Structural Nanocrystalline Materials: Corrosion of structural nanomaterials

Introduction Corrosion, degradation, and weathering of advanced materials are problems for which mankind has yet to find a proper solution. From the world's ancient man-made and natural monoliths to today's most modern buildings, bridges, and transportation facilities, the longevities of useful structures are closely regulated by the environment where they are located. Having little control over these aggressive environments, we must carefully select materials that have properties best suited for the conditions to which they are exposed. Even after 100 years of industrial revolution and the development of advanced materials, testing and monitoring procedures, we wonder if our knowledge of today's structural materials and their interactions in the current environment is sufficient to produce long-lasting structures that will benefit society. For example, the total cost of corrosion and corrosion-related issues in the USA alone is quite significant, amounting to 6% GDP or $500 billion per year (Koch et al. , 2002). This cost is distributed over direct costs on materials and structures and indirect costs on loss of productivity. About 90% of the corrosion cost is within iron-based materials. The annual direct cost of corrosion of highway bridges is estimated to be $8.3 billion, of which $3.8 billion is for bridge replacement, and $4 billion is for maintenance. It is estimated that indirect costs to the user due to traffic delays and lost productivity are about $38 billion annually. For more details, see the 2001 report by CC Technologies Laboratories, Inc., FWHA (2001).