Electromagnetic metamaterials sensor for structural integrity of zirconia doped on rare earth coating on stainless steels

Speaker:
Savin, Adriana; Institutul National de Cercetare-Dezvoltare pentru Fizica Tehnica; Romania

Authors:
Savin, A.; National Institute for Research and Development for Technical Physics; Romania
Craus, M.L.; National Institute for Research and Development for Technical Physics; Romania
Steigmann, R.; National Institute for Research and Development for Technical Physics; Romania
Turchenko, V.; Joint Institute for Nuclear Research; Russia
Novy, F.; University of Žilina; Slovac Republic
Grum, J.; University of Ljubljana; Slovenia

ID: ECNDT-0422-2018
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Thermal barrier coating (TBC) is used as thermal protective layer dedicated to metallic components in high temperature region, on engines and gas turbines, leading to high component reliability and operating temperature, resulting in higher efficiency and better environmental benefits. Zirconia doped with rare earths oxides is considered a good TBC material due of its low thermal conductivity, refractory, chemical inertness, and compatible thermal expansion coefficient with metallic support. The base material (substrate) is an AISI 316L stainless steel. The ceramic zirconia top-coating is nonconductive and nonmagnetic and therefore behaves like an air gap between the electromagnetic (EM) sensor and the conductive substrate and only creates a probe lift off effect for this method. The substrate AISI 316L stainless steel is nonmagnetic, when is formed only by an austenite type phase, with magnetic permeability equal to 1, allowing electromagnetic test.
The paper purpose is to emphasize the improvement of Zr coating-based ceramics properties as a function of addition of Y2O3 in the structure of the original ceramics. The structural investigations proposed in this paper cover destructive and nondestructive methods (EM, EA, SEM, X-ray, neutron diffraction ) offering the first indication of the variation of the phase composition and the structural parameters, micro-hardness measurements as well in order to analyze the structural properties of these materials with upmost importance in fields such as thermal protective layer dedicated to metallic components in high temperature region, on engines and gas turbines.