CHARACTERIZATION OF ZINC PHOSPHATE COATINGS OBTAINED FROM MODIFIED BATHS

Zinc phosphate coatings obtained from phosphating baths modified with long-chain flotation surfactants, were characterized by scanning elect ron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy techniques. The results of these characterization studies were correl ated to the mechanism proposed to explain the influence of these addit ives on the nature and quality of the phosphate coatings obtained in t heir presence, as well as to explain the behaviour of these coatings i n aggressive environments. These studies indicate that the surfactant additives not only control the initial nucleation process but also par ticipate during the subsequent stages of coating deposition, and regul ate its growth.