ELECTROCHEMICAL SENSORE FOR NONDESTRUCTIVE INSPECTION OF AD

Non-destructive inspection and evaluation (NDI, NDE) of adhesive joint integrity commonly requires separation of an interface or, in limited cases, a kissing unbond that has intimate contact, but no interfacial strength. DACCO SCI, Inc., and Michigan State University propose to adapt an in-situ corrosion sensor to detect the ingress of moisture into a bondline and the subsequent deterioration of joint properties. This sensor is based on the established laboratory technique of electrochemical impedance spectroscopy (EIS), but is suitable for field applications. It has been demonstrated to detect corrosion under paint coatings from the very early stages. Preliminary experiments show that it is also capable of detecting the initial stages of bond degradation in an adhesive joint. Use of this bondline sensor no monitor joint integrity will, provide advanced warning of potential degradation before it occurs. This then allows preventative maintenance to be performed prior to a decrease in structural strength or integrity. Resulting improvments in reliability, safety, and readiness will accrue.