Directed Energy Deposition and Powder Bed Fusion of AlSi10Mg for Fabrication of Novel Transducer Components
Open Access
- Author:
- Eadie, Christopher
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- February 29, 2020
- Committee Members:
- Richard Joseph Meyer, Jr., Thesis Advisor/Co-Advisor
Jayme Scot Keist, Committee Member
Todd Palmer, Committee Member
Kenneth C Meinert, Jr., Committee Member
John C Mauro, Program Head/Chair - Keywords:
- AlSi10Mg
aluminum
directed energy deposition
powder bed fusion
tonpilz
transducer
topology optimization
parameter development - Abstract:
- In this thesis, the goal was to develop an iterative design workflow for additive manufacturing of electroacoustic component parts. The Tonpilz transducer head mass was chosen for optimization because it is required to be light and stiff, and is typically made from aluminum. Additive manufacturing excels at reducing component weight while maintaining structural rigidity thanks to the complex geometries that can be achieved. Further, AlSi10Mg, a weldable aluminum alloy, is readily printable via powder bed fusion. The head mass was optimized geometrically using internal lattice structures as well as modal simulations coupled with topology optimization. The resulting designs were manufactured via powder bed fusion and characterized to compare their performance to the standard component. It was found that the solid topology optimized head mass was successful in increasing the frequency of the relevant vibrational mode, indicating an increase in stiffness-to-weight ratio. To begin exploring the future possibility of using composites and functionally graded materials in transducer devices, AlSi10Mg was printed via directed energy deposition from three machines. For comparison, the resulting materials were characterized to observe their microstructure and mechanical properties. The best-performing aluminum in terms of stiffness and strength came from the DMG Mori Lasertec 65 3D hybrid, although none of the directed energy deposition aluminum compared well to the powder bed fusion aluminum, indicating that more work needs to be done to improve powder flow consistency and reduce defects in directed energy deposited AlSi10Mg. Therefore, it was concluded that powder bed fusion was a superior manufacturing method for the head mass, and further process improvements are required to make composites and functionally graded materials via directed energy deposition viable in the case of electroacoustic component parts.