scholarly journals Microstructure Modification of CGDS and HVOF Sprayed CoNiCrAlY Bond Coat Remelted by Electron Beam

2016 ◽  
Vol 12 ◽  
pp. 89-94 ◽  
Author(s):  
Petra Gavendová ◽  
Jan Čížek ◽  
Jan Čupera ◽  
Makoto Hasegawa ◽  
Ivo Dlouhý
Keyword(s):  
Electron Beam ◽  
Bond Coat ◽  
Microstructure Modification

Delamination toughness of electron beam physical vapor deposition (EB-PVD) Y2O3–ZrO2 thermal barrier coatings by the pushout method: Effect of thermal cycling temperature

2008 ◽  
Vol 23 (9) ◽  
pp. 2382-2392 ◽  
Author(s):  
M. Tanaka ◽  
Y.F. Liu ◽  
S.S. Kim ◽  
Y. Kagawa
Keyword(s):  
Electron Beam ◽  
Thermal Cycling ◽  
Bond Coat ◽  
Physical Vapor Deposition ◽  
Thermally Grown Oxide ◽  
Test Method ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Delamination Toughness ◽  
Cycling Temperature

A pushout test method was used to quantify effect of thermal cycling temperatures on the delamination toughness of an electron beam physical vapor deposited thermal barrier coating (EB-PVD TBC). The delamination toughness, Γi, was related to the maximum thermal cycling temperature, Th, equal to 1000, 1025, 1050, and 1100 °C. The measured delamination toughness varied from 9 to 95 J/m2. At Th = 1000 °C, Γi attained a maximum value, larger than that of the as-deposited sample and decreasing with increased Th. During the thermal cycling tests, the thermally grown oxide (TGO) was formed between the TBC and the bond coat deposited onto the superalloy substrate. Inside the TGO layer, mixture of Al2O3 and ZrO2 oxides was observed close to the TBC side with nearly pure Al2O3 phases close to the bond-coat side. During the pushout test, delamination occurred at the interface of the mixture and pure Al2O3 layer with an exception for Th = 1100 °C specimens where delamination also occurred at the interface between the TGO and bond-coat layers. The effect of thermal cycling temperatures on the delamination toughness is discussed in terms of the microstructural change and delamination behavior.

HOT-CORROSION BEHAVIOR OF THERMAL BARRIER COATED DZ125 SUPERALLOY EXPOSED TO ATOMIZED SEAWATER AND KEROSENE

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3155-3160
Author(s):  
ZHIMING BAI ◽  
LE ZHOU ◽  
TIANQUAN LIANG ◽  
HONGBO GUO ◽  
SHENGKAI GONG
Keyword(s):  
Corrosion Resistance ◽  
Electron Beam ◽  
Thermal Barrier Coating ◽  
Corrosion Behavior ◽  
Bond Coat ◽  
Hot Corrosion ◽  
Thermal Barrier ◽  
Average Mass ◽  
Barrier Coating ◽  
Corrosion Behaviors

The bare superalloy DZ 125 alloy, the aluminide coated specimens and electron beam physical vapor deposited (EB-PVD) thermal barrier coating (TBC) consisting of yttria stabilizied zirconia (YSZ) topcoat and NiCoCrAlY bond coat specimens were exposed to atomized seawater and kerosene at 900°C and the cyclic hot-corrosion behaviors of the specimens were investigated. Disastrous spallation of the bare superalloy occurred within 50 h hot-corrosion. In contrast to this, after 100 h hot-corrosion, the average mass change for the aluminized and TBC coated specimens is 0.7 mg/cm2 and 0.63 mg/cm2, respectively, exhibiting excellent hot-corrosion resistance.

Effect of Double Electron Beam Remelting on Microstructure of HVOF and CGDS Bond Coat

2017 ◽  
Vol 891 ◽  
pp. 574-578
Author(s):  
Petra Gavendová Krajňáková ◽  
Ivo Dlouhy ◽  
Jan Čížek ◽  
Jan Čupera ◽  
Ruslan Shvab
Keyword(s):  
Electron Beam ◽  
Bond Coat ◽  
Cold Gas Dynamic Spraying ◽  
X Ray Diffraction ◽  
Promising Alternative ◽  
Porosity Level ◽  
Low Temperature Processing ◽  
Modification Technique ◽  
Oxygen Fuel ◽  
Super Alloy

This work focuses to investigate the influence of the parameters used in electron beam (EB) remelting including the effect of double remelting of CoNiCrAlY coatings fabricated on Nickel based super alloy substrates by using the high velocity oxygen-fuel (HVOF) and cold gas dynamic spraying (CGDS) methods. The microstructures of as sprayed and remelted coatings were investigated by scanning electron microscopy and the phase analysis by X-ray diffraction (XRD). The results obtained show that there are advantages at using the pulsed EB surface modification technique. Double EB treatment provides a smooth surface and low porosity level and at last but not least this study demonstrate that low-temperature processing of CoNiCrAlY bond coat represents an interesting and promising alternative for their manufacturing.

