Microstructure and properties of FeCoNi1.5CuB0.5Y0.2 high-entropy alloy subject to high magnetic field treatment

Abstract

FeCoNi_1.5CuB_0.5Y_0.2 high-entropy alloys (HEAs) were prepared through cold isostatic pressing and microwave sintering, followed by treatment with high-pulsed magnetic field treatment. This study investigated the structure, microstructure, and mechanical properties of HEAs under different magnetic field processing parameters (magnetic induction intensity, number of pulses). The results indicated that the application of the pulsed magnetic field led to the transformation of a portion of the face-centered cubic phase, which served as the matrix, into the hexagonal close-packed phase and M₃B phase. This transition was accompanied by the proliferation and movement of dislocations, leading to increased dislocation density and improved plastic deformation ability of the alloy. At a magnetic induction intensity of 1T and 120 pulses, the alloy exhibited the highest strength and toughness. Particularly, HEAs exhibited a compressive strength, maximum compression ratio, and Vickers hardness of 1153.7 MPa, 25.4%, and 289.2 HV, respectively. These values indicated increases of 9.8%, 27.0%, and 4.9% over those of the untreated sample. These findings revealed that pulsed magnetic field treatment enhanced the strength and toughness of the material and preserved its high hardness. Overall, the high-pulsed magnetic field treatment emerged as a novel solid-state treatment method for HEAs, resulting in improved strength and toughness. This improvement can be attributed to the synergistic effects of various strengthening mechanisms, such as dislocation strengthening and fine-grain strengthening.