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One of the most difficult aspects of printing large, complex metal parts is building large overhangs without the use of support structures. When using typical gas metal arc welding techniques, the torch is kept aligned with the gravitational direction. It has been shown that the maximum overhang angle that can be achieved is roughly 25°. This maximum can be increased by using part positioner, but this adds extra system complexity, especially for creating the robot paths. It is desirable then to develop a method of printing with the torch in a Non-Gravity Aligned (NGA) direction, such that the weld pool is supported and will produce the desired weld bead. This work focuses on the development of a control scheme based on sensor feedback of the state of the weld pool to maintain a stable, desired weld pool shape and thus print more complex parts using the gas metal arc welding process.
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Framework for CAD to Part of Large Scale Additive Manufacturing of Metal (LSAMM) in Arbitrary Directions
The purpose of this research is to provide a framework for Large Scale Additive Metals Manufacturing (LSAMM) in arbitrary directions. Traditionally, slicing and path planning is done along the gravity aligned direction of a part, causing more complex geometrical shapes to have unsupported overhangs. The overhangs can be managed using a part positioner or a powder bed process. A different framework for slicing and building parts out of gravity alignment could improve current capabilities of LSAMM processes. The presented research focuses on segmenting more complex geometrical parts into gravity aligned (GA), non-gravity aligned (NGA), and transition segments to help generate toolpaths. Initial research of segment planning for complex geometrical shapes will be presented, as well as current results from builds completed at the University of Tennessee- Knoxville. The completed builds show that more consistent thermal evolution of a part based on the path sequence and torch angle results in successful builds.
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- Award ID(s):
- 1822186
- PAR ID:
- 10159189
- Date Published:
- Journal Name:
- Solid Freeform Fabrication 2019: Proceedings of the 30th Annual International Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
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- The DOI is not currently available.
