scholarly journals Blade Deterioration in a Gas Turbine Engine

1998 ◽  
Vol 4 (4) ◽  
pp. 233-241 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed ◽  
V. Shanov
Keyword(s):  
Stainless Steel ◽  
Gas Turbine ◽  
Protective Coatings ◽  
Aluminide Coating ◽  
Three Dimensional ◽  
Erosive Wear ◽  
Surface Erosion ◽  
Blade Surface ◽  
Erosion Model ◽  
Vapor Deposition Technique

A study has been conducted to predict blade erosion of gas turbine engines. The blade material erosion model is based on three dimensional particle trajectory simulation in the three-dimensional turbine flow field. The trajectories provide the special distribution of the particle impact parameters over the blade surface. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions, is used in the prediction of blade surface erosion based on the trajectory impact data. To improve the blade erosion resistance and to decrease the blade deterioration, the blades must be coated. For this purpose, an experimental study was conducted to investigate the behavior of rhodium platinum aluminide coating exposed to erosion by fly ash particles. New protective coatings are developed for erosion and thermal barrier. Chemical vapor deposition technique (CVD) was used to apply the ceramic TiC coatings on INCO 718 and stainless steel 410. The erosive wear of the coated samples was investigated experimentally by exposing them to particle laden flow at velocities from 180 to 305m/s and temperatures from ambient to538°C in a specially designed erosion wind tunnel. Both materials (INCO 718 and stainless steel 410) coated with CVD TiC showed one order of magnitude less erosion rate compared to some commercial coatings on the same substrates.

Blade Erosion in Automotive Gas Turbine Engine

1995 ◽  
Vol 117 (1) ◽  
pp. 213-219 ◽  
Author(s):  
M. Metwally ◽  
W. Tabakoff ◽  
A. Hamed
Keyword(s):  
Gas Turbine ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Particulate Flow ◽  
Particle Impact ◽  
Surface Erosion ◽  
Blade Surface ◽  
Erosion Model ◽  
Turbine Engine ◽  
Automotive Engine

In this work, a study has been conducted to predict blade erosion and surface deterioration of the free power turbine of an automotive gas turbine engine. The blade material erosion model is based on three-dimensional particle trajectory simulations in the three-dimensional turbine flow field. The particle rebound characteristics after surface impacts were determined from experimental measurements of restitution ratios for blade material samples in a particulate flow tunnel. The trajectories provide the spatial distribution of the particle impact parameters over the blade surfaces. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions, is used in the prediction of blade surface erosion based on the trajectory impact data. The results are presented for the three-dimensional particle trajectories through the turbine blade passages, the particle impact locations, blade surface erosion pattern, and the associated erosion parameters. These parameters include impact velocity, impact angle, and impact frequency. The data can be used for life prediction and performance deterioration of the automotive engine under investigation.

An Automotive Gas Turbine Engine Blade Erosion

1992 ◽  
Author(s):  
M. Metwally ◽  
W. Tabakoff ◽  
A. Hamed
Keyword(s):  
Gas Turbine ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Particulate Flow ◽  
Particle Impact ◽  
Surface Erosion ◽  
Blade Surface ◽  
Erosion Model ◽  
Turbine Engine ◽  
Automotive Engine

In this work, a study has been conducted to predict blade erosion and surface deterioration of the free power turbine of an automotive gas turbine engine. The blade material erosion model is based on three dimensional particle trajectory simulations in the three dimensional turbine flow field. The particle rebound characteristics after surface impacts were determined from experimental measurements of restitution ratios for blade material samples in a particulate flow tunnel. The trajectories provide the spacial distribution of the particle impact parameters over the blade surfaces. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions is used in the prediction of blade surface erosion based on the trajectory impact data. The results are presented for the three dimensional particle trajectories through the turbine blade passages, the particle impact locations, blade surface erosion pattern, and the associated erosion parameters. These parameters include impact velocity, impact angle and impact frequency. The data can be used for life prediction and performance deterioration of the automotive engine under investigation.

