S18  Processos Mecânico-Metalúrgicos
 
 Title:
A TECHNIQUE FOR ELECTROCHEMISTRY ANALYSIS OF POROSITY OF COATINGS ON METALLIC SURFACES
 
Summary :
THE WORK TO BE PRESENTED REFERS TO THE APPLICATION OF ANODIC VOLTAMETRIC DISSOLUTION TECHNIQUE IN THE ANALYSIS OF THE POROSITY OF COATINGS WITH RELATIONSHIP TO PORES AND CRACKS. THE COATINGS ANALYZED IN THIS WORK ARE METALLIC AND OBTAINED BY ELECTROCHEMICAL PROCESSES ON METALLIC SUBSTRATE. HOWEVER, THE TECHNIQUE USED IS ALSO SUITABLE FOR POROSITY ANALYSIS OF METALLIC COATINGS OBTAINED BY OTHER PROCESSES, AS WELL AS FOR CERAMIC COATINGS, SINCE ON A METALLIC SUBSTRATE. THE APPLIED TECHNIQUE CONSISTS OF THE COMPARISON AMONG THE CHARGE DENSITIES INVOLVED IN THE PASSIVATION PROCESS OF THE SUBSTRATE WITHOUT COATING, AND COVERED WITH A WELL-KNOW CHARGE DENSITY. THE PASSIVATION SOLUTION WAS SELECTED TO MAINTAIN THE COATING INACTIVE IN THE REGION OF POTENTIALS IN WHERE IT HAPPENS, THUS PRESERVING THE INTEGRITY OF THE COATING. THE OBTAINED RESULTS, FOR NICKEL COATING ON COPPER, INDICATE AN EXPONENTIAL DECLINE OF THE POROSITY WITH THE THICKNESS OF THE COATING AND THE DECLINE RATE IS AN INDICATIVE OF THE LEVEL OF TENSIONS OR DEFECTS IN THE COATING. KEYWORDS: POROSITY MEASUREMENT, METALLIC COATINGS, THIN FILMS, PASSIVATION.  
 
Author :
Maul, Alexandre Michel
Ponte, Haroldo Araújo
 
 
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