The corrosion resistance of FeSiBPNbCu bulk metallic glasses in sulphuric acid solutions

摘要

In this paper, the alloyingeffects ofminorCu on the relationship betweenmicrostructure and corrosion resistance of (Fe0.76Si0.09B0.1P0.05)(99-x)Nb1Cux (x=0, 0.25, 0.5, 0.75, 1) ferromagnetic bulk metallic glasses (BMGs) were investigated in details. The microstructure characterisation has revealed that the introduction of proper Cu elements leads to the presence of alpha-Fe clusters in the as-cast amorphous rods. In addition, alpha-Fe nanocrystals with a suitable size and volume fraction can accelerate the formation of the protective passive layers at nanocrystals/amorphous interfaces, and lead to the improvement of corrosion resistance. However, when the Cu content x exceeds 0.75, the corrosion resistance of the FeSiBPNbCu BMGs reduces significantly. All the results imply that the Cu content plays a key role in the characteristic size of alpha-Fe nanoparticles embedded in the glassy matrix, and there is a dependent correlation between the corrosion resistance and the microstructure.