Current Search: Thermal Stress (x)
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- Title
- A DYNAMIC MODEL OF THE HUMAN/COOLINGSYSTEM/CLOTHING/ENVIRONMENT SYSTEM.
- Creator
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pu, zhengxiang, Kapat, Jayanta, University of Central Florida
- Abstract / Description
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The human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where...
Show moreThe human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where ambient environmental cooling is not economically viable or feasible. It is important to predict the physiological responses of a person wearing PPE with personal cooling to make sure that the individual is free of heat stress, as well as any additional discomfort that may occur. Air temperature, radiant temperature, humidity and air movement are the four basic environmental parameters that affect human response to thermal environments. Combined with the personal parameters of metabolic heat generated by human activity and clothing worn by a person, they provide the six fundamental factors which define human thermal environments. If personal cooling system is available, the fluid flow speed, cooling tube distribution density and fluid inlet temperature have significant effects on the human thermal comfort. It is impractical to evaluate the problem experimentally due to too many factors involved. A thermal model was developed to improve human body thermal comfort prediction. The system researched includes human body, personal cooling system, clothing and environment. An existing model of thermoregulation is taken as a starting point. Changes and additions are made to provide better prediction. Personal cooling model was developed and it includes liquid cooling model, air cooling model and ice cooling model. Thermal resistance networks for the cooling system are built up; additionally a combined model of heat and mass transfer from cooling garment through clothing to environment is developed and incorporated into the personal cooling model and thermoregulatory model. The control volume method is employed to carry out the numerical calculation. An example simulation is presented for extra-vehicular activities on Mars. The simulation results agree well with available experimental data, though a small discrepancy between simulation results and experimental data is observed during the beginning of the cooling process. Compared with a water cooling lumped model, the thermal model provides a much better prediction. For water cooling, parametric study shows that the cooling water inlet temperature and liner thermal resistance have great effects on the maximum exposure time; PPE resistance and cooling water flow rate do not have much impact on the maximum exposure time. For air cooling, cooling air flow rate, inlet temperature, relative humidity and liner resistance have great effects on the maximum exposure time.
Show less - Date Issued
- 2005
- Identifier
- CFE0000416, ucf:46407
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000416
- Title
- MECHANISMS OF LIFETIME IMPROVEMENT IN THERMAL BARRIER COATINGS WITH HF AND/OR Y MODIFICATION OF CMSX-4 SUPERALLOY SUBSTRATES.
- Creator
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Liu, Jing, Sohn, Yong ho, University of Central Florida
- Abstract / Description
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In modern turbine engines for propulsion and energy generation, thermal barrier coating (TBCs) protect hot-section blades and vanes, and play a critical role in enhancing reliability, durability and operation efficiency. In this study, thermal cyclic lifetime and microstructural degradation of electron beam physical vapor deposited (EB-PVD) Yttria Stabilized Zirconia (YSZ) with (Ni,Pt)Al bond coat and Hf- and/or Y- modified CMSX-4 superalloy substrates were examined. Thermal cyclic lifetime...
