Activation of galvanized steel surfaces before zinc phosphating — XPS and GDOES investigations

The effect of activation in the zinc phosphating has been studied phenomenologically by SEM and AFM. Kinetic investigations show that the activation plays an important role for the phosphating reaction. The activations underlie coagulation and sedimentation due to their colloidal character which again affect the reaction kinetics of phosphating. The adsorption of the titanium phosphate colloids was analyzed by XPS and GDOES. Whereas ESCA is not able to detect the adsorbed titanium phosphate particles using titanium as a central element, it is possible to identify it with GDOES.