Cathodic electrocoat primers (cathodic e-coat) have been widely adopted by the automobile industry. One drawback to these coatings is that they display a tendency for formation of crater-like features when applied to zinc-rich surfaces under typical automotive application conditions.Our studies show that cratering susceptibility is an inherent property of zinc and that the craters result from localized dielectric breakdown of the e-coat film during deposition. Energy from the electric discharges displaces the e-coat at the discharge sites and locally cures the adjacent e-coat. During cure-baking, the locally cured e-coat does not re-flow to fill the voids created by the discharges, resulting in crater-like features in the cured e-coat film.
Mechanism of Cathodic Electrocoat Primer Cratering
Sae Technical Papers
SAE Automotive Corrosion and Prevention Conference and Exposition ; 1983
1983-12-05
Conference paper
English
Mechanism of Cathodic Electrocoat Primer Cratering
Automotive engineering | 1983
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