No abstract

This paper presents the results obtained at 3 Antarctic test sites participating in the "Ibero-American Map of Atmospheric Corrosiveness" (MICAT), a project on atmospheric corrosion carried out during the period 1988-1994 at some 70 sites distributed across 12 countries of the Latin-American region, Spain and Portugal. The three Antarctic sites are located near the coastline. The singular climatic characteristics of Antarctic regions are related with the purity of the air, the absence of rainfall and the formation of ice on the metallic surface during an important part of the exposure time. However electrochemical activity is possible below ice layers. This situation affects the structure and morphology of corrosion product films and the resulting corrosion rates of metallic surfaces.

Comparison of early-and late-growth crystal morphologies of several water-soluble ionic materials suggests that early rapid growth is accompanied by a speci®c type of morphological distortion. This distortion, involving a change in the relative growth rate of just one growth direction, is consistent with our previously proposed mechanism for the transition from normal, polyhedral crystal growth to dendritic growth. Interpretation of this morphological distortion was aided by morphology prediction methods based on computed attachment energies.

No abstract

No abstract