Fig. 1 a Phase diagram of CoCrMnNi-Fe system, b XRD patterns of as-cast and as-annealed specimens. The annealing was done at a range of temperatures (500-900 °C) for 2 h. (The phase diagram data were used with permission from Elsevier)

Fig. 2 a Engineering stress-strain curves of Fe60 and Fe65, b yield stress, ultimate tensile strength, and total elongation as a function of Fe, c strain hardening rate of both Fe60 and Fe65 as a function of strain

Fig. 3 EBSD inverse pole figure (IPF) and phase quick maps of specimens interrupted at various strains: a, d-1, d-2 20% true strain, b, e 28% true strain, c, f 185.5% local strain. TD refers to the tensile direction. εT denotes the true strain while εL denotes the local strain. The arrows in white color indicate nucleated α’ martensite while those in yellow indicate ε-martensite. An inset is included in d-2 to show the high resolution of nucleated α’ martensite. The green and red colors in (d-1, d-2, e, f) indicate fcc and bcc phases, respectively

Fig. 4 Phase fraction evolution in Fe65 as a function of true strain during tensile deformation

Fig. 5 a EBSD phase of fcc, bcc, and hcp after plastic deformation, b-d pole figures for fcc in {111}, {110}, and {100} planes, respectively, e-g pole figures for bcc phase in {110}, {111}, and {100} planes, h, i pole figures for hcp phase in {0002}, {2-1-10} planes. The red, green, and yellow colors represent fcc, bcc, and hcp phases, respectively