A comparative study of electrochemical properties of metallic glasses and weld overlay coatings

The overlay coatings were corrosion tested in a 3% aqueous NaCl solution. The metallic glasses Ni60Nb20Zr20 coating plasma sprayed at 250 A arc current and the 45–50 mm spraying distance revealed the outstanding corrosion resistance and outperformed pad welded coatings. For all sprayed metallic glass coatings, the microhardness increased with the rising arc current. The corrosion resistance of Zr55Cu30Al10Ni5 sprayed deposits depends on their porosity and phase composition. The Ni- and Co-based hardfacings offer high corrosion resistance compared with the Fe-based ones. The corrosion resistance of Fe-based hardfacings is reduced by cracks and inclusions present in the coatings.