Corrosion behavior of sputter-deposited W-Mo alloys in NaOH solutions

Abstract

The corrosion behavior of the sputter-deposited nanocrystalline WMo alloys is studied after immersion for 24-29 h in different concentrations

of NaOH solutions at 25 o C, open to air by using corrosion tests and open circuit potential measurements. Molybdenum metal acts synergistically with tungsten in enhancing the corrosion resistance of the sputter-deposited W-Mo alloys so as to show the lower corrosion rates than those of alloyconstituting elements (that

is, tungsten and molybdenum) after immersion for 24-29 h in NaOH solutions. In general, the open circuit potentials of all the examined W-Mo alloys are shifted to the more positive (noble) direction with increasing the molybdenum content in the alloys. The stability of the spontaneous passive films of the binary W-Mo alloys is decreased with increasing the concentrations of NaOH solutions. However, the corrosion rates of all the examined W-Mo alloys are almost independent of concentrations of NaOH solutions (that is, 0.01 M, 0.1 M and 1 M NaOH).