Accession Number:

ADA167281

Title:

Lifetime Prediction of Organic Coating/Metal Systems

Descriptive Note:

Final rept. 1 Jul 1979-31 Oct 1985

Corporate Author:

ROCKWELL INTERNATIONAL CORP THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s):

Report Date:

1986-04-01

Pagination or Media Count:

97.0

Abstract:

A lifetime prediction model has been developed for polymer coating metal systems. The elements of the model fall into the category of system variables that describe the surface of the substrate, the coating or the environment, or the category of processes that determine the degradation of the coated metal. These processes include formation of defects in the coating and at the metalcoating interface, transport of corrosive species to the metal, loss of adhesion, corrosion and failure. The casual relationship between system variables and processes has been discussed. The lifetime prediction model is based on a series of experimental studies which have been performed during the course of this project. A number of new techniques have been developed which can be used to determine the properties of the coatingmetal compound and its changes during interaction with corrosive environments. Electrochemical impedance spectroscopy EIS has been found to be very valuable in providing information concerning the coating and the metal surface and degradation of the coatings as corrosion proceeds. An acoustic pulse technique has been used to detect areas of delamination and corrosion. Acoustic emission from coated steel during straining of the sample has provided characteristic fingerprints for surface and coating properties and has demonstrated the importance of the mechanical properties of the coating. Keywords Anodizing Polyurethane coating Copper Zinc Electrodes Delamination Cathodic protection Pigments Sodium chloride Exposure.

Subject Categories:

  • Coatings, Colorants and Finishes
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE