Terahertz NDE for Under Paint Corrosion Detection and Evaluation

Abstract

ABSTRACT.Corrosion under paint is not visible until it has caused paint to blister, crack, or chip. If corrosion is allowed to continue then structural problems may develop. Identifying corrosion before it becomes visible would minimize repairs and costs and potential structural problems. Terahertz NDE imaging under paint for corrosion is being examined as a method to inspect for corrosion by examining the terahertz response to paint thickness and to surface roughness.

Detecting surface features on conducting specimens through an insulation layer using a capacitive imaging technique

“…Thermography has the ability to detect hidden corrosion [4,5]. Microwave [6] and TeraHertz [7] techniques have been investigated for the detection of corrosion under paint. Radiography techniques can provide thickness measurement and corrosion monitoring in metallic components [8].…”

Terahertz and Cultural Heritage Science: Examination of Art and Archaeology

“…There are other promising applications where THz has been tested even if less frequently. There is an increasing interest regarding THz application to detect and measure corrosion under paint for industrial applications [93][94][95][96]. This research could develop new THz methods for conservation of painted metal historical objects, such as furniture and sculptures.…”

Terahertz pulse imaging in archaeology

“…This particular application for TPIS is dependent on the ability of THz waves to distinguish dielectric corrosion products from their metallic source material by their transmissivity and reflectivity. Previous work has been done to find defects beneath the coating on metal surfaces [18,19], however not much THz research has been conducted to study the specific corrosion layers themselves. THz pulses have the potential to spectroscopically identify and spatially distinguish each layer.…”