scholarly journals Microstructure modification of AISI1045 steel induced by high-current pulsed pseudospark electron beam

Procedia CIRP ◽  
2020 ◽  
Vol 95 ◽  
pp. 972-975
Author(s):  
Yulei Fu ◽  
Jing Hu ◽  
Wansheng Zhao ◽  
Fujun Peng ◽  
Weijie Huo ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Current ◽  
Microstructure Modification ◽  
Aisi1045 Steel

scholarly journals Isothermal Oxidation Behavior of Gadolinium Zirconate (Gd2Zr2O7) Thermal Barrier Coatings (TBCs) produced by Electron Beam Physical Vapor Deposition (EB-PVD) technique

2018 ◽  
Vol 16 (1) ◽  
pp. 986-991 ◽  
Author(s):  
Kadir Mert Doleker ◽  
Yasin Ozgurluk ◽  
Hayrettin Ahlatci ◽  
Abdullah Cahit Karaoglanli
Keyword(s):  
Electron Beam ◽  
Thermal Barrier Coatings ◽  
Vapor Deposition ◽  
Bond Coat ◽  
Physical Vapor Deposition ◽  
Isothermal Oxidation ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
X Ray

AbstractThermal Barrier Coatings (TBCs) provide thermal insulation for gas turbine components operating at high temperatures. Generally, TBCs were produced on a MCrAlY bond coat with 7-8% Yttria Stabilized Zirconia (YSZ) using Atmospheric Plasma Spray (APS) technique. In this study, Inconel 718 substrate material was coated with CoNiCrAlY bond coat using high velocity oxygen fuel (HVOF) technique. Afterward, Gd2Zr2O7 was deposited on samples using Electron Beam Physical Vapor Deposition (EB-PVD) technique. Produced TBCs were exposed to isothermal oxidation tests at 1000°C for 8 h, 24 h, 50 h and 100 h in muffle furnace. Scanning electron microscopy-energy distribution X-ray (SEM-EDX) spectroscopy was used to investigate thermally grown oxide (TGO) layer and TGO growth behavior of TBCs. In addition, X-ray Diffractometer (XRD) analysis was performed to TBCs to understand whether phase transformation occurs or not before and after oxidation.

scholarly journals Evaluation of Commercial Coatings on MarM-002, IN-939 and CM-247 Substrates

1996 ◽  
Author(s):  
J. G. Goedjen ◽  
G. P. Wagner
Keyword(s):  
Electron Beam ◽  
Vapor Deposition ◽  
Bond Coat ◽  
Physical Vapor Deposition ◽  
Thermally Grown Oxide ◽  
Department Of Energy ◽  
Superior Performance ◽  
Air Plasma ◽  
Bond Coats ◽  
Plasma Sprayed

As part of the U.S. Department of Energy Advanced Turbine Systems Program, the performance of Chromalloy RT122, RT122 over RT69 and the Howmet 150L bond coats were evaluated for use in the next generation of Westinghouse combustion turbines. Air plasma sprayed and electron beam physical vapor deposition 8% yttria stabilized zirconia thermal barrier coatings were applied to the bond coats. The coating systems were evaluated in air at 2102°F (1150°C), cooling to room temperature once per day. The life-limiting failure mode in both air plasma sprayed (APS) and electron beam - physical vapor deposition (EB-PVD) coating systems is the oxidation of the bond coat. The coating life is related to the growth rate and morphology of the thermally grown oxide. The superior performance of RT122 on MarM-002, the duplex bond coat system of RT122 over RT69 on MarM-002 and Howmet 150L on MarM-002 can be related to the development of a uniform, slow growing oxide scale. The development of a non-uniform oxidation front contributes to the reduced life of RT122 on IN-939 and CM-247.

scholarly journals Enhancing the Oxidation Resistance of NiCrAlY Bond Coat by High-Current Pulsed Electron Beam Irradiation

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 912
Author(s):  
Xianxiu Mei ◽  
Xiaonan Zhang ◽  
Lisong Zhang ◽  
Na Li ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Oxidation Resistance ◽  
Thermal Barrier Coating ◽  
Bond Coat ◽  
Electron Beam Irradiation ◽  
Thermal Barrier ◽  
High Current ◽  
Beam Irradiation ◽  
Pulsed Electron Beam ◽  
Barrier Coating

The bond coat of a NiCrAlY thermal barrier coating plays an important role in solving the thermal expansion mismatch between a metal matrix and a ceramic layer and in improving the oxidation resistance of the whole thermal barrier coating. However, the NiCrAlY bond coat prepared by low-pressure plasma spraying is not conducive to its oxidation resistance because its lamellar structure is loose, porous and the surface is rough. To improve the oxidation resistance of the bond coat, the NiCrAlY bond coat prepared by plasma spraying was modified by high-current pulsed electron beam with different energy densities. Under the electron beam irradiation, the surface of the coating became smooth, and there was a 3–5 μm thick remelting layer on the surface. Under the irradiation, the thickness of the thermal growth oxide layer decreased, and the oxidation resistance was significantly improved, the oxidation product being mainly Al2O3.

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