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

Turbine Blade Surface Deterioration by Erosion

2004 ◽  
Author(s):  
Awatef A. Hamed ◽  
Widen Tabakoff ◽  
Richard B. Rivir ◽  
Kaushik Das ◽  
Puneet Arora
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Low Pressure ◽  
Impact Angle ◽  
Rotor Blades ◽  
Material Surface ◽  
Surface Erosion ◽  
Blade Surface ◽  
Suction Surface ◽  
Particle Trajectories

This paper presents the results of a combined experimental and computational research program to investigate turbine vane and blade material surface deterioration caused by solid particle impacts. Tests are conducted in the erosion wind tunnel for coated and uncoated blade materials at various impact conditions. Surface roughness measurements obtained prior and subsequent to the erosion tests are used to characterize the change in roughness caused by erosion. Numerical simulations for the three dimensional flow field and particle trajectories through a low pressure gas turbine are employed to determine the particle impact conditions with stator vanes and rotor blades using experimentally-based particle restitution models. Experimental results are presented for the measured blade material/coating erosion and surface roughness. The measurements indicate that both erosion and surface roughness increase with impact angle and particle size. Computational results are presented for the particle trajectories though the first stage of a low-pressure turbine of a high bypass turbofan engine. The trajectories indicate that the particles impact the vane pressure surface and the aft part of the suction surface. The impacts reduce the particle momentum through the stator but increase it through the rotor. Vane and blade surface erosion patterns are predicted based on the computed trajectories and the experimentally measured blade coating erosion characteristics.

Protective coatings of nanophase diamond deposited directly on stainless steel substrates

1996 ◽  
Vol 11 (8) ◽  
pp. 2042-2050 ◽  
Author(s):  
F. Davanloo ◽  
H. Park ◽  
C. B. Collins
Keyword(s):  
Stainless Steel ◽  
High Speed ◽  
Protective Coatings ◽  
Diamond Films ◽  
Erosive Wear ◽  
High Energy ◽  
Industrial Applications ◽  
Carbon Ions ◽  
Interfacial Layers ◽  
Steel Substrates

Composed of sp3 bonded nodules of carbon, nanophase diamond films are deposited in vacuum onto almost any substrate by condensing carbon ions carrying keV energies. These multiply charged ions are obtained from the laser ablation of graphite at intensities in excess of 1011 W cm−2. The high energy of condensation provides both the chemical bonding of such films to a wide variety of substrates and low values of residual compressive stress. Coatings of 2–5 μm thickness have extended lifetimes of materials such as Si, Ti, ZnS, ZnSe, and Ge against the erosive wear from high-speed particles by factors of tens to thousands. In this research emphasis has been placed on studies of the bonding and properties realized by the direct deposition of nanophase diamond films on stainless steel substrates. Examinations of interfacial layers showed deep penetrations of carbon atoms into steel substrates. Resistances to low and high impact wear estimated by a tumbler device and a modified sand blaster, respectively, and results indicated significant increases in the lifetime of stainless steel samples. The characterization studies in this work demonstrated nanophase diamond as an attractive material for use as a protective coating in current industrial applications.

Turbine Blade Surface Deterioration by Erosion

2004 ◽  
Vol 127 (3) ◽  
pp. 445-452 ◽  
Author(s):  
Awatef A. Hamed ◽  
Widen Tabakoff ◽  
Richard B. Rivir ◽  
Kaushik Das ◽  
Puneet Arora
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Low Pressure ◽  
Impact Angle ◽  
Rotor Blades ◽  
Material Surface ◽  
Surface Erosion ◽  
Blade Surface ◽  
Suction Surface ◽  
Particle Trajectories

This paper presents the results of a combined experimental and computational research program to investigate turbine vane and blade material surface deterioration caused by solid particle impacts. Tests are conducted in the erosion wind tunnel for coated and uncoated blade materials at various impact conditions. Surface roughness measurements obtained prior and subsequent to the erosion tests are used to characterize the change in roughness caused by erosion. Numerical simulations for the three-dimensional flow field and particle trajectories through a low-pressure gas turbine are employed to determine the particle impact conditions with stator vanes and rotor blades using experimentally based particle restitution models. Experimental results are presented for the measured blade material/coating erosion and surface roughness. The measurements indicate that both erosion and surface roughness increase with impact angle and particle size. Computational results are presented for the particle trajectories through the first stage of a low-pressure turbine of a high bypass turbofan engine. The trajectories indicate that the particles impact the vane pressure surface and the aft part of the suction surface. The impacts reduce the particle momentum through the stator but increase it through the rotor. Vane and blade surface erosion patterns are predicted based on the computed trajectories and the experimentally measured blade coating erosion characteristics.

scholarly journals Protective Coatings and Degradation Experiences for First Stage Buckets on GE MS-5002B/C Gas Turbines

1996 ◽  
Author(s):  
Refrizal Boestaman ◽  
V. P. Swaminathan ◽  
H. L. Bernstein
Keyword(s):  
Gas Turbine ◽  
Firing Temperature ◽  
Gas Turbines ◽  
Single Phase ◽  
Protective Coatings ◽  
Aluminide Coating ◽  
Diffusion Coating ◽  
Chemical Vapor ◽  
Total Power ◽  
Platinum Aluminide

PT Arun operates 21 GE Model MS-5002 B/C gas turbines as mechanical drive with a total power of 514 MW, and a total of 2.7 million hours of accumulated operation. The first generations of simple cycle gas turbines were designed at 1700 F (927 C) firing temperature using first stage buckets design cast from IN-738LC and coated with a conventional 2-phase platinum aluminide coating (Pt-Al). Since 1989, the output power was increased by raising gas turbine firing temperature to 1770 F (965 C). This uprate was implemented by using first stage buckets cast from GTD-111 DS and coated with GT-29 Plus. Metallurgical examination of these coatings at various operating hours have been performed to check their performance and the cause of coating degradation. These results are considered for future coating selection. In the last two years PT Arun has explored a new single phase NiCoCrAlY coating and a single phase Pt-Al diffusion coating using chemical vapor disposition process as an alternate to GT-29 plus coating replacement. Both of these coatings are used at PT Arun and have accumulated 32,400 hours for NiCoCrAlY or GT-33 and 2880 hours for single phase Pt-Al or MDC-150L coating as of June 1996. The information regarding qualification of these alternate coatings (zero running hours) will be discussed in this paper.

Coating Effect on Particle Trajectories and Turbine Blade Erosion

1992 ◽  
Vol 114 (2) ◽  
pp. 250-257 ◽  
Author(s):  
W. Tabakoff ◽  
M. Metwally
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Axial Flow ◽  
Coal Ash ◽  
Impact Angle ◽  
Laser Doppler Velocimeter ◽  
Particle Trajectories

Gas turbine engines operating in dusty environments are exposed to erosion and performance deterioration. In order to improve the erosion resistance, nickel and cobalt superalloy blades and vanes are widely used in the hot section of gas turbines. Protective coatings have been used to enhance superalloy resistance to hot erosion. An investigation has been conducted to study coal ash particle dynamics and resulting blade erosion for both uncoated and coated blades of a two-stage axial flow gas turbine. A quasi-three-dimensional flow solution is obtained for each blade row for accurate computation of particle trajectories. The change in particle momentum due to collision with the turbine blades and casings is modeled using restitution parameters derived from three-component laser-Doppler velocimeter measurements. The erosion models for both blade superalloy and coatings are derived based on the erosion data obtained by testing the blade superalloy and coatings in a high-temperature erosion wind tunnel. The results show both the three-dimensional particle trajectories and the resulting blade impact locations for both uncoated and coated blade surfaces. In addition are shown the distribution of the erosion rate, impact frequency, impact velocity, and impact angle for the superalloy and the coating. The results indicate significant effects of the coating, especially on blade erosion and material deterioration.

Field Evaluation of Gas Turbine Protective Coatings

1988 ◽  
Vol 110 (1) ◽  
pp. 142-149 ◽  
Author(s):  
A. McMinn ◽  
R. Viswanathan ◽  
C. L. Knauf
Keyword(s):  
Gas Turbine ◽  
Cross Sections ◽  
Hot Corrosion ◽  
Protective Coatings ◽  
Aluminide Coating ◽  
Fatigue Cracking ◽  
Poor Performance ◽  
Field Evaluation ◽  
Cobalt Chromium ◽  
Metallographic Examination

The hot corrosion resistance of several protective coatings that had been applied to MAR-M-509 nozzle guide vanes and exposed in a utility gas turbine has been evaluated. The coatings included basic aluminide, rhodium-aluminide, platinum-rhodium-aluminide, and palladium-aluminide diffusion coatings, and cobalt-chromium-aluminum-yttrium (CoCrAlY) and ceramic overlay coatings. A combination of metallographic examination of vane cross sections and energy dispersive X-ray analysis (EDS) was employed in the evaluation. The results showed that none of the coatings was totally resistant to corrosive attack. The CoCrAlY and platinum-rhodium-aluminide coatings exhibited the greatest resistance to hot corrosion. The CoCrAlY coated vanes were, however, susceptible to thermal fatigue cracking. Except for the poor performance of the palladium-aluminide coating, the precious metal aluminides offered the best protection against corrosion. Hot isostatically pressing coatings was not found to be beneficial, and in one case appeared detrimental.

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