The corrosion behavior of porous Ni3Al intermetallic materials in strong alkali solution

Porous Ni3Al alloys was prepared by cold pressing and reactive synthesis of Ni and Al elemental powders via the Kirkendall effect. Corrosion behavior of porous Ni3Al alloys was investigated by electrochemical tests and weight change measurements. Polarization resistance indicated that porous Ni3Al had more positive free corrosion potential and lower corrosion current than porous Ni and porous Ti and exhibited a wider passive region. The immersion test revealed that after 2000 h immersion, the weight change and pore structure of porous Ni3Al stayed stable in KOH solution. The influence of temperature on corrosion behavior and corrosion mechanism of porous Ni3Al were also discussed. (C) 2011 Elsevier Ltd. All rights reserved