Work

Microgravity Containerless Solidification Enabled Phase Boundary Engineering: Improved Magnetic and Mechanical Properties in Fe-Co-B Alloy

Year: 2026

Type: article

Abstract: Containerless solidification under microgravity provides a convection-suppressed, crucible-free environment for controlling solute segregation, undercooling and microstructures. Here, an Fe-Co-B alloy was solidified aboard the China Space Station and compared with ground-processed samples of the same nominal composition. The space-processed alloy retained a body-centered-cubic Fe-Co-based structure but developed a cellular/lath-like two-phase morphology with long, straight Fe-Co-B/Fe-Co boundaries. Relative to the ground-processed sample, the space-processed sample reveals reduced B segregation, a smaller composition difference between the Fe-Co-B and Fe-Co phases, and continuous strain variation across the Fe-Co-B/Fe-Co phase boundary, indicating improved interfacial coherency. Phase-field simulations show that increasing coherency strain energy stabilizes the lath-like structure observed after space processing. Compared with its ground-processed counterpart, the space-processed sample achieves higher saturation magnetization, greatly reduced coercivity and remanence, improved magnetostriction, and enhanced plastic strain. Such improvements in magnetic and mechanical properties originate from the modified composition of the Fe-Co-B phase and the formation of more coherent phase boundaries. These features weaken domain-wall pinning, enable efficient magnetostrain transfer, and facilitate dislocation motion. The results in present work demonstrate that microgravity containerless solidification is an effective strategy for engineering phase boundaries and simultaneously optimizing the soft magnetic, magnetostrictive, and plastic properties of Fe-Co-B alloys.

Source: Review of Materials Research

DOI: 10.1016/j.revmat.2026.100349