Study on corrosion behavior of continuous bulk metallic glass-coated steel wire composite

Zr41.2Ti13.8Cu12.5Ni10Be22.5 (atomic percent) (Vit1) Bulk metallic glass (BMG)-coated steel wire composite was produced by using continuous process. The existence of amorphous structure in the BMG coating was proved by differential scanning calorimeter (DSC) measurement and transmission electron microscope (TEM). The corrosion behaviors of the bare steel wire and the wire composite in 3.5 wt% NaCl solution corrosive media were investigated by immersion tests and electrochemical polarization measurements at room temperature. Scanning electron microscopy (SEM) was utilized to examine morphology of the corroded surface. By comparing the corrosion behaviors of the wire composite and the bare steel wire as well as the Vit1 BMGs reported in the literatures, the results of the present investigation reveal (1) it is important to choose sound technical parameters such as processing temperature to avoid the crystallization for the BMG coating of steel wire (2) the Vit1 BMG-coated steel wire composite has better corrosion resistance than the bare steel wire from perspective of either mass loss or polarization behavior (3) strong protective layers grow on the surface of the coated steel wire by anodization, of which the barrier effect to initiate pitting is slightly lower than that of the monolithic Vit1 BMG, but the general polarization behavior is quite similar to that of the monolithic Vit1 BMG.