Characterization of weathering degradation in aircraft polymeric coatings using NDE imaging techniques

This paper discusses the current progress in a study of nondestructive inspection methods for monitoring epoxy primer coating degradation under simulated weathering conditions. Characterization of the chemical changes in the coating will be conducted using attenuated total reflection (ATR) - Fourier transform infrared (FTIR) spectroscopy and IR microscopy. The nondestructive evaluation (NDE) methods used to monitor the physical degradation of the polymeric coating include: white light interference microscopy (WLIM), nanoindentation, and scanning acoustic microscopy (SAM). The microscopic images obtained using the NDE methods will be correlated with the measured physical and chemical changes. Artificial weathering of the coated samples was conducted using simulated sunlight exposure (Xenon are lamps), combined with heat and humidity.