Influence of metalloid element B on the microstructure and performances of novel FeCoNiVB high-entropy amorphous alloys

The influence of metalloid element B content on the microstructure, microhardness, thermal stability and anti-corrosion properties of (Fe_1/4Co_1/4Ni_1/4V_1/4)_100-xB_x (x = 16 ∼ 32 at.%) high-entropy amorphous alloys was studied systematacially. Results showed that the investigated alloy ribbons owned fully glassy nature. The average microhardness and crystallization onset temperature of these glassy ribbons were over 958 HV_0.2 and 757 K, respectively. The self-corrosion potentials of samples were −0.541 ∼ −0.484 V and the most positive potential could reach −0.484 V for the Fe₂₀Co₂₀Ni₂₀V₂₀B₂₀ alloy ribbons. Besides, this equiatomic specimen also owned the smallest corrosion current density of 5.87 × 10⁻⁶ A/cm² and the largest polarization resistance of 9635.7 Ω·cm². The experimental characterization analysis of alloy ribbons’ immersion tests further proved the credibility of measurement results. Therefore, it is indicated that the equiatomic FeCoNiVB high-entropy amorphous alloy possesses the best corrosion resistance in 3.5 wt% NaCl solution among studied samples and this alloy can be also viewed as a potential functional protective material combined with the anti-corrosion performance, wear resistance and thermal stability.