Show moreIn modern turbine engines for propulsion and energy generation, thermal barrier coating (TBCs) protect hot-section blades and vanes, and play a critical role in enhancing reliability, durability and operation efficiency. In this study, thermal cyclic lifetime and microstructural degradation of electron beam physical vapor deposited (EB-PVD) Yttria Stabilized Zirconia (YSZ) with (Ni,Pt)Al bond coat and Hf- and/or Y- modified CMSX-4 superalloy substrates were examined. Thermal cyclic lifetime of TBCs was measured using a furnace thermal cycle test that consisted of 10-minute heat-up, 50-minute dwell at 1135C, and 10-minute forced-air-quench. TBC lifetime was observed to improve from 600 cycles to over 3200 cycles with appropriated Hf- and/or Y alloying of CMSX-4 superalloys. This significant improvement in TBC lifetime is the highest reported lifetime in literature with similar testing parameters. Beneficial role of reactive element (RE) on the durability of TBCS were systematically investigated in this study. Photostimulated luminescence spectroscopy (PL) was employed to non-destructively measure the residual stress within the TGO scale as a function of thermal cycling. Extensive microstructural analysis with emphasis on the YSZ/TGO interface, TGO scale, TGO/bond coat interface was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning electron microscopy (STEM) as a funcion of thermal cycling including after the spallation failure. Focused ion beam in-situ lift-out (FIB-INLO) technique was employed to prepare site-specific TEM specimens. X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) were also employed for phase identification and interfacial chemical analysis. While undulation of TGO/bond coat interface (e.g., rumpling and ratcheting) was observed to be the main mechanism of degradation for the TBCs on baseline CMSX-4, the same interface remained relatively flat (e.g., suppressed rumpling and ratcheting) for durable TBCs on Hf- and/or Y-modified CMSX-4. The fracture paths changed from the YSZ/TGO interface to the TGO/bond coat interface when rumpling was suppressed. The geometrical incompatibility between the undulated TGO and EB-PVD YSZ lead to the failure at the YSZ/TGO interface for TBCs with baseline CMSX-4. The magnitude of copressive residual stress within the TGO scale measured by PL gradually decreased as a function of thermal cycling for TBCs with baseline CMSX-4 superalloy substrates. This gradual decrease corrsponds well to the undulation of the TGO scale that may lead to relaxation of the compressive residual stress within the TGO scale. For TBCs with Hf- and/or Y-modified CMSX-4 superalloy substrates, the magnitude of compressive residual stress within the TGO scale remained relatively constant throughout the thermal cycling, although PL corresponding to the stress-relief caused by localized cracks at the TGO/bond coat interface and within the TGO scale was observed frequently starting 50% of lifetime. A slightly smaller parabolic growth constant and grain size of the TGO scale was observed for TBCs with Hf- and/or Y- modified CMSX-4. Small monoclinic HfO2 precipitates were observed to decorate grain boundaries and the triple pointes within the alpha-Al2O3 scale for TBCs with Hf- and/or Y-modified CMSX-4 substrates. Segregation of Hf/Hf4+ at the TGO/bond coat interfaces was also observed for TBCs with Hf- and/or Y-modified CMSX-4 superalloys substrates. Adherent and pore-free YSZ/TGO interface was observed for TBCs with Hf- and/or Y-modified CMSX-4, while a significant amount of decohesion at the YSZ/TGO interface was observed for TBCs with baseline CMSX-4. The beta-NiAl(B2) phase in the (Ni,Pt)Al bond coat was observed to partially transform into gama prime-Ni3Al (L12) phase due to depletion of Al in the bond coat during oxidation. More importantly, the remaining beta-NiAl phase transformed into L10 martensitic phase upon cooling even though there was no significant difference in these phase transformations for all TBCs. Results from these microstructural observations are documented to elucidate mechanisms that suppress the rumpling of the TGO/bond coat interface, which is responsible for superior performance of EB-PVD TBCs with (Ni,Pt)Al bond coat and Hf- and/or Y-modified CMXS-4 superalloy.
Show less - Date Issued
- 2007
- Identifier
- CFE0001872, ucf:47382
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001872
- Title
- METHOD TO DISCRETIZE CONTINUOUS GRADIENT STRUCTURES AND CALCULATE THERMAL RESIDUAL STRESSES WITHIN LAYERED FUNCTIONALLY GRADED CERAMICS.
- Creator
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Neale, Ryan E, Orlovskaya, Nina, University of Central Florida
- Abstract / Description
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Functionally graded materials (FGMs) are an advanced class of material which seeks to leverage the strengths of one material to mitigate the weaknesses of another. This allows for operation in extreme environments or conditions where materials properties must change at various locations within a structure. Fabrication of this advanced class of material is limited due to geometric, economic, and material constraints inherent in the various methods. For this reason, a model was developed to...
