Effect of crystal orientation on the corrosion behavior of Mo3Si single crystals in 0.5 M H2SO4

The corrosion behavior of Mo3Si single crystals with crystallographic orientations 〈100〉, 〈110〉 and 〈111〉 in 0.5 M H2SO4 was analyzed using potentiodynamic polarization curves, electrochemical impedance spectrosopy, and electrochemical noise measurement. The corrosion behavior was different for each crystal orientation. The plane most susceptible to both uniform and localized types of corrosion was the (111) plane; the (110) plane exhibited the lowest susceptibility to uniform corrosion; and the (100) plane was the least susceptible to localized corrosion. These results were explained by differences in surface energy and the number of atoms per unit area.