Non-destructive surface analysis applied to atmospheric corrosion of tin

Tin samples have been exposed in industrial, rural and urban outdoor atmospheres. Corroded surfaces were studied with Fourier transform infrared reflection absorption spectroscopy (FTIRAS), x-ray diffraction (XRD), SEM, energy-dispersive spectroscopy (EDS) analysis and Mossbauer spectroscopy. Corrosion is continuous and heterogeneous during the first 10 months of exposure, and the corrosion products seem mainly insoluble and non-protective. Corrosion rate differs between each site of exposure, increasing from urban to rural area. Analyses performed reveal that the corrosion layers are mainly composed of poorly crystallized and hydrated stannic oxide SnO2.chiH(2)O. Lower proportions of Sn(II) and Sn(IV) corrosion products are also identified as carbonates, sulphates and chlorides compounds. The FTIRAS and Mossbauer spectroscopy analyses remain the most adaptable to perform the characterization of tin corrosion products. They give reliable information about the chemical species, the valence state of tin nuclei and the evolution of the corrosion layer with time. Copyright (C) 2002 John Wiley Sons, Ltd.