Show moreFunctionally graded materials (FGMs) are an advanced class of material which seeks to leverage the strengths of one material to mitigate the weaknesses of another. This allows for operation in extreme environments or conditions where materials properties must change at various locations within a structure. Fabrication of this advanced class of material is limited due to geometric, economic, and material constraints inherent in the various methods. For this reason, a model was developed to discretize continuous gradient curves to allow for the use of a step-wise approximations to such gradients. These alternative step-wise gradients would allow for the use of numerous manufacturing techniques which have improved composition control, cost of processing, cost of equipment, and equipment availability. One such technique, tape casting, was explored due to its robustness and ability to create layered ceramics. Since ceramics are inherently brittle materials, they serve to be strengthened by the thermal residual stresses that form in the creation of these step-wise graded composites. With models to calculate these residual stresses and determine step-wise approximations of various compositional gradients, the process of designing these layered ceramics can be significantly improved.
Show less - Date Issued
- 2019
- Identifier
- CFH2000530, ucf:45633
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000530
- Title
- Analysis of residual stress and damage mechanisms of thermal barrier coatings deposited via PS-PVD and EB-PVD.
- Creator
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Rossmann, Linda, Raghavan, Seetha, Sohn, Yongho, Vaidyanathan, Raj, Ghosh, Ranajay, University of Central Florida
- Abstract / Description
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Thermal barrier coatings (TBCs) are critical to gas turbine engines, as they protect the components in the hot section from the extreme temperatures of operation. The current industry standard method of applying TBCs for turbine blades in jet engines is electron-beam physical vapor deposition (EB-PVD), which results in a columnar structure that is valued for its high degree of strain tolerance. An emerging deposition method is plasma-spray physical vapor deposition (PS-PVD), capable of...
Show moreThermal barrier coatings (TBCs) are critical to gas turbine engines, as they protect the components in the hot section from the extreme temperatures of operation. The current industry standard method of applying TBCs for turbine blades in jet engines is electron-beam physical vapor deposition (EB-PVD), which results in a columnar structure that is valued for its high degree of strain tolerance. An emerging deposition method is plasma-spray physical vapor deposition (PS-PVD), capable of producing a variety of customizable microstructures as well as non-line-of-sight deposition, which allows more complex geometries to be coated, or even multiple parts at once. The pseudo-columnar microstructure that can be produced with PS-PVD is a possible alternative to EB-PVD. However, before PS-PVD can be used to its full potential, its mechanical properties and behavior must be understood. This work contributes to this understanding by characterizing PS-PVD TBCs that have been thermally cycled to simulate multiple lifetimes (0, 300, and 600 thermal cycles). Residual stress in the thermally grown oxide (TGO) layer is characterized by photoluminescence piezospectroscopy as TGO residual stress is correlated with the lifetime of the coating. Residual stress in the top coat is characterized by Raman spectroscopy, because this stress drives cracking in the top coat that can lead to failure. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) are performed to observe microstructural and phase evolution to provide context and possible explanations for the stress results. In addition, EB-PVD samples of the same thermal cycling history are characterized in the same way so that PS-PVD can be benchmarked against the industry standard. The compressive residual stress in the TGO in both coatings was relieved with thermal cycling due to the TGO lengthening as well as microcracking. The PS-PVD samples had slightly lower TGO stress than the EB-PVD, which is attributed to the greater extent of cracking within the TGO, whereas cracking in the EB-PVD samples was at the TGO/topcoat interface. The PS-PVD cycled samples had significant cracking within the topcoat near the TGO due to both greater porosity than EB-PVD samples and regions of unmelted particles that provide little resistance to cracking. The greater convolution of the TGO in the PS-PVD samples results in greater out-of-plane tensile stresses that cause crack initiation, as well as diverts cracks away from the difficult-to-follow interface. The TGO stress results agree with existing literature and extend the thermal cycling beyond what has previously been reported for PS-PVD coatings, revealing a trend of stress relief and stress values similar to that of EB-PVD coatings in this study and in the literature. Residual stress in the topcoat for both coating types became increasingly compressive with thermal cycling, indicating loss of strain tolerance by sintering. The trend of the YSZ stress for both coating types to become more compressive with cycling and with depth agrees with the literature, and the thermal cycling is longer than has been previously reported for PS-PVD. The two coating types had quite different microstructures and crack modes as well as different as-deposited residual stresses, but after thermal cycling had similar stresses in both the TGO and top coat. No samples experienced spallation. These results indicate that, while PS-PVD coatings have different properties and behavior from EB-PVD coatings, they had comparable levels of damage to EB-PVD coatings of the same lifetime and are a viable alternative to EB-PVD. Further tuning of the processing parameters may result in PS-PVD coatings with even more similar behavior to EB-PVD coatings.
