Static recrystallized annealing treatment-induced strength-ductility trade-off in cold-rolled Co36Fe36Cr18Ni10 multi-principal alloy

Abstract

Multi-component alloys are recrystallized with various heterogeneous microstructures to regulate their main properties. However, the production of conventionally structured alloys with high strength and superior ductility is exigent because ductility is typically deteriorated by strength enhancement. The microstructure features of alloys determine their mechanical properties. In this work, a new multi-component Co 36 Fe 36 Cr 18 Ni 10 alloy is developed. The alloy was prepared by arc melting and solidified in a Cu mold with a single face-centered cubic phase that provides an outstanding ductile matrix. The mechanical properties and microstructures were systematically investigated through tensile tests, electron backscatter diffraction, and transmission electron microscopy. The as-cast alloy was cold-rolled at 90% reduction and subsequently annealed at 700, 800, and 900 °C. The texture evolution formed numerous fine grains with stacking faults, dislocations, and nanoscale annealed twins in their interior, effectively improving the mechanical properties of the alloy. In single-phase alloys, the twins dominated the matrix and the efficiency of grain refinement achieved by annealing at 700 °C afforded strength improvement. The strength and ductility trade-off is attributed to a microstructure that combines incompletely recrystallized and recrystallized grain regions, forming a heterogeneous microstructure whose performance dimensions span from the submicron to the nanoscale. The microstructure of the fabricated multicomponent alloy was created by large-deformation cold rolling followed by low-temperature annealing treatment. The results show that heterogeneous designs can be effectively achieved by implementing simple low-temperature annealing processes with reduced energy consumption. This strategy provides a means for developing new generation structural materials with high strength and ductility. • The Co 36 Fe 36 Cr 18 Ni 10 alloy exhibits a beneficial combination of strength and ductility when annealed at 700°C. • Stacking faults, dislocation entanglement and nanotwins interactions are effective way to strengthen FCC structure alloys. • Low SFE promotes annealed twins formation and LAGB is the nucleation site for strain-induced martensitic phase transitions.