# Shanghai Jiao Tong University Stabilizes Fe3Al 3D Printing at 105–125 A

- Published: 2026-11-07 03:21 UTC
- Section: Machines & Making › Materials science
- Tags: twin-wire directed energy deposition, Fe3Al alloy, in-situ carbides, deposition current, tensile anisotropy
- URL: https://realtech.media/news/rt-95bc922b5b149543a298a1a2_shanghai_jiao_tong/

**Researchers demonstrated that in-situ Fe3AlC0.5 carbides stabilize the grain structure of Fe-30Al-0.3C-Si-Mn alloy across varying deposition currents in a laboratory prototype setup.**

![Shanghai Jiao Tong University Stabilizes Fe3Al 3D Printing at 105–125 A](https://realtech.media/media/2026/11/dae4d1304dbefb0f.jpg)
*U.S. Air Force photo by Airman Hannah Bench, Wikimedia Commons, Public domain*

In a study published in China Welding (中国焊接：英文版), researchers from Shanghai Jiao Tong University and collaborating institutions analyzed the effect of deposition current on the microstructure and mechanical performance of Fe-30Al-0.3C-Si-Mn alloy fabricated via twin-wire directed energy deposition-arc (TW-DED-arc) [1]. The team printed 50-layer laboratory samples using separate steel and aluminum wires fed simultaneously into a single molten pool at three current levels: 105 A, 115 A, and 125 A.

## Microstructure and Carbide Evolution

Iron-aluminum alloys based on Fe₃Al are prone to room-temperature brittleness, and repeated thermal cycling during additive deposition typically destabilizes grain structure. During the TW-DED-arc process, in-situ Fe₃AlC₀.₅ carbide precipitates formed directly within the Fe₃Al matrix [1]. Although higher deposition currents raised the molten pool temperature and total heat accumulation, the carbide particles promoted grain nucleation and restricted grain growth across all tested parameters [1]. As current increased, the carbides enlarged and distributed continuously along grain boundaries, but average microhardness remained relatively stable.

## Mechanical Properties and Anisotropy

Tensile testing demonstrated that the alloy's strength and directional anisotropy vary independently with current adjustments [1]. At 115 A, the alloy achieved its highest tensile strengths of approximately 431 MPa in the horizontal direction and 327 MPa in the vertical direction [1]. However, this condition also showed the largest difference between the two orientations. Increasing the current to 125 A reduced tensile anisotropy, though it did not yield higher overall tensile strength [1]. The authors concluded that in-situ carbide formation expands the viable processing window for wire-arc additive manufacturing of iron aluminides.

## Sources

1. [中国焊接：英文版](https://doi.org/10.1016/j.cwe.2026.100073)
2. [EurekAlert](https://www.eurekalert.org/news-releases/1150760)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-95bc922b5b149543a298a1a2_shanghai_jiao_tong/