Thermal Deformation Behavior and Processing Map of a Novel CrFeNiSi0.15 Medium Entropy Alloy

The thermal deformation behavior of a novel CrFeNiSi0.15 medium entropy alloy (MEA) was studied via isothermal compression experiments, with the processing parameter range of 900-1200 degrees C and 0.001-1 s(-1). According to experimental data, the modified constitutive equation had been obtained, which precisely predicted the flow behavior of CrFeNiSi0.15 MEA during thermal deformation. At the same time, the processing map was established on the basis of the dynamic material model (DMM) theory. According to the map, the optimal processing parameters were determined at 1130-1200 degrees C/0.06-1 s(-1), under which the power dissipation efficiency could reach above 34%. The peak efficiency was above 38%, which occurred at 1200 degrees C/1 s(-1). In such parameter, complete dynamic recrystallization (DRX) also occurred. The flow instability of CrFeNiSi0.15 MEA was estimated to occur at 900-985 degrees C/0.12-1 s(-1), which was shown as grain boundaries cracking. Furthermore, both the continuous DRX (CDRX) and discontinuous DRX (DDRX) occurred simultaneously during thermal deformation. Meanwhile, some twins were also newly formed during DRX process, most of which were primary twins. The occurrence of twinning was beneficial to promote the development of DRX behavior.

Automated summary

The thermal deformation behavior of CrFeNiSi0.15 MEA was studied through isothermal compression experiments and a modified constitutive equation was obtained. The processing map based on the dynamic material model (DMM) theory was established, revealing the optimal processing parameters for power dissipation efficiency and peak efficiency. The occurrence of dynamic recrystallization (DRX) and twinning during thermal deformation was also observed.