High temperature cyclic oxidation behavior of Y2O3-ZrO2 thermal barrier coatings irradiated by high-intensity pulsed ion beam

2009 ◽  
Vol 16 (1) ◽  
pp. 13-17
Author(s):  
Yi-qi Wang ◽  
Ming-kai Lei ◽  
A. M. Afsar ◽  
J. I. Song
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
High Intensity ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Ion Beam ◽  
Thermal Barrier ◽  
Barrier Coatings

Cyclic Oxidation Behavior of Thermal Barrier Coatings Irradiated by High-Intensity Pulsed Ion Beam

2008 ◽  
Vol 33-37 ◽  
pp. 1337-1344
Author(s):  
Yi Qi Wang ◽  
W.K. Joo ◽  
Chae Sil Kim ◽  
Jung I. Song
Keyword(s):  
Weight Gain ◽  
Thermal Barrier Coatings ◽  
High Intensity ◽  
Cyclic Oxidation ◽  
Ceramic Coating ◽  
Ion Beam ◽  
Thermal Barrier ◽  
Bonding Layer ◽  
Barrier Coatings ◽  
Columnar Grains

High-temperature oxidation resistance of 7 wt.％Y2O3-ZrO2 thermal barrier coatings (TBCs) irradiated by high-intensity pulsed ion beam (HIPIB) has been investigated in a cyclic oxidation condition at 1050 °C ×1 h. The ceramic coating of a tetragonal ZrO2 phase structure was prepared on GH33 superalloy substrates with a NiCoCrAlY bond coat by using electron-beam physical-vapor deposition (EB-PVD). The ceramic coating is composed of columnar grains forming dense clusters spacing with several-μm gaps among grain clusters. The characteristics of the columnar grains disappeared after HIPIB irradiation at the ion current densities of 100-200 A/cm2, and the irradiated surface presented a smoothed, densified feature after the remelting and ablation due to the HIPIB irradiation. The thickness of the densified layer is about 1 μm. After oxidation with 15 cycles at 1050 °C ×1 h, the oxidation kinetics curves of the as-deposited and irradiated TBCs showed a parabolic shape. The weight gain of original sample is about 0.8-0.9 mg/cm2, while the values of the HIPIB-irradiated TBCs decreased to some extent. The lowest weight gain is obtained for the irradiated TBCs at 200 A/cm2 with one shot, being 0.3-0.4 mg/cm2, and those at 100 A/cm2 have a medium weight gain of 0.6-0.7 mg/cm2. The cross-sectional morphologies of HIPIB-irradiated TBCs show less oxidation of the NiCoCrAlY bonding layer, with a thinner thermally grown oxide (TGO) layer. The morphology observation is consistent with the results of cyclic oxidation test. It is found that the inward diffusion of oxygen through TBCs can be significantly impeded by the densified top layer by the HIPIB irradiation, thus limiting the oxidation of the bonding layer, improving the overall oxidation resistance of the irradiated TBCs.

Microstructural Features of EB-PVD Thermal Barrier Coatings Irradiated by High-Intensity Pulsed Ion Beam

2008 ◽  
Vol 373-374 ◽  
pp. 300-303 ◽  
Author(s):  
C. Liu ◽  
X.G. Han ◽  
X.P. Zhu ◽  
M.K. Lei
Keyword(s):  
Electron Microscope ◽  
Thermal Barrier Coatings ◽  
High Intensity ◽  
Physical Vapor Deposition ◽  
Ion Beam ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
Barrier Coatings ◽  
Transmission Electron ◽  
Single Column

Thermal barrier coatings (TBCs) fabricated by electron-beam physical-vapor deposition (EB-PVD) were irradiated by high-intensity pulsed ion beam (HIPIB) at an ion current density of 100 A/cm2 with a shot number of 1-10. Microstructural features of the irradiated EB-PVD TBCs were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. All the HIPIB-irradiated EB-PVD TBC surfaces present smooth and densified features. The originated intercolumnar channels growing out to the top-coat surface and nanometer-scale gaps inside each single column were sealed after the remelting of TBC surface induced by HIPIB, resulting in formation of a continuous remelted layer about 1-2 μm in thickness. The dense remelted layer can work as a barrier against the heat-flow and corrosive gases, and gives the possibility of improving thermal conductivity and oxidation resistance of the HIPIB irradiated EB-PVD TBC.

Cyclic-Oxidation Behavior of Thermal-barrier Coatings Exposed to NaCl Vapor

2007 ◽  
Vol 69 (1-2) ◽  
pp. 119-130 ◽  
Author(s):  
Chungen Zhou ◽  
Yingxue Song ◽  
Changliang Wang ◽  
Huibin Xu
Keyword(s):  
Thermal Barrier Coatings ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Nacl Vapor

Thermal Cyclic Behaviour of Conventional YSZ and Mullite-YSZ Thermal Barrier Coatings

2020 ◽  
Vol 405 ◽  
pp. 417-422
Author(s):  
David Jech ◽  
Pavel Komarov ◽  
Michaela Remešová ◽  
Lucie Dyčková ◽  
Karel Slámečka ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Phase Stability ◽  
Bond Coat ◽  
Cyclic Oxidation ◽  
Thermally Grown Oxide ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Mullite Phase

Nowadays commonly used thermal barrier coatings (TBC) are based on yttria stabilized zirconia (YSZ). Addition of mullite phase into the YSZ coating can improve resulting high temperature properties. The contribution focuses on high temperature cyclic oxidation behaviour of two TBC systems with different top coats (TC) deposited by the means of atmospheric plasma spraying. The initial mullite-YSZ powder mixture consisted of 29 vol. % of mullite and 71 vol. % of YSZ. The conventional TBC system consisted of ~ 150 µm thick NiCoCrAlYHfSi bond coat (BC) and ~ 300 µm thick YSZ top coat. The experimental mullite-YSZ (MYSZ) TBC system consisted of ~ 150 µm thick NiCoCrAlYHfSi bond coat, ~ 100 µm thick YSZ interlayer and ~ 200 µm thick mullite-YSZ top coat. The experimental TBC proved higher lifetime, durability and phase stability and also lower grow rate of thermally grown oxide (TGO) compared to conventional TBC. Lifetime, phase stability and changes in the microstructure of TBCs after the furnace cyclic oxidation test were evaluated by the means of scanning electron microscopy equipped with EDX analyzer and X-ray diffraction techniques. Oxidation kinetics of TGO was calculated based on thickness determined utilizing digital image analysis.

Structure and Performance of YSZ Thermal Barrier Coatings Irradiated by High Intensity Pulsed Ion Beam

2012 ◽  
Vol 538-541 ◽  
pp. 2377-2381 ◽  
Author(s):  
Xian Xiu Mei ◽  
Yue Liu ◽  
Xue Ma ◽  
You Nian Wang
Keyword(s):  
Thermal Barrier Coatings ◽  
High Intensity ◽  
Ion Beam ◽  
Xrd Analysis ◽  
Isothermal Oxidation ◽  
Atmospheric Plasma ◽  
Cubic Phase ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Micro Cracks

The thermal barrier coatings (TBC) of the yttria-stabilized zirconia (YSZ) has been deposited by the atmospheric plasma spraying (APS),followed by the irradiation of high intensity pulsed ion beam (HIPIB) with the voltage of 250 KV and the ion current density of 300 A/cm2 and pulsed times of 2, 5, 10 and 20, respectively. The X-ray diffraction (XRD) analysis reveals that the coating is characterized by the tetragonal ZrO2 phase instead of the cubic phase and the original monoclinic phase after the irradiation. The scanning electron micros cope analysis demonstrates that the HIPIB treatment leads to a smooth TBC surface, but produces micro-cracks and round grain at the surface. This implies that the plasma erupts during the ion beam interaction with the coatings with poor thermal conductivity, and the micro-cracks were produced in the cooling process. The isothermal oxidation experiment performed at 1050°C in air and suggests that the oxidation resistance of the coating can be largely enhanced after HIPIB treatment.

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