Masters Theses

Jie Li

Keywords and Phrases

Additive manufacturing; Al2O3; Extrusion freeform fabrication

Abstract

"In order to understand the effect of fabrication temperature, a computer controlled 3-D gantry system was used to extrude aqueous alumina paste using Extrusion Freeform Fabrication. The system includes a temperature control subsystem that allows for fabrication of components below the paste's freezing temperature in the range of -10⁰C to -30⁰C and a hot plate with temperature in the range of 20⁰C to 80⁰C inside a room temperature chamber. Comparisons in terms of relative density, mechanical properties, part accuracy and minimum deposition angle were performed by Extrusion Freeform Fabrication at 40⁰C plate temperature inside a room temperature chamber and at -20⁰C plate temperature with a -20⁰C chamber temperature.

The parts fabricated at 40⁰C were able to achieve relative density, Young's modulus and flexure strength as high as 96.73%, 311 GPa, and 338 MPa, respectively; the minimum deposition angle achieved was 50⁰ at 38 mm bottom diameter and the parts had 7-14% shrinkage after sintering. In comparison, for the parts fabricated at -20⁰C, the average relative density, Young's modulus and flexure strength obtained were 91.55%, 280 GPa, and 300 MPa, respectively; parts could be fabricated with a 24⁰ minimum deposition angle at 64 mm bottom diameter and had 10-16% shrinkage after sintering. The hardnesses of parts fabricated at 40⁰C and fabricated at -20⁰C were 16.78 GPa and 14.36 GPa, respectively. Microstructures were studied by using SEM to obtain a deeper understanding of the fabrication temperature effect."--Abstract, page iii.

Advisor(s)

Leu, M. C. (Ming-Chuan)

Committee Member(s)

Hilmas, Greg
Landers, Robert G.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2015

Pagination

viii, 39 pages

Note about bibliography

Includes bibliographical references (pages 37-38).

Rights

© 2015 Jie Li, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Solid freeform fabricationCeramics -- ExtrusionRapid prototypingAluminum oxide -- Thermal properties

Thesis Number

T 10681

Electronic OCLC #

913486430

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