Show less - Date Issued
- 2019
- Identifier
- CFE0007717, ucf:52429
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007717
- Title
- In-situ synchrotron studies of turbine blade thermal barrier coatings under extreme environments.
- Creator
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Knipe, Kevin, Raghavan, Seetha, Gordon, Ali, Kapat, Jayanta, Sohn, Yongho, University of Central Florida
- Abstract / Description
-
Thermal Barrier Coatings have been used for decades to impose a thermal gradient between the hot combustion gases and the underlying superalloy substrate in engine turbine blades. Yttria Stabilized Zirconia (YSZ) is an industry standard high temperature ceramic for turbine applications. The protective coating is adhered to the substrate using a nickel based alloy bond coat. Through exposure to high temperature, a Thermally Grown Oxide (TGO) layer develops at the bond coat-YSZ interface. Large...
Show moreThermal Barrier Coatings have been used for decades to impose a thermal gradient between the hot combustion gases and the underlying superalloy substrate in engine turbine blades. Yttria Stabilized Zirconia (YSZ) is an industry standard high temperature ceramic for turbine applications. The protective coating is adhered to the substrate using a nickel based alloy bond coat. Through exposure to high temperature, a Thermally Grown Oxide (TGO) layer develops at the bond coat-YSZ interface. Large residual stresses develop in these layers due to thermal expansion mismatch that occurs during cool down from high temperature spraying and cyclic operating conditions. Despite their standard use, much is to be determined as to how these residual stresses are linked to the various failure modes. This study developed techniques to monitor the strain and stress in these internal layers during thermal gradient and mechanical conditions representing operating conditions. The thermal gradient is applied across the coating thickness of the tubular samples from infrared heating of the outer coating and forced air internal cooling of the substrate. While thermal and mechanical loading conditions are applied, 2-dimensional diffraction measurements are taken using the high-energy Synchrotron X-Rays and analyzed to provide high-resolution depth-resolved strain. This study will include fatigue comparisons through use of samples, which are both 'as-coated' as well as aged to various stages in a TBC lifespan. Studies reveal that variations in thermal gradients and mechanical loads create corresponding trends in depth resolved strains with the largest effects displayed at or near the bond coat/TBC interface. Single cycles as well as experiments targeting thermal gradient and mechanical effects were conducted to capture these trends. Inelastic behavior such as creep was observed and quantified for the different layers at high temperatures. From these studies more accurate lifespan predictions, material behaviors, and causes of failure modes can be determined. The work further develops measurement and analysis techniques for diffraction measurements in internal layers on a coated tubular sample which can be used by various industries to analyze similar geometries with different applications.
Show less - Date Issued
- 2014
- Identifier
- CFE0005640, ucf:50206
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005640
- Title
- EVOLUTION OF MICROSTRUCTURE AND RESIDUAL STRESS IN DISC-SHAPE EB-PVD THERMAL BARRIER COATINGS AND TEMPERATURE PROFILE OF HIGH PRESSURE TURBINE BLADE.
- Creator
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Mukherjee, Sriparna, Sohn, Yongho, University of Central Florida
- Abstract / Description
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A detailed understanding of failure mechanisms in thermal barrier coatings (TBCs) can help develop reliable and durable TBCs for advanced gas turbine engines. One of the characteristics of failure in electron beam physical vapor deposited (EB-PVD) TBCs is the development of instability, named rumpling, at the interface between (Ni, Pt)Al bond coat and thermally grown oxide (TGO). In this study, thermal cycling at 1100[degrees]C with 1 hr dwell time was carried out on 25.4mm disc specimens of...
