Effect of warm-rolling and annealing on the microstructure and mechanical properties of dual-phase Al0.45CoCrFeNiTi0.25 high-entropy alloy

Abstract

This study investigates the impact of warm-rolling and subsequent annealing on the microstructure and tensile properties of a dual-phase Al0.45CoCrFeNiTi0.25 high-entropy alloy (HEA) containing both face-centered cubic and body-centered cubic phases. The HEA underwent warm-rolling at temperatures of 450, 600, and 750 °C with a 50% reduction in thickness, followed by annealing at various temperatures. Higher warm-rolling temperatures facilitated the precipitation of B2 particles, significantly influencing the alloy's phase distribution. Throughout the experiments, no new phases emerged, and annealing maintained the alloy's original phase composition.Warm-rolling at 450 °C, followed by annealing at 1200 °C, led to substantial microstructural changes, including the formation of distinctive annealed twins. These microstructural changes enhanced ductility significantly, increasing elongation to 13.4% (a 538% improvement over the as-cast state) while maintaining a fracture strength of 983 MPa. Overall, this comprehensive analysis demonstrates that optimizing the warm-rolling and annealing parameters can significantly enhance the properties of dual-phase HEA.

Keywords

• Al0.45CoCrFeNiTi0.25 HEA
• Warm-rolling
• Annealing
• Mechanical properties
• Strengthening mechanisms