Unveiling hot deformation behavior and microstructural evolution in Fe-21Mn-10Al-(5Ni)-C alloys

The low-density alloy holds promising prospects for lightweight and energy-saving applications. An effective approach for regulating the microstructure and mechanical characteristics of low-density alloy is thermal processing. This study examines the behavior of hot deformation and microstructural evolution of Ni-alloyed low- density alloy at different deformation conditions, utilizing thermomechanical simulation and multiscale characterization. Constitutive equations for Fe-21Mn-10Al-(5Ni)-C low-density alloys were developed. After the addition of Ni, the alloy exhibits higher flow stress, and the activation energy for hot deformation increased from 424.77 kJ center dot mol-1 to 441.35 kJ center dot mol-1. Additionally, the dislocation density of the alloy increased, the grain size decreased, and the B2 phase precipitated within the alloy. Meanwhile, the interaction between dislocations and precipitates during high-temperature deformation was first investigated by high resolution transmission electron microscopy (HRTEM). The findings of this study make a significant contribution to the ongoing development of low-density alloys.