Show moreA detailed understanding of failure mechanisms in thermal barrier coatings (TBCs) can help develop reliable and durable TBCs for advanced gas turbine engines. One of the characteristics of failure in electron beam physical vapor deposited (EB-PVD) TBCs is the development of instability, named rumpling, at the interface between (Ni, Pt)Al bond coat and thermally grown oxide (TGO). In this study, thermal cycling at 1100[degrees]C with 1 hr dwell time was carried out on 25.4mm disc specimens of TBCs that consisted of EB-PVD coated ZrO2-7wt.%Y2O3, (Pt,Ni)Al bond coat, and CMSX-4 Ni-based superalloy. At specific fraction of lifetime,TBCs were examined by electron microscopy and photostimulated luminescence (PL). Changes in the average compressive residual stress of the TGO determined by PL and the magnitude of rumpling, determined by tortuosity from quantitative microstructural analyses, were examined with respect to the furnace thermal cyclic lifetime and microstructural evolution of TBCs. The combination of elastic strain energy within the TGO and interfacial energy at the interface between the TGO and the bond coat was defined as the TGO energy, and its variation with cyclic oxidation time was found to remain approximately constant ~135J/m2 during thermal cycling from 10% to 80% thermal cyclic lifetime. Parametric study at ~135J/m2 was performed and variation in residual stress with rumpling for different oxide scale thicknesses was examined. This study showed that the contribution of rumpling in residual stress relaxation decreased with an increase in TGO thickness. High pressure turbine blades serviced for 2843 hours and in the as coated form were also examined using electron microscopy and photostimulated luminescence. The difference in residual stress values obtained using PL on the suction and pressure sides of as-coated turbine blade were discussed. The presence of a thick layer of deposit on the serviced blade gave signals from stress free alpha-Al2O3 in the deposit, not from the TGO. The TGO growth constant data from the disc-shape TBCs, thermally cycled at 1100[degrees]C, and studies by other authors at different temperatures but on similar EB-PVD coated TBCs with (Pt, Ni)Al bond coat and CMSX-4 Ni- based superalloy were used to determine the temperature profile at the YSZ/bond coat interface. The interfacial temperature profiles of the serviced blade and the YSZ thickness profile were compared to document the variable temperature exposure at the leading edge, trailing edge, suction and the pressure side.
Show less - Date Issued
- 2011
- Identifier
- CFE0003927, ucf:48700
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003927
- Title
- ZrB2-SiC BASED ULTRA HIGH TEMPERATURE CERAMIC COMPOSITES: MECHANICAL PERFORMANCE AND MEASUREMENT AND DESIGN OF THERMAL RESIDUAL STRESSES FOR HYPERSONIC VEHICLE APPLICATIONS.
- Creator
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Stadelmann, Richard, Orlovskaya, Nina, Kumar, Ranganathan, Raghavan, Seetha, University of Central Florida
- Abstract / Description
-
Ultra-high temperature ceramics (UHTCs), such as ZrB2-based ceramic composites, have been identified as next generation candidate materials for leading edges and nose cones in hypersonic air breathing vehicles. Mechanical performance of ceramic composites play an important role in the ultra-high temperature applications, therefore SiC is added to ZrB2 as a strengthening phase to enhance its mechanical performance. The high melting temperatures of both ZrB2 and SiC, as well as the ability of...
