Corrosion behavior of bulk metallic glass Pr60Fe30−xTMxAl10 in NaCl aqueous solution

In this paper, Mn, Ni, Cu and Ti were selected as the partial substitution elements for Fe to produce Pr60Fe30−xTMxAl10 (TM = Mn, Ni, Cu, Ti; x = 0, 5 at.%) quaternary bulk metallic glasses (BMGs) by copper mold casting. The microstructure of samples was characterized by X-ray diffraction (XRD) and the effects of substitution elements on glass forming ability (GFA), electrochemical corrosion behavior in 3.5 wt.% NaCl solution were investigated by differential scanning calorimetry (DSC), potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The thermal parameters (e.g. Tx/Tl, γ, Gs, etc.) deduced from DSC indicated that all the samples possessed an amorphous phase and had a high GFA, the GFA of the samples ranks from high to low in the order: Pr60Fe25Mn5Al10 > Pr60Fe30Al10 > Pr60Fe25Ni5Al10 > Pr60Fe25Ti5Al10 > Pr60Fe25Cu5Al10 and the potentiodynamic polarization data analysis shows that the corrosion resistance ability ranks: Pr60Fe25Mn5Al10 < Pr60Fe30Al10 < Pr60Fe25Ni5Al10 < Pr60Fe25Cu5Al10 < Pr60Fe25Ti5Al10, which agrees well with that of the EIS data. In the case of the Pr-based BMGs, the GFA has not a correlation with the corrosion resistance, however the chemical composition is the dominating factor controlling the relative corrosion resistance.