The Recrystallized Microstructures and Mechanical Properties of a Hypo-Eutectic AlNiCrFeMo High-Entropy Alloy.

Recrystallization is a critical process for tailoring the microstructure to enhance the mechanical properties of alloys. In duplex-phase alloys, the recrystallization is different due to the influence of the second phase. Hypo-eutectic high-entropy alloys (HEAs) with two phases are promising structural materials. Understanding the laws of microstructure and mechanical properties during recrystallization is essential for fabrication and application. Here, we systematically investigate the influence of recrystallization time on the microstructure and mechanical properties of an as-cast hypo-eutectic high-entropy alloy (HEA), AlNiCrFeMo. As the recrystallization time increases from 10 min to 8 h at 1100 °C, the cold-rolled alloy gradually completed the recrystallization process with a residual large B2 phase and equiaxed FCC grains decorated with B2 precipitation. The average grain size of the FCC phase increases slightly from 2.60 μm to 3.62 μm, while the fine B2 phase precipitates along the FCC phase's grain boundaries. This optimized microstructure significantly improves the alloy's tensile strength from 422 MPa to 877 MPa, while maintaining a substantial plasticity of 41%, achieving an excellent strength-ductility balance. These findings provide useful information for regulating the industrial thermomechanical treatment of dual-phase hypo-eutectic high-entropy alloys.