Non-Uniform Corrosion Governed by Metallurgy

For both reaction paths, as atoms leave from kink sites, the mono-atomic steps are displaced on the surface. If the number of kink sites on a step does not depend on the distance between steps, the dissolution current density is equal to [2]  

According to (7.22), the rate of anodic dissolution at a given potential increases with the density of atomic steps. For slightly misoriented planes with respect to a low index plane, it is therefore expected to vary with the angle of misorientation. 

By rapid solidification, it is possible to produce alloys that show an X-ray amorphous structure. Typically, these alloys contain a large fraction of non-metallic elements, such as boron or phosphorus, which slow down crystallization. Atoms in amorphous alloys are less densely packed than in crystalline alloys. Furthermore, amorphous structures are thermodynamically unstable. Both factors should induce a 

In metallography, differences in electrochemical properties of alloy phases are commonly used to visualize the microstructure of multi-phase alloys. The strongest selectivity is observed for conditions (electrolyte, potential) where one phase is active and the other passive. 

Polarization behavior of binary single-phase alloys 

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