Phosphor thermometry in an electron beam physical vapour deposition produced thermal barrier coating doped with dysprosium

Abstract

In the paper the production and testing of a prototype smart thermal barrier coating (TBC) consisting of yttria-stabilized zirconia (YSZ) doped with dysprosium is described. The coating was produced using the electron beam physical vapour deposition (EBPVD) technique and consisted of a 180 ím thick layer of YSZ doped with 10 per cent dysprosium layed down on an aluminized C263 substrate. The thermoluminescent properties of the coating were investigated with the sample placed in a temperature-controlled furnace and illuminated with UV light from a pulsed laser. Using an intensity ratio technique comparing emission at 455, 482 and 493 nm (the preferred ratio being 455 nm=482 nm), the coating was shown to be suitable for temperature measurement from 534 K to at least 950 K with an uncertainty of better than ±2.6 per cent. The research therefore demonstrates the possibility of producing smart TBCs with both thermal insulating and temperature sensing properties using a production coating technique. Further work is now required to optimize the concentration of the dysprosium dopant for maximum dynamic range and measurement precision and to investigate the thermomechanical properties of the coating.