Aluminum Alloy Development for Hybrid Wire Arc Additive Manufacturing
Abstract
The proposed study will allow faculty and graduate students at Johns Hopkins University to team with scientists and engineers in the Additive Manufacturing Branch at the Naval Surface Warfare Center, Carderock Division (NSWCCD). Additive Manufacturing (AM) is widely regarded as a transformative manufacturing process that has the potential to displace traditional casting and forging processes in the production of a wide variety of naval components and structures. To date, the vast majority of studies on metal AM have focused on powder bed processes, but the collaboration outlined in this proposal will focus on wire arc additive manufacturing (WAAM) andthe development of novel aluminum alloys that will enable grain refinement, mitigate hot cracking, enhance weldability/printability, and increase elevated temperature performance. The scientific drivers for this study are based on the hypothesis that the use of nanoscale precipitates, and/or particles, as inoculants will result in fine-grained equiaxed WAAM microstructures. The hypothesis itself is predicated on recent studies that have demonstrated that nanoparticles and ultrafine Al(Fe,Mn)Si precipitates have resulted in significant microstructural improvements during laser powder bed fusion (LPBF) of aluminum alloys. Translating these benefits fromLPBF to WAAM will require both familiarity and control of salient WAAM processing parameters and a fundamental understanding of theinfluence that alloy chemistry has on precipitation pathways and microstructural evolution. NSWCCD has extensive technical expertise in welding and wire-arc manufacturing and will print single- and multi-walled WAAM specimens using a matrix of carefully controlled print parameters. These specimens will undergo detailed microstructural and mechanical property characterization at Johns Hopkins using state-of-the-art microscopy and microanalysis tools available at JHU and custom small-scale and scale-specific load frames that the PI#s group hasdeveloped. The processing and characterization will be conducted in parallel, and rapid feedback loops will be used to hone the WAAM parameters. The project will start with commercially available wires, but custom wire compositions will be developed using ICME-based models and rapid microstructural feedback. JHU will also evaluate the microstructural stability and elevated temperature tensile and creep properties of the new WAAM-printed aluminum alloys. The introduction of nanoscale precipitates and particles has the potential to increase both stability and properties. The technological drivers for, and anticipated DOD benefits to be derived from, the proposed study includes the pressing need for agile on-demand manufacturing of large-scale aluminum naval components with complex shapes that can be made close to the point of need. WAAM systems are well suited for expeditionary environments and highly relevant to Navy needs. Furthermore, extending the operating temperatures of aluminum to 400°C will greatly increase its usefulness as a low cost, light weight, structural material. - Approved for Public Release -
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412512
Entities
People
- Kevin Hemker
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy