Download or read book A Study of Advanced Materials for Gas Turbine Coatings at Elevated Temperatures Using Selected Microstructures and Characteristic Environments for Syngas Combustion written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal barrier coatings (TBCs) that can be suitable for use in industrial gas turbine engines have been processed and compared with electron beam physical vapor deposition (EBPVD) microstructures for applications in advanced gas turbines that use coal-derived synthesis gas. Thermo-physical properties have been evaluated of the processed air plasma sprayed TBCs with standard APS-STD and vertically cracked APS-VC coatings samples up to 1300 C. Porosity of these selected coatings with related microstructural effects have been analyzed in this study. Wet and dry thermal cycling studies at 1125 C and spalling resistance thermal cycling studies to 1200 C have also been carried out. Type I and Type II hot corrosion tests were carried out to investigate the effects of microstructure variations and additions of alumina in YSZ top coats in multi-layered TBC structures. The thermal modeling of turbine blade has also been carried out that gives the capability to predict in-service performance temperature gradients. In addition to isothermal high temperature oxidation kinetics analysis in YSZ thermal barrier coatings of NiCoCrAlY bond coats with 0.25% Hf. This can affect the failure behavior depending on the control of the thermally grown oxide (TGO) growth at the interface. The TGO growth kinetics is seen to be parabolic and the activation energies correspond to interfacial growth kinetics that is controlled by the diffusion of O2 in Al2O3. The difference between oxidation behavior of the VC and STD structures are attributed to the effects of microstructure morphology and porosity on oxygen ingression into the zirconia and TGO layers. The isothermal oxidation resistance of the STD and VC microstructures is similar at temperatures up to 1200 C. However, the generally thicker TGO layer thicknesses and the slightly faster oxidation rates in the VC microstructures are attributed to the increased ingression of oxygen through the grain boundaries of the vertically cracked microstructures. The plasma sprayed TBC microstructure (VC and STD) with NiCoCrAlY-Hf bond coat are stable up to 1100 C. However, as with other TBC structures, a considerable amount of interdiffusion was observed in the different layers, although the TBC growth was self-limiting and parabolic. The addition of Hf to the VC microstructure appears to have some potential for the future development of robust TBCs with improved isothermal and service temperatures in advanced gas turbines.

Download or read book Coatings for High Temperature Structural Materials written by National Research Council and published by National Academies Press. This book was released on 1996-05-13 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book assesses the state of the art of coatings materials and processes for gas-turbine blades and vanes, determines potential applications of coatings in high-temperature environments, identifies needs for improved coatings in terms of performance enhancements, design considerations, and fabrication processes, assesses durability of advanced coating systems in expected service environments, and discusses the required inspection, repair, and maintenance methods. The promising areas for research and development of materials and processes for improved coating systems and the approaches to increased coating standardization are identified, with an emphasis on materials and processes with the potential for improved performance, quality, reproducibility, or manufacturing cost reduction.

Download or read book Effect of Simulated High Hydrogen Content Combustion Environments on Abradable Properties of Ceramic Turbine Coatings written by Madhura Basu Majumder and published by . This book was released on 2015 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Air plasma sprayed (APS) abradable coatings are used in the turbine hot section to reduce the stator-rotor gap, minimizing gas leakage. These coatings are designed to exhibit controlled removal of material in thin layers when the turbine blades sweep through the coating, which protects the mechanical integrity of the turbine blade. In an effort to lower CO2 emissions, high H2 content fuel is being explored. This change in chemical composition of the fuel may affect the microstructure, abradability and durability of the coatings at turbine operational temperatures. The presence of high water vapor in the combustion chamber leads to accelerated degradation of the sacrificial coating materials. In this work, zirconia based composite materials with a machinable phase and varied porosity have been used to study microstructural evolution, thermal and chemical stability of the phases and abradable characteristics of baseline coating systems in both humid and dry environments. Investigation of the mechanisms that control the removal of materials and performance of abradable coatings through thermo-mechanical tests will be discussed.

Download or read book Thermal and Environmental Barrier Coatings for Advanced Turbine Engine Applications written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ceramic thermal and environmental barrier coatings (T/EBCs) will play a crucial role in advanced gas turbine engine systems because of their ability to significantly increase engine operating temperatures and reduce cooling requirements, thus help achieve engine low emission and high efficiency goals. Advanced T/EBCs are being developed for the low emission SiC/SiC ceramic matrix composite (CMC) combustor applications by extending the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water vapor containing combustion environments. Low conductivity thermal barrier coatings (TBCs) are also being developed for metallic turbine airfoil and combustor applications, providing the component temperature capability up to 1650 C (3000 F). In this paper, ceramic coating development considerations and requirements for both the ceramic and metallic components will be described for engine high temperature and high-heat-flux applications. The underlying coating failure mechanisms and life prediction approaches will be discussed based on the simulated engine tests and fracture mechanics modeling results.Zhu, Dong-Ming and Miller, Robert A.Glenn Research CenterTHERMAL CONTROL COATINGS; GAS TURBINE ENGINES; CERAMIC COATINGS; CERAMIC MATRIX COMPOSITES; COMBUSTION CHAMBERS; ENGINE PARTS; CERAMICS; AIRFOILS; REFRACTORY MATERIALS; THERMAL CONDUCTIVITY; METALS; SILICON CARBIDES

Download or read book Advanced Materials and Coatings for Combustion Turbines written by V. P. Swaminathan and published by ASM International(OH). This book was released on 1994 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a broad spectrum of topics including requirements of alloys and coatings in gas turbines, advanced alloy development for hot-section components, application of aero-engine alloys to land-based gas turbines, directionally solidified and single crystal blade technology, and effects of service exposure on properties and degradation of turbine hot-section components.

