Open Access
ARTICLE
Experiments on the Testing Sensitivity for Microstructure Evolutions of Coatings by Electro-Mechanical Impedance Method in kHz and MHz Frequencies
Ji-Cheng Li1, Li Lin1,2, Di Wu1, Xi-Meng Li1, Ming-Kai Lei3
1 NDT & E Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 1 16024, China
2 Corresponding author: Li LIN, Dalian University of Technology, Dalian 116024, P.R. China, Tel:
0086-0411-84707117, E-mail: linli@dlut.edu.cn
3 Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University
of Technology, Dalian 116024, China
Structural Longevity 2010, 4(2), 85-93. https://doi.org/10.3970/sl.2010.004.085
Abstract
Two kinds of plasma sprayed Cr
2O
3 coatings are characterized by
electro-mechanical impedance (EMI) method with PZT patch in kHz and MHz frequencies. Comparing frequency shift of impedance peaks f and root mean square
deviation (RMSD) of PZT electric impedance signatures, the influence of frequency
on the testing sensitivity is investigated in some frequency bands among 10-238
kHz and 5.45-6.33 MHz. The results show that in the kHz frequency range, the frequency shifts f increase with testing frequency and the RMSD values first increase
and then decrease. The latter may be attributed to the decreasing of peak number
and the decline of impedance magnitude. In MHz frequency range, the frequency
shifts f become more significant, and a prominent frequency shift of 206.1 kHz is
observed near 6 MHz. The RMSD values are also much larger than that in kHz
frequency range.
Keywords
Cite This Article
Li, J., Lin, L., Wu, D., Li, X., Lei, M. (2010). Experiments on the Testing Sensitivity for Microstructure Evolutions of Coatings by Electro-Mechanical Impedance Method in kHz and MHz Frequencies.
Structural Longevity, 4(2), 85–93.