat transfer from the melt region to the solid region plays a critical role in the resulting material properties and part geometry. The heat transfer dynamics can change significantly as the layers increase, depending on the geometry of the sub layers. However, this effect is unaccounted for in previous analytical models, which are only valid for a single layer. This thesis develops a layer dependent model of the LMD process for the purpose of designing advanced layer-to-layer controllers. A lumped-parameter model of the melt pool is introduced and then extended to include elements that capture height dependent effects on the melt pool dimensions and temperature. The model dynamically relates the process inputs (e.g., laser power, material mass flow rate, and scan speed) to the melt pool dimensions and temperature. A finite element analysis is then conducted to determine the effect of scan speed and track height on the solid region temperature gradient at the melt pool solidification boundary. Experimental results demonstrate that the model successfully predicts multilayer phenomenon for two deposits on two different substrates. Finally, an investigation into the sensitivity of track width to changes in process parameters is conducted"--Abstract, page iv.

Advisor(s)

Bristow, Douglas A.

Committee Member(s)

Landers, Robert G.
Liou, Frank W.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

2012

Pagination

x, 40 pages

Note about bibliography

Includes bibliographical references (pages 38-39).

Rights

© 2012 Patrick Michael Sammons, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Manufacturing processesPulsed laser depositionHeat -- Transmission

Thesis Number

T 10647

Print OCLC #

922008236

Electronic OCLC #

922008395

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