Download or read book Advanced Coatings for Gas Turbine Materials written by Advanced coatings for gas turbine materials and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In situ generated Yb Si O environmental barrier coatings to protect non oxide silicon based ceramics in gas turbines Band 16 written by Mateus Lenz Leite and published by Cuvillier Verlag. This book was released on 2022-02-25 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: In face of an accelerating climate change, the reduction and substitution of fossil fuels is crucial to decarbonize energy production. Gas turbines can operate with versatile fuel sources like natural gas and future fuels such as hydrogen and ammonia. In a next future, thermal efficiencies above 65% are expected to be achieved by implementing non-oxide silicon-based (i.e. Si₃N₄, SiC and SiC/SiC) ceramic components. However, water vapor is one of the main combustion products, which leads to rapid corrosion due to the volatilization of the protective SiO₂ layer above 1200 °C. Hence, an in situ generated Yb₂Si₂O₇ double layered environmental barrier coating system composed of silazanes and the active fillers Yb2O3 and Si was processed at 1415 °C for 5 h in air to protect Si3N4, SiC and SiC/SiC from corrosion. The easy to apply coating system exhibits a dense microstructure with a thickness of up to 150 µm, besides an excellent adhesion strength (36.9 ± 6.2 MPa), hardness (6.9 ± 1.6 GPa) and scratch resistance (28 N). It remarkably overcomes over 15 thermal cycles between 1200 and 20 °C and shows almost no mass loss after harsh hot gas corrosion at 1200 °C for 200 h (pH2O = 0.15 atm, v = 100 m s⁻¹).

Download or read book Functionally Gradient Materials for Thermal Barrier Coatings in Advanced Gas Turbine Systems written by and published by . This book was released on 1995 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: New designs for advanced gas turbine engines for power production are required to have higher operating temperatures in order to increase efficiency. However, elevated temperatures will increase the magnitude and severity of environmental degradation of critical turbine components (e.g. combustor parts, turbine blades, etc.). To offset this problem, the usage of thermal barrier coatings (TBCs) has become popular by allowing an increase in maximum inlet temperatures for an operating engine. Although thermal barrier technology is over thirty years old, the principle failure mechanism is the spallation of the ceramic coating at or near the ceramic/bond coat interface. Therefore, it is desirable to develop a coating that combines the thermal barrier qualities of the ceramic layer and the corrosion protection by the metallic bond coat without the detrimental effects associated with the localization of the ceramic/metal interface to a single plane.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of MCrAlX coatings written by Pimin Zhang and published by Linköping University Electronic Press. This book was released on 2019-11-04 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: MCrAlY coatings (M=Ni and/or Co) are widely used for the protection of superalloy components against oxidation and hot corrosion in the hot sections of gas turbines. The drive for coating systems to bestow adequate oxidation and corrosion resistance upon the components becomes urgent as an inevitable result of the necessary improvement in engine combustion efficiency and service lifetime. Through the careful design of the composition, MCrAlY coating performance can be optimized to meet the needs under different service conditions and component materials, therefore, “MCrAlX”, with “X” stands for the minor alloying elements, is used to highlight the effect. In the present thesis, the performance of new MCrAlX coatings is investigated with respect to oxidation, hot corrosion and interactions between coating-superalloy substrates. Oxidation of MCrAlX coatings can be generally categorized into initial, steady and close-to-end stages. Coating performance can be affected by various factors at different stages, therefore, experiments were designed by targeting the oxidation stages. Investigation on the initial stage oxidation behavior of MCrAlY coatings with post-deposition surface treatments reveals the different growth mechanisms of alumina scales. Surface treatments significantly reduce the alumina growth rate by suppressing transient alumina development and aiding the early formation of ?-Al2O3, which improves the long-term oxidation performance of the coating. Similarly, the modification of minor alloy elements in MCrAlX coatings also serves the purpose. The oxidation behavior of new MCrAlX coatings was investigated at the steady oxidation stage, followed by the microstructure observation, thermodynamic and kinetic simulations. As an alternative reactive element addition of Y, Ce shows a negative effect on the formation of columnar alumina scales of high strain tolerance. In comparison, Fe or Ru addition shows no influence on alumina growth, rather than strengthening the phase stability in the coating and reducing the interdiffusion between coating-substrate through different mechanisms. As the oxidation proceeds to the close-to-end stage, a reliable criterion to estimate the capability of coating to form ?-Al2O3 is of great importance to accurately evaluate coating lifetime. A temperature-dependent critical Al-activity criterion was proposed to better predict the formation of a continuous ?-Al2O3 scale based on correction of elemental activity using thermodynamic database to replace the empirical Al-concentration based criterion. Severe interdiffusion occurs between coating-substrate during high temperature oxidation, accelerating the degradation of the system. Interdiffusion behavior of diffusion couples of superalloys-MCrAlX coatings were examined. It is highlighted that the recrystallization of superficial layer of the substrate contributes to the secondary reaction zone formation and element interdiffusion controls subsequent zone thickening. Study on Type I hot corrosion behavior of new MCrAlX coatings shows that the addition of Fe has no influence on basic fluxing reactions before severe Al depletion from the coating occurs. Instead, it boosts the “effective” Al supply of coating by shifting the equilibrium concentration of Al in the ? phase to a low Al level. Besides, the pre-mature coating degradation at the coating-substrate interface was due to the fast growth of corrosion products from substrate induced large local volume expansions, resulting in early coating spallation