Show moreUltra-high temperature ceramics (UHTCs), such as ZrB2-based ceramic composites, have been identified as next generation candidate materials for leading edges and nose cones in hypersonic air breathing vehicles. Mechanical performance of ceramic composites play an important role in the ultra-high temperature applications, therefore SiC is added to ZrB2 as a strengthening phase to enhance its mechanical performance. The high melting temperatures of both ZrB2 and SiC, as well as the ability of SiC to form SiO2 refractory oxide layers upon oxidation make ZrB2-SiC ceramics very suitable for aerospace applications. Thermal residual stresses appearing during processing are unavoidable in sintered ZrB2-SiC ceramic composites. Residual microstresses appear at the microstructural level (intergranular microstresses) or at the crystal structure level (intragranular microstresses). These microstresses are of enormous importance for the failure mechanisms in ZrB2-SiC ceramics, such as ratio of the trans- and intergranular fracture; crack branching or bridging, microcracking, subcritical crack growth and others, as they govern crack propagation(-)induced energy dissipation and affect the toughness and strength of the ceramic material. Therefore, understanding the evolution of residual stress state in processed ZrB2-SiC ceramic composites and accurate measurements of these stresses are of high priority. In the present research the ZrB2-17vol%SiC, ZrB2-32vol%SiC, and ZrB2-45vol%SiC ultra-high temperature particulate ceramic composites were sintered using both Hot Pressing (HP) and Spark Plasma Sintering (SPS) techniques. The mechanical performance of the ZrB2-SiC composites was investigated using 3- and 4-point bending techniques for measurements of instantaneous fracture strength and fracture toughness. Resonant Ultrasound Spectroscopy was used for measurement of Young's, shear, and bulk moduli as well as Poisson's ratio of the composites. The distribution of thermal residual stresses and the effect of the applied external load on their re-distribution was studied using micro-Raman spectroscopy. Piezospectroscopic coefficients were determined for all compositions of ZrB2-SiC ceramic under study and their experimentally obtained values were compared with the piezospectroscopic coefficients both published in the literature and calculated using theoretical approach. Finally, the novel ZrB2-IrB2-SiC ceramic composites were also produced using Spark Plasma Sintering (SPS), where IrB2 powder was synthesized using mechanochemical route. It is expected that the IrB2 additive phase might contribute to the improved overall oxidation resistance of ZrB2 based ultra-high temperature ceramic composites.
Show less - Date Issued
- 2015
- Identifier
- CFE0006008, ucf:51004
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006008
- Title
- INVESTIGATION OF PS-PVD AND EB-PVD THERMAL BARRIER COATINGS OVER LIFETIME USING SYNCHROTRON X-RAY DIFFRACTION.
- Creator
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Northam, Matthew, Raghavan, Seetha, Ghosh, Ranajay, Vaidyanathan, Raj, University of Central Florida
- Abstract / Description
-
Extreme operating temperatures within the turbine section of jet engines require sophisticated methods of cooling and material protection. Thermal barrier coatings (TBCs) achieve this through a ceramic coating applied to a substrate material (nickel-based superalloy). Electron-beam physical vapor deposition (EB-PVD) is the industry standard coating used on jet engines. By tailoring the microstructure of an emerging deposition method, Plasma-spray physical vapor deposition (PS-PVD), similar...
Show moreExtreme operating temperatures within the turbine section of jet engines require sophisticated methods of cooling and material protection. Thermal barrier coatings (TBCs) achieve this through a ceramic coating applied to a substrate material (nickel-based superalloy). Electron-beam physical vapor deposition (EB-PVD) is the industry standard coating used on jet engines. By tailoring the microstructure of an emerging deposition method, Plasma-spray physical vapor deposition (PS-PVD), similar microstructures to that of EB-PVD coatings can be fabricated, allowing the benefits of strain tolerance to be obtained while improving coating deposition times. This work investigates the strain through depth of uncycled and cycled samples using these coating techniques with synchrotron X-ray diffraction (XRD). In the TGO, room temperature XRD measurements indicated samples of both deposition methods showed similar in-plane compressive stresses after 300 and 600 thermal cycles. In-situ XRD measurements indicated similar high-temperature in-plane and out-of-plane stress in the TGO and no spallation after 600 thermal cycles for both coatings. Tensile in-plane residual stresses were found in the YSZ uncycled PS-PVD samples, similar to APS coatings. PS-PVD samples showed in most cases, higher compressive residual in-plane stress at the YSZ/TGO interface. These results provide valuable insight for optimizing the PS-PVD processing parameters to obtain strain compliance similar to that of EB-PVD. Additionally, external cooling methods used for thermal management in jet engine turbines were investigated. In this work, an additively manufactured lattice structure providing transpiration cooling holes is designed and residual strains are measured within an AM transpiration cooling sample using XRD. Strains within the lattice structure were found to have greater variation than that of the AM solid wall. These results provide valuable insight into the viability of implementing an AM lattice structure in turbine blades for the use of transpiration cooling.
Show less - Date Issued
- 2019
- Identifier
- CFE0007844, ucf:52830
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007844