Using Displacement Sensors to Characterize Critical Powder Layers in Laser Powder Bed Fusion

Additive manufacturing (AM) allows for the creation of complex geometries that cannot be created with traditional manufacturing methods, though process quality tools are still undeveloped. Uniform powder layers are critical to the final part quality for such processes, and currently, no machine can provide objective evidence of a proper powder layer with in-process monitoring equipment. In this project, proper powder layers are currently verified by unquantifiable means. The strategy of this project was to use various sensors in tandem with the camera available within the machine to objectively distinguish between passing and failing powder layers. The specific goal of this thesis was to characterize the actual powder thickness and percent coverage with laser displacement sensors by subtracting a before and after powder deposition scan of the build plate. The laser line scanner showed promising results, but the variation within the process and data alignment strategies used were not sufficient to provide a concrete correlation for powder layer characterization. This project nonetheless sets the groundwork for further work to more objectively characterize powder layers. The rest of the project used the same unquantifiable means that are currently being used to verify powder layers. Intensity values from the onboard camera’s images were able to successfully distinguish between powder layers to be used as a powder layer verification tool.

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

2023

Author dc:creator

• Wittenbrink, Jayna

Advisor dc:contributor.advisor

• Hardt, David E.

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright MIT

Licence dc:rights.uri

• http://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/152108

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/152108