Masters Theses

Abstract

"Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technology that is capable of fabricating complex three-dimensional parts. FEF works by depositing an aqueous-based colloidal ceramic or metal paste in a layer-by-layer fashion below the freezing point of the aqueous medium as to rapidly freeze the paste. The FEF machine in the present study is equipped with three syringes and is capable of mixing each paste in a desired composition ratio by using an inline static mixer. Compensation for the transport delay caused by the static mixer is necessary; therefore, an algorithm was developed to apply a one-dimensional (1D) composition gradient to monolithic parts, adjusting the plunger velocities to account for the transport delay.

Control of extrusion-based additive manufacturing techniques is difficult due to the uncertainties of the paste properties such as entrapped air bubbles, inhomogeneity, and inconsistency of the paste rheology from batch to batch. Other challenges are present such as starting and stopping extrusion on demand (EOD) and steady-state velocity control of a coupled triple extruder system. These issues have been addressed with the development and implementation of a hybrid extrusion force-velocity controller"--Abstract, page iv.

Advisor(s)

Leu, M. C. (Ming-Chuan)

Committee Member(s)

Landers, Robert G.
Hilmas, Greg

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Sponsor(s)

National Science Foundation (U.S.)
Boeing Company
Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio)
Missouri University of Science and Technology. Center for Aerospace Manufacturing Technologies
Universal Technology Corporation

Comments

Funded by the National Science Foundation contract CMMI-0856419 with matching support from the Boeing company through the Center for Aerospace Manufacturing Technologies at the Missouri University of Science and Technology, and by the Air Force Research Laboratory contract 10-S568-0094-0l-Cl through the Universal Technology Corporation

Publisher

Missouri University of Science and Technology

Publication Date

2012

Journal article titles appearing in thesis/dissertation

  • Process Planning and Control for Functionally Graded Material Fabrication Using Freeze-form Extrusion Fabrication
  • Hybrid Extrusion Force-Velocity Control Using Freeze-form Extrusion Fabrication for Functionally Graded Material Parts

Pagination

x, 55 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2012 Bradley Kenneth Deuser, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Solid freeform fabrication
Ceramics -- Extrusion
Pulsed laser deposition

Thesis Number

T 10545

Print OCLC #

903592760

Electronic OCLC #

903648608

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