Document Type

Thesis - Open Access

Award Date

2021

Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Todd Letcher

Keywords

3D Printed Composites, Fused Deposition Modeling, Print Orientation, Thermal Conductivity

Abstract

Additive manufacturing (AM) technologies have become widely used for rapid prototyping and are beginning to be used for end-use applications. Fused Deposition Modeling (FDM) is a type of 3D printing where molten thermoplastic is extruded layer by layer to create parts. There is an increasing need for improvement and diversification of material properties to further extend the use of AM parts. AM parts have not been commonly used in heat transfer applications due to the limited availability of information on thermal conductivity of materials and the effects of printing orientation. A special apparatus was designed and built to experimentally test the thermal conductivity of various FDM materials. A variety of materials (pure polymers and composites) were tested. Samples of pure polymers such as Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol-Modified (PETG) were manufactured in a variety of orientations to test tool path effects on heat conduction through the material. Composite polymers using a PLA matrix with a varying mass fraction of copper filler, were experimentally tested for their thermal conductivities. One copper sample was sintered to remove the PLA matrix and increase conductivity. For the PLA and PETG samples, it was found that the vertical parallel print displayed the highest conductivity in both polymers and vertical [45°, -45°] in both polymers showed the lowest conductivity of all orientations. Copper composites showed increasing thermal conductivity with increasing copper filler mass fraction. Sintering copper composites was shown to increase thermal conductivity by orders of magnitude.

Library of Congress Subject Headings

Three-dimensional printing.
Thermal conductivity.
Thermoplastic composites.
Composite materials.

Number of Pages

61

Publisher

South Dakota State University

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Rights Statement

In Copyright