SKPFM and SEM study of the deposition mechanism of Zr/Ti based pre-treatment on AA6016 aluminum alloy

The formation of the conversion layer progressively reduces the Volta potential difference between intermetallics and matrix. This potential difference is completely eliminated for relatively long immersion times. This is associated to an improvement of the corrosion behaviour of AA6016, as shown by potentiodynamic polarization curves. Besides, the deposited conversion layer improves the adhesion of an acrylic paint on the alloy.