Relation between quenching wheel speed and microstructure, thermal stability and corrosion resistance of quinary Al-Ni-Y-Co-Si high entropy metallic glass ribbons prepared by melt spinning

Abstract

To probe the relation between the wheel speed of a single copper roller and the microstructure and performance of high-entropy metallic glasses, in the current study, the microstructure, thermal stability and anti-corrosion properties of quinary Al-Ni-Y-Co-Si high-entropy metallic glass ribbons rapidly solidified by the melt-spinning method with various quenching wheel speeds were investigated by electrochemical impedance spectroscopy, potentiodynamic polarization measurements, thermal analysis and microstructural characterization. The experimental results show that all investigated alloy ribbons present an amorphous nature, but the wheel speed has little influence on the thermal stability of the measured specimens. With increasing wheel speed, the Vickers microhardness of alloy ribbons in the as-received state has a decreasing trend. After annealing at 773 K for 5 min, the XRD patterns of the heat-treated sample exhibit diffraction peaks of the α-Al, Al3Y, Ni74Si26, YCo3 and NiY intermetallic phases. From the electrochemical test, the alloy ribbons fabricated with a wheel speed of 2000 rpm exhibit both the lowest passive current density (3.24 × 10−6 A/cm2) and self-corrosion current density (0.84 × 10−6 A/cm2), indicating the lowest actual corrosion rate and the best corrosion resistance in 3.5 wt.% NaCl solution among the five kinds of alloy ribbons.