Electrochemical Impedance Spectroscopy Analysis of Failure of Aircraft Surface Coating

Adopt accelerate circulation corrosion test methods which include impact test, salt spray test, ultraviolet illumination test and humid heat test to analysis the characteristics of electrochemical impedance spectroscopy (EIS) on different accelerate circulation time. The EIS of coating increased in the middle and late stages, and new time constants took place, which could be related to resolving of the chemical conversion film and corrosion of the aluminum on the activation zone. The water absorbing capacity of coating were calculated and found increasing at first and then decreasing with increasing of accelerated circulation time, the water absorption rate finally stabilized at about 5%.