W. Fürbeth, B. Tigges, F. Feil, A. McSloy
Proc. EUROCORR 2012, Istanbul/TR, 2012
Combined chemical conversion and SiO2 nanoparticle coatings on AZ31 were prepared to compare their layer properties to pure conversion coatings and pure nano-particle coatings. It was shown that the addition of nanoparticles to an established conversion solution (Surtec 650) did not lead to a reduction of dispersion stability. Particle size and viscosity of the dispersions remain almost constant. Homogeneous coatings are formed for SiO2 contents of 6-8 wt-% and short immersion times. Salt spray tests show that combined coatings perform better than pure Surtec 650 coat-ings. This is further corroborated by first impedance spectroscopy investigations.