Nanostructure of Materials and Corrosion Resistance

The application of nanotechnology in the field of corrosion protection of metals and alloys attracts the attention of researchers. Many of these applications require good understanding of the corrosion behavior of the materials as a function of microstructure. Significant prog‐ ress has been made in various aspects of synthesis of nano-scale materials. In addition, nanostructures promote selective oxidation, forming a protective oxide scale with superior adhesion to the substrate. Nanostructured materials of 1–100 nm are known for their out‐ standing mechanical and physical properties due to their extremely fine grain size and high grain boundary volume fraction [1]. They are important due to their unique properties that may lead to new and exciting applications [2]. Nanocomposite of polymer coating can effec‐ tively combine the benefits of organic polymers, such as elasticity and water resistance to that of advanced inorganic materials, such as hardness and permeability. The nanostruc‐ tured silica coating showed comparable or better performance than hexavalent chrome pas‐ sivation [3, 4]. Such behavior of nanostrucured materials, which relates to corrosion resistance, relies on materials microstructure. In fact, most properties of solids depend on the materials microstructure. The microstructure includes a number of parameters such as the chemical composition, the arrangement of the atoms (the atomic structure) and the size of a solid in one, two or three dimensions [5]. Comparable variations have been noted if the atomic structure of a solid deviates far from equilibrium or if its size is reduced to a few in‐ teratomic spacing in one, two or three dimensions. Nanoporous metals (NPMs) made by dealloying represent a class of functional materials with the unique structural properties of mechanical rigidity, electrical conductivity, and high corrosion resistance [6]. It is stated by Weissmüller et. al, that the prospect of using alloy corrosion as a means of making nanoma‐ terials for fundamental studies and functional applications has led to a revived interest in the process. The quite distinct mechanical properties of nanoporous metals are one of the fo‐ cus points of this interest, as relevant studies probe the deformation behavior of crystals at