SIMS study of a 55% AlZn alloy coating for corrosion protection of steel wire products

Abstract

Secondary ion mass spectrometry with a Cameca ion microscope was used to study the surface and in-depth composition of a 55 wt ' / ' Al-Zn coating on steel wire. Several surface contaminants of the coating (C, Na, Mg, F, C1, K, Ca, Mn and Fe) were identified and the spatial distribution of some of them and of the coating components Al, Si and Zn were obtained. The dendritic-interdendritic structure of the Al-Zn coating was observed using a secondary ion imaging facility. The distribution at the surface of the coating constituents Na and CI, C and A1 and Mn and Fe were strongly correlated. Quantitative analysis showed that the Mn and Fe surface concentrations were some hundreds and some thousand p.p.m. wt, respectively.