Deformation-induced interfacial-twin-boundary ?-phase in an Fe48Mn37Al15 body-centered cubic metastable alloy

•The deformation mechanism of Fe48Mn37Al15 body-centered cubic metastable alloy has been systematically investigated.•A distinct atomic unit cell of ω-phase is obtained by HRTEM in Fe48Mn37Al15 alloy.•A deformation-induced interfacial-twin-boundary ω-phase is firstly proven to be formed in a Fe48Mn37Al15 alloy during the compression process.•The crystallographic orientation relationship with bcc and matrix and ω-phase has been analyzed.