| About this Abstract |
| Meeting |
2023 AWS Professional Program
|
| Symposium
|
2023 AWS Professional Program
|
| Presentation Title |
Additive Manufacturing of Steel-aluminum Bimetallic Structures |
| Author(s) |
Rangasayee Kannan, Yousub Lee, Dean Pierce, Kinga Unocic, Jonathan Poplawsky, Blane Fillingim, Thomas Feldhausen, William Hoffmann, Andres Marquez Rossy, Hsin Wang, Tom Lienert, Peeyush Nandwana |
| On-Site Speaker (Planned) |
Rangasayee Kannan |
| Abstract Scope |
The transportation industry is the second largest contributor to global greenhouse gas emissions. Among the total CO2 emissions from the transportation sector, 75% of the emissions come from road vehicles. With the need to reduce the CO2 emissions from road vehicles to below 1 Gt/yr by 2070, extensive research is ongoing worldwide, mainly on electrifying powertrains since 65 to 80% of automobile emissions are tailpipe emissions. It is estimated that the share of CO2 emissions from materials used in automobiles will increase to 60% by 2040. Therefore, research is needed on the materials front, especially focusing on weight reduction to reduce overall CO2 emissions from the transportation sector. Bi-metallic structures are an attractive option for automotive structures as they can take advantages of both the reduced weight of aluminum/magnesium and the strength/low cost of production of steels. Additive manufacturing is a promising technique for the fabrication of bi-metallic steel-aluminum structures. The inherently high cooling rates associated with AM process can enable refining the size of the intermetallics and can suppress the change in morphology of intermetallics from discrete globular particles to continuous film at the bi-material interface. Here we present results on the fabrication of steel-aluminum bi-metallic structures using directed energy deposition additive manufacturing. The challenges associated with the fabrication of a sharp transition from steel to aluminum are uncovered using ex-situ characterization techniques and thermo-mechanical modeling of the deposition process. It was found that the fabrication of a sharp steel-aluminum transition is challenging with extensive cracking observed at the interface. The cracking was attributed to the combined effect of residual stress development due to thermal expansion coefficient mismatch and the presence of ordered intermetallics with low ductility at the interface. Using a coupled thermodynamic and thermo-mechanical modeling approach, potential pathways to enable the fabrication of steel-aluminum bi-metallic structures using additive manufacturing are proposed. The results presented here can lay the foundation for future work on the fabrication of bi-metallic steel-aluminum structures using directed energy deposition. |
| Proceedings Inclusion? |
Undecided |