| 1. |
- Talic, Belma, et al.
(författare)
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Correlating Oxygen Electrode Degradation to Cr Vaporization from Metallic Interconnects in Solid Oxide Cell Stacks
- 2023
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Ingår i: Journal of the Electrochemical Society. - 1945-7111 .- 0013-4651. ; 170:12
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Tidskriftsartikel (refereegranskat)abstract
- Symmetrical cells consisting of La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) oxygen electrodes screen printed on both sides of a Ce0.9Gd0.1O2-δ (CGO) electrolyte were tested at 800 °C while being held close to a piece of Crofer 22 APU alloy. The alloy was either just pre-oxidized or coated with MnCo2O4 and heat treated prior to the exposure test to elucidate the effects of different Cr vaporization rates. Degradation of the symmetrical cells was monitored by electrochemical impedance spectroscopy, and TOF-SIMS, SEM and EDX analysis were used to examine Cr deposition on the electrodes after the exposure. The results show that the degradation rate of the symmetrical cell is directly proportional to the concentration of gaseous Cr(VI)-species, which had been assessed in a previous experiment. The Cr vaporization rate from Crofer 22 APU with a dense MnCo2O4 coating was measured in moisturized air up with up to 40% H2O and found to be invariant with respect to the steam activity. The degradation rate of symmetrical cells was accelerated by humidity in the air, but, noteworthy, this was found also in the absence of a Cr source.
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| 2. |
- Yangui, Aymen, 1987, et al.
(författare)
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Phosphor Thermometry of Alumina-Forming High-Temperature Alloys Using Luminescent Rare-Earth Ions in YAG: Proof of Concept Using a Dispersion of Ce 3+ -Doped YAG Particles in a FeCrAl Alloy
- 2023
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Ingår i: ECS Journal of Solid State Science and Technology. - : The Electrochemical Society. - 2162-8777 .- 2162-8769. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Most high-temperature processes require monitoring and controlling temperature, preferably with high precision and good lateral resolution. Here we evaluate the use of the technique commonly known as phosphor thermometry, which exploits the temperature dependent photoluminescence from an inorganic phosphor, for the determination of the temperature of a composite material consisting of the metallic alloy FeCrAl dispersed with phosphor particles of yttrium aluminum garnet (Y3Al5O12, YAG) doped with a small amount of luminescent Ce3+ ions (YAG:Ce3+). The results show that with some optimization and by changing the dopant ion, YAG based phosphor particles offer a unique opportunity to measure the surface temperature of metal alloys with high precision and high lateral resolution, all the way up to the maximum working temperature of alumina-forming high temperature alloys at ca. 1300 °C.
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