Unique phase transformation in high entropy alloy films driven by size and stress

YF Zhao and B Chen and YJ Zhang and YQ Wang and YH Gao, JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T, 39, 2597-2605 (2025).

DOI: 10.1016/j.jmrt.2025.10.010

In this work, the phase stability of Fe50Mn30Co10Cr10 and Fe50Mn30Co10Ni10 high entropy alloy (HEA) films and their mechanical properties was studied. During non-equiatomic magnetron sputtering deposition, the sizedriven FCC-to-HCP phase transformation is observed in both single HCP-phase Fe50Mn30Co10Cr10 and HCP/ FCC dual-phase Fe50Mn30Co10Ni10 films compared to their bulk siblings. The phase structure of Fe50Mn30Co10Cr10 films remain unchanged after deformation, due to the bidirectional transformation. While the stressdriven HCP-to- FCC phase transformation is observed in Fe50Mn30Co10Ni10 films, which is explained in terms of the nucleation of stacking faults, serving as the nuclei for phase transformation. Furthermore, the Fe50Mn30Co10Ni10 films possess higher hardness than Fe50Mn30Co10Cr10, which is attributed to the transformation strengthening and abundant stacking faults/nanotwins. The current work provides a new pathway to tailor the size-induced and stress-induced phase transformation and thereby synthesize high strength metallic materials.

Return to Publications page