Electrochemical and Structural Characterization of Nickel based Alloys Oxides

The electrochemical and structural characterization of thermally grown oxides formed on nickel based alloys (type Inconel 600 and 690) at 350 °C and during different time was performed by impedance measurements and near field microscopy combining atomic force microscopy (AFM) and scanning Kelvin probe force microscopy (SKPFM). The impedance results allow discussing the influence of the oxidation time on the capacitance and the resistance of the oxide films. The results obtained by near field microscopy technique show that the film formed during low oxidation time has a small grain size and also a small surface roughness. The values of grain sizes determined in both cases along x- and y-axis are practically the same indicating a spherical shape of oxide grains and are slightly different between oxides formed on type inconel 600 and 690.