Effect of increased water vapor levels on TBC lifetime with Pt-containing bond coatings

2011 ◽  
Vol 206 (7) ◽  
pp. 1566-1570 ◽  
Author(s):  
B.A. Pint ◽  
G.W. Garner ◽  
T.M. Lowe ◽  
J.A. Haynes ◽  
Y. Zhang
Keyword(s):  
Water Vapor ◽  
Bond Coatings ◽  
Tbc Lifetime

The Effect of Environment on TBC Lifetime

2015 ◽  
Author(s):  
Bruce A. Pint ◽  
Kinga A. Unocic ◽  
J. Allen Haynes
Keyword(s):  
Water Vapor ◽  
Carbon Capture ◽  
Air Plasma ◽  
Combustion Gas ◽  
Bond Coatings ◽  
Barrier Coating ◽  
Coating Failure ◽  
Negative Effect ◽  
Plasma Sprayed ◽  
Tbc Lifetime

While the water vapor content of the combustion gas in natural gas-fired land based turbines is ∼10%, it can be 20–85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1 and 100h cycles) were performed in air with 10, 50 and 90 vol.% water vapor and CO2-10%H2O and compared to prior results in dry air or O2. Two types of TBC’s were investigated: (1) diffusion bond coatings (Pt diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air-plasma sprayed YSZ top coatings on superalloys X4, 1483 or 247 substrates. For both types of coatings exposed in 1h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt diffusion coatings which were unaffected by the environment. In 100h cycles, environment was less critical, perhaps because coating failure was chemical (i.e. due to interdiffusion) rather than mechanical. In both 1h and 100h cycles, CO2 did not appear to have any negative effect on coating lifetime.

scholarly journals The Effect of Environment on Thermal Barrier Coating Lifetime

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Bruce A. Pint ◽  
Kinga A. Unocic ◽  
J. Allen Haynes
Keyword(s):  
Water Vapor ◽  
Thermal Barrier Coating ◽  
Carbon Capture ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Combustion Gas ◽  
Bond Coatings ◽  
Barrier Coating ◽  
Negative Effect ◽  
Plasma Sprayed

While the water vapor content of the combustion gas in natural gas-fired land-based turbines is ∼10%, it can be 20–85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1-h and 100-h cycles) were performed in air with 10, 50, and 90 vol. % water vapor and CO2-10% H2O and compared to prior results in dry air or O2. Two types of TBCs were investigated: (1) diffusion bond coatings (Pt-diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high-velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air plasma-sprayed YSZ top coatings on superalloys X4, 1483, or 247 substrates. For both types of coatings exposed in 1-h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt-diffusion coatings which were unaffected by the environment. In 100-h cycles, environment was less critical, perhaps because coating failure was chemical (i.e., due to interdiffusion) rather than mechanical. In both 1-h and 100-h cycles, CO2 did not appear to have any negative effect on coating lifetime.

scholarly journals The effect of cycle frequency, H2O and CO2 on TBC lifetime with NiCoCrAlYHfSi bond coatings

2014 ◽  
Vol 260 ◽  
pp. 107-112 ◽  
Author(s):  
M.J. Lance ◽  
K.A. Unocic ◽  
J.A. Haynes ◽  
B.A. Pint
Keyword(s):  
Cycle Frequency ◽  
Bond Coatings ◽  
Tbc Lifetime

scholarly journals The Effect of Coating Composition and Geometry on TBC Lifetime

2017 ◽  
Author(s):  
Bruce A. Pint ◽  
Michael J. Lance ◽  
J. Allen Haynes
Keyword(s):  
Gas Turbines ◽  
Average Lifetime ◽  
Air Plasma ◽  
Bond Coatings ◽  
Bond Coating ◽  
Negative Effect ◽  
Plasma Sprayed ◽  
Oxygen Fuel ◽  
Thermally Sprayed ◽  
Tbc Lifetime

Several factors are being investigated that affect the performance of thermal barrier coatings (TBC) for use in land-based gas turbines where coatings are mainly thermally sprayed. This study examined high velocity oxygen fuel (HVOF), air plasma sprayed (APS) and vacuum plasma sprayed (VPS) MCrAlYHfSi bond coatings with APS YSZ top coatings at 900°–1100°C. For superalloy 247 substrates and VPS coatings tested in 1-h cycles at 1100°C, removing 0.6wt.%Si had no effect on average lifetime in 1-h cycles at 1100°C, but adding 0.3%Ti had a negative effect. Rod specimens were coated with APS, HVOF and HVOF with an outer APS layer bond coating and tested in 100-h cycles in air+10%H2O at 1100°C. With an HVOF bond coating, initial results indicate that 12.5 mm diameter rod specimens have much shorter 100-h cycle lifetimes than disk specimens. Longer lifetimes were obtained when the bond coating had an inner HVOF layer and outer APS layer.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

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