Microstructure regulation and internal friction behavior of Fe₄₅Mn₂₀Cr₁₅Co₂₀ duplex high-entropy damping alloy

Damping alloys not only have the physical property of converting mechanical vibration energy into heat energy and dissipating it but also have good mechanical properties, corrosion resistance, structural stability, and so on. In this paper, a Fe45Mn20Cr15Co20 high-entropy alloy was prepared by vacuum arc melting, and the effects of annealing temperature on the evolution of its structure and internal friction behavior were investigated in depth. The results show that the annealing treatment improves the alloy's damping performance significantly. The best damping performance was obtained after annealing at 1000 degrees C: Q-1max= 0.0729, an increase of 22.5% compared with the as-cast state. Combining mechanical and damping properties, the alloy is annealed at 1000 degrees C to obtain the best combined strength-damping properties. Thus, the design requirement of structural-functional integration is achieved. In addition, the alloy still maintains the two-phase structure of gamma austenite and epsilon martensite after annealing treatment, and the content of epsilon martensite phase increases gradually with the increase of annealing temperature. The alloys formed a regular arrangement of chevrons and annealed twins when annealed at 1000 degrees C. The magnetic properties of the alloys gradually increase with the annealing temperature. The tensile strength of the annealed alloy tends to increase and then decrease with the increase of annealing temperature and reaches a peak (Rm = 780.8 MPa) at 1000 degrees C. This paper provides a reference of experimental data for realizing structural-functional integration of high entropy damping alloys.