Influence of Cold Rolling on the Microstructure and Mechanical Properties of FeCoCrNiMn High-Entropy Alloy

This study delved into the influence of room temperature rolling on an FeCoCrNiMn high-entropy alloy. Initially, the alloy was synthesized via vacuum induction melting and subsequently homogenized at 1100 degrees C for a duration of 6 hours. Cold rolling, with thickness reduction of up to 85%, significantly altered the material's microstructure. It led to increased dislocation density, elongation of initial grains in the rolling direction, formation of shear bands, and twinning within the grains. As deformation intensified, the alloy exhibited enhanced mechanical properties. Specifically, hardness, yield strength, and ultimate strength rose, while elongation decreased. Remarkably, with an 85% thickness reduction, the tensile strength reached 1268 MPa-approximately 2.7 times higher than that of the as-cast counterpart. Additionally, scanning electron microscopy (SEM) examinations of the fracture surface revealed a transition from ductile-to-brittle fracture mode as thickness reduction occurred.