Effect of cold-rolling and annealing temperature on microstructure, texture evolution and mechanical properties of FeCoCrNiMn high-entropy alloy

This study investigates the effects of cold rolling and annealing on the microstructure, texture, and mechanical properties of FeCoCrNiMn high-entropy alloys. Utilizing vacuum induction melting, the alloy was initially cast into ingots and hot-rolled into plates, which were subsequently cold-rolled to various thicknesses and annealed at different temperatures. Microstructural analyses were conducted using X-ray diffraction and electron backscatter diffraction techniques, revealing a persistent face-centered cubic structure across all conditions. The texture evolution demonstrated a shift from Copper and S components to dominant Goss and Brass components as cold rolling intensified, suggesting the formation of Brass-type texture in FeCoCrNiMn at high deformation. Mechanical testing showed that the alloy's yield and tensile strengths significantly increased with cold rolling, reaching optimum values at similar to 66 % reduction. Annealing at 750 degrees C enhanced both strength and ductility, primarily through grain refinement and the formation of Sigma 3 annealing twin boundaries, which dominated the microstructure of recrystallized grains. The study confirms that the low stacking fault energy of the alloy facilitates the activation of twinning and transformation-induced plasticity mechanisms, crucial for the observed enhancements in mechanical properties.