Influence of Cold Rolling Process and Chemical Composition on the Mechanical Properties and Corrosion Behavior of Zr-Based Metallic Glasses

Abstract

Cold rolling (CR) with thickness reduction of 10%, 30%, and 50% was applied to Zr50Cu44Al6 and Zr49.5Cu44Al6Nb0.5 metallic glassy ribbon samples. The XRD patterns showed the amorphousness of all samples after casting and CR processes. The SEM images indicated the formation of multiple shear bands (SBs) owing to plastic deformation during CR. However, the addition of 0.5 at% Nb to the alloy changed the SBs’ density and spacing characteristics. The characterization of free volume changes caused by CR was carried out by measuring the density of Archimedes. The micro-hardness of samples was studied by investigating SBs and free volume during plastic deformation. Alloy softening occurred due to the formation of free volume during CR. X-ray photoelectron spectroscopy (XPS) confirmed the presence of oxides ZrO2, CuOx, and AlOx on the surface of the ribbons. The anodic polarization curves of the cast and R50 samples in solutions of NaCl and Na2SO4 (0.5 M) were obtained using potentiodynamic polarization measurements. Compared to CR ribbons, melt-spun ribbons after casting showed better corrosion resistance with lower anodic current densities in Na2SO4 solution.

Keywords

• Zr-based metallic glass
• amorphous material
• cold rolling
• shear band
• corrosion
• native surface oxide