A thermally-driven design methodology for large-scale polymer additive manufacturing systems

The extrusion additive manufacturing (AM) process involves selectively dispensing melted material out of a nozzle onto a build platform to form a layer, moving the build platform down, and extruding the next layer. The strength of polymer welds between layers of extrusion AM parts is lower than the strength of the bulk material itself. These welds are formed when a new layer heats the previous layer enough to initiate the diffusion of polymer macromolecules between layers [1]. To obtain acceptable adhesion between two layers, the temperature of the interface between layers must remain high enough for a long enough period of time to drive the diffusion process. Inter-layer welding is of special concern in large-scale extrusion processes, as the large thermal gradients induce residual stresses that can overcome weak inter-layer welds, causing warping and cracking [2].

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Kurfess, Rebecca(Rebecca Ann)

Advisor dc:contributor.advisor

• Anastasios John Hart.

• Mechanical Engineering.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/123748

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/123748