Doped Oxides for High-Temperature Luminescence and Lifetime Thermometry

Abstract

The measurement of high temperatures in oxides and oxide-based structures in practical applications often presents challenges including steep thermal gradients, the presence of flames or chemically aggressive environments, and the transparency or translucency of most oxides. For turbine engines, oxide coatings are of great commercial importance, and the rapid motion of parts prohibits contact thermometry. Luminescence thermometry offers a number of advantages for measuring temperature in such systems and has been the subject of ongoing study for many years. Recent work on rareearth-doped thermal barrier coatings, environmental barrier coatings, and related oxides has demonstrated the feasibility of luminescence thermometry to temperatures well in excess of 1000 • C. The luminescent properties of these materials and the analytical techniques used to extract reproducible temperature measurements from the measured luminescence are reviewed. 325 Annu. Rev. Mater. Res. 2009.39:325-359. Downloaded from www.annualreviews.org by University of Wisconsin -Madison on 09/25/12. For personal use only.

Nanophosphor Coatings: Technology and Applications, Opportunities and Challenges

“…The options here are almost unlimited: if a high sensitivity in the physiological range is required, one can use upconverting nanoparticles (Fischer et al, 2011). In the range of extreme temperatures, nanoparticles of refractory phosphors could probably be applied even above 1000°C because the emission of bulk thermographic phosphors such as YAG:Dy can be measured up to 1700°C (Chambers and Clarke, 2009). The resolution of nanothermometry is approaching the size of the single nanoparticle and allows the temperature inside the living cells to be measured (Vetrone et al, 2010).…”

Phosphor thermometry on a rotating flame holder for combustion applications

“…Phosphor thermometry has appeared to be an interesting trade-off for these applications. Being semi-invasive as it requires to add a thin coating of phosphor particles, this techniqueoften named laser-induced phosphorescence (LIP)-uses rare-earth-doped ceramic phosphors whose spectroscopic properties are highly sensitive to temperature (Allison and Gillies 1997;Khalid and Kontis 2008;Chambers and Clarke 2009). In practice, this technique can be either implemented in the temporal domain, by measuring the phosphorescence glowing after excitation (Knappe et al 2012), or in the spectral domain, by estimating a ratio of intensities (Feist et al 2002).…”

Evaluation of the in-depth temperature sensing performance of Eu- and Dy-doped YSZ in air plasma sprayed thermal barrier coatings

“…Consequently, accurate temperature measurement under engine operating conditions is of paramount importance if reliable life predictions are to be made and novel cooling schemes are to be designed [4]. The application of conventional contact-type temperature measurement is difficult or even impossible due to the inaccessibility and the high-speed motion of the engine components [5]. Similarly, the translucent nature of most ceramic TBCs poses problems for pyrometry when the TBC is under a temperature gradient since the thermal radiation sampled by the pyrometer originates from TBC at different depths and temperatures [1,5,6].…”

“…The application of conventional contact-type temperature measurement is difficult or even impossible due to the inaccessibility and the high-speed motion of the engine components [5]. Similarly, the translucent nature of most ceramic TBCs poses problems for pyrometry when the TBC is under a temperature gradient since the thermal radiation sampled by the pyrometer originates from TBC at different depths and temperatures [1,5,6]. An alternative method is thermal barrier sensor coatings technique, which was proposed by Feist et al [7] and has shown the ability to overcome these difficulties [8][9][10][11].…”