Change in Electrochemical Impedance Spectrum of Al/CFRP Adhesive Lap Joint by High Temperature, High Humidity-Cold Cycle test

Abstract

Weight reduction of automobiles is an effective way to reduce carbon dioxide emissions. To reduce the weight, the adhesion joints of light materials are expected to be widely used. However, the deterioration evaluation for the adhesion joints exposed to corrosive environments such as the salt-damaged area is carried out by destructive evaluation methods like a tensile test.

In this study, to develop a non-destructive method to detect the deterioration of the Al/CFRP lap joints by adhesive, we investigated the change in the electrical characteristics of the joints before and after corrosion tests by electrochemical impedance spectroscopy. It was found that the impedance and the frequency dependence of the dielectric loss tangent of the joints were changed by corrosion test.