Effect of annealing on the microstructure, microhardness, and corrosion resistance of Ni62Nb33Zr5 metallic glass and its composites

Abstract The Ni62Nb33Zr5 metallic glass ribbon and its composites have been synthesized by the melt spinning method and proper annealing treatment. The effect of annealing treatment on the microstructural evolution, microhardness, and corrosion resistance in the 6 M HCl solution for the as-spun Ni62Nb33Zr5 metallic glass ribbon has been investigated. The results show that a small quantity of Ni phase firstly precipitates from amorphous matrix at the initial annealing stage, and final annealing products consist of the mixtures of the Ni, Nb oxides, ζ-NbNi4 phases, and some unknown phases with face-centered cubic structure. The as-spun specimen possesses the highest HV value of 580, which decreases approximately 45.3% to 317 of the as-annealed Ni62Nb33Zr5 metallic glass composite at 900 K. The electrochemical corrosion results show that corrosion potential values increase approximately 25.5% from − 0.47 V of the as-spun alloy to − 0.35 V of the as-annealed composite at 900 K and passive region increases about 1.1%. Combined with the corrosion morphologies, it presents that the precipitation of an appropriate amount of Nb oxides from amorphous matrix is beneficial to improve the corrosion resistance in the HCl solution for the 900 K as-annealed Ni62Nb33Zr5 composite.