PZT based smart corrosion coupon using electromechanical impedance

Corrosion induced material loss in metallic structures is a widespread and urgent problem across multiple industries. In this paper, a novel corrosion monitoring method is proposed based on the lead zirconate titanate (PZT) based smart corrosion coupon (SCC) using electromechanical impedance (EMI). The basic idea of the corrosion monitoring method is that the corrosion induced thickness loss of the SCC will leads to the variation in the EMI signatures. The SCC was fabricated by bonding a PZT patch onto a corrosion coupon. The EMI signatures of the SCC under different corrosion amount were acquired and analyzed. Results showed that the peaks in the conductance signatures present a leftward shift and the peak frequencies decrease linearly with increase of the corrosion amount. To obtain more insight into SCC electromechanical system, the finite element analysis were also performed to study the EMI response and modal characteristics. The simulation results agreed well with experimental results. And it was found that the coupled bending modes are very sensitive to the corrosion induced thickness loss. The proposed smart corrosion coupon is cost effective, capable of determining corrosion amount quantitatively, and has promising application potential. (C) 2019 Elsevier Ltd. All rights reserved.