October 2024

Journal

Controlling microstructure and B2 ordering kinetics in Fe–Al system through additive manufacturing

By:
Kannan, Rangasayee ; Pierce, Dean T; Lee, Yousub ; Poplawsky, Jonathan D; Unocic, Kinga A; Fancher, Christopher M; Hoffman, William; Lienert, Tom; Nandwana, Peeyush
Journal Name:
Journal of Materials Research and Technology
Page Number:
1692-1703
Volume:
33
Publication Date:
October 7, 2024
View DOI Listing:
https://doi.org/10.1016/j.jmrt.2024.09.103

Abstract

Multi-material fabrication between steel and aluminum is challenging because of the formation of several intermetallic phases. Embrittling B2 ordered intermetallics form in the steel rich side and are stable till about 60% of Al dilution in steel. In this work by using multi-length scale characterization coupled with integrated computational process and thermokinetic modeling, we show that the ordered B2 intermetallics in the steel rich side of the Fe–Al system forms via a nucleation and growth mechanism. The extent of B2 ordered intermetallics can be controlled by modifying the directed energy deposition-additive manufacturing (DED-AM) process parameters. Our findings lay the foundation for enabling fabrication of crack-free functionally graded compositions between the two alloys.