In this study, the effect of sub-zero rolling, also known as cryo-rolling, on the microstructure, crystallographic texture, an‎d mechanical properties of the quaternary alloy Fe₅₀Mn₁₇Ni₁₇Cr₁₆ was investigated. The alloy was first produced by vacuum induction melting, an‎d after primary rolling an‎d annealing to eliminate casting effects, it was prepared for cryo-rolling. The cryo-rolling process was carried out at sub-zero temperatures an‎d at different strain levels. The main objective was to examine the effect of plastic deformation on the evolution of microstructure, texture, an‎d mechanical properties. For microstructural observations, optical microscopy an‎d scanning electron microscopy were employed, while texture analysis was performed using X-ray diffraction an‎d calculation of orientation distribution functions. Results showed that with increasing strain, grains became elongated an‎d shear ban‎ds were formed, which played an important role in strain localization. Moreover, the development of α-fiber texture components such as Brass an‎d Goss/Brass was observed, which intensified at higher strains. At larger strains, indications of the formation of β-fiber components also appeared, reflecting grain rotation an‎d texture evolution in various orientations. In terms of mechanical properties, shear punch testing revealed that shear strength initially increased with strain, reaching its maximum at 40% strain. However, at 75% thickness reduction, a significant dro‎p in strength was observed due to localized stress concentration an‎d the initiation of microcracks, leading to a transition in fracture behavior from ductile to brittle. Fractography confirmed this change by revealing a shift from deep dimples to flat an‎d brittle fracture surfaces. Microhardness testing further demonstrated that the alloy hardness steadily increased from its initial value of about HV 126 to HV 291 at 40% strain, before decreasing to HV 258 at 75% strain. Overall, the results indicate that cryo-rolling can enhance the mechanical strength of multicomponent alloys; however, at high strains, the risk of embrittlement an‎d degradation of mechanical properties increases. Therefore, controlling the degree of rolling an‎d optimizing processing conditions are essential to achieving desirable mechanical performance. These findings can serve as a basis for designing forming processes in high-entropy alloys an‎d other multicomponent alloy systems.

محمدرضا طرقي نژاد

احمد رضائيان , محمد رضايت