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Thermal barrier coatings (TBCs) are widely used to protect high temperature structure parts against oxidation and corrosion. The failure mechanism study of TBCs is very important and the stress evolution is core content of failure mechanism research. In this work, a 8YSZ:Eu coating was produced via atmospheric plasma spraying (APS) method. Thermal cycling tests was carried out at 1300 ℃. The residual stress evolution of the coating was detected by a Eu3+ photoluminescence piezo-spectroscopy based on the relationship between stress and the peak position of 5D 0 →7F 2 transition of Eu3+ ions. The failure mechanism of the 8YSZ:Eu coating was also studied. The as-sprayed 8YSZ:Eu coating contains metastable t ´ -ZrO 2 and amorphous structure. The stress distribution is inhomogeneous with both compressive stress and tensile stress. After 1000 thermal cycles, the initial compressive stress changed to tensile stress due to the thermal expansion coefficients (TEC) mismatch and irreversible plastic deformation during thermal cycling. With thermal cycling going on, the compressive stress appeared again and the averaged tensile stress decreased due to the volume expansion caused by phase transformation of the t ´ -ZrO 2 to m-ZrO 2 and the formation of cracks. Formation of the thermally grown oxide (TGO), phase transformation, thermal expansion mismatch are factors for the coating failure. • A Eu3+ photoluminescence piezo-spectroscopy was used to measure the residual stress. • The residual stress distribution and evolution of the 8YSZ:Eu layer during thermal cycling was studied. • A 8YSZ:Eu coating was prepared by atmospheric plasma spraying and thermal cycling behavior was studied. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effect of aging on the luminescence properties from 8YSZ:Eu are studied. [•] The addition of Eu3+ in 8YSZ can improve the phase stability at high temperature. [•] The changes in the peak properties of 5D0 → 7F2 transition are analyzed. [Copyright &y& Elsevier]

Highlights: [•] A five-layer LZ7C3/8YSZ FG-TBCs has been prepared by atmospheric plasma spraying. [•] TECs of the five ceramic layers of the graded coating are gradually increased. [•] The failure mechanism of the graded coating has been analyzed. [ABSTRACT FROM AUTHOR]

Highlights: [•] DCL coating of LZ7C3/8YSZ prepared by APS shows promising performance at 1250±50°C. [•] A Eu3+-doped luminescence sublayer was used to indicate the spallation situation and damage degree. [•] Thermal cycling behavior and failure mechanism of DCL coating system were studied. [ABSTRACT FROM AUTHOR]

In the present study, 8YSZ:Eu 3+ powder was synthesized using co-precipitation route. The evolution of phase composition and fluorescence properties of 8YSZ:Eu 3+ powder have been assessed after being subjected to hydrothermal degradation for different times. Morphology and microstructure of the sintered powder were observed by transmission electron microscope (TEM) and scanning electron microscope (SEM). XRD, Raman spectra, photoluminescence (PL) spectra and the decay curve were used to evaluate the phase composition variation and fluorescence properties variation of the powder. The results showed that 8YSZ:Eu 3+ powder had a pure tetragonal phase structure. Under hydrothermal degradation conditions, due to the reaction of OH − and oxygen vacancy, the transformation of tetragonal to monoclinic occurred, furthermore the fluorescence properties of the powder were altered. [ABSTRACT FROM AUTHOR]

Highlights: [•] m-, t- and c- zirconia samples were prepared by controlling Y3+ doping concentration. [•] The fluorescence properties of m-, t- and c- zirconia samples were investigated. [•] The relationship between crystal structure and PL properties were further examined. [•] The PL properties of Eu3+ can be used to infer crystal structure of Eu3+-doped ZrO2. [Copyright &y& Elsevier]

Highlights: [•] Synthesis of TiB2–TiC–Al2O3/Al composite coatings on Mg alloy by RPS. [•] Microstructure and properties of the RPS coatings were characterized. [•] The coatings consist of TiB2, TiC, Al2O3 and/or excess Al without by-products. [•] The coatings display dense structure and good interfacial bonding with substrate. [•] The coatings provide good protection for the Mg alloy against wear and corrosion. [ABSTRACT FROM AUTHOR]