Galvanostatic testing of coated aluminum alloy 7075‐T6 galvanic assemblies: Effects of coating systems and environmental factors

Abstract

A galvanostatic test panel design consisting of a coated and scribed 7075‐T6 Al alloy as a working electrode and an uncoated through‐hole 316 stainless‐steel fastener as a counter electrode has been used to accelerate galvanic corrosion and compare various primer coatings and pretreatments and different impressed passed currents in an ASTM G85‐A2 environment. The relative humidity, chloride concentration, and impressed current magnitude were changed to investigate their effects on galvanic corrosion. During the chamber exposure, the electrochemical measurements showed fluctuations in the measured current and potential. Various corrosion morphologies, depths, and volume loss were recorded for panels with different coating systems. Electrochemical measurements, optical profilometry, and photography were used to characterize and measure the corrosion performance of different coating systems. Also, electrochemical impedance spectrometry was used to compare the corrosion resistance and porosity of different coating systems.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 08, 2022
Source ID
10.1002/maco.202213049

Entities

People

  • Gerald S. Frankel
  • Mahdi Jokar

Organizations

  • Office of Naval Research
  • Ohio State University

Tags

Fields of Study

  • Materials science

Readers

  • Aerospace Test and Evaluation
  • Materials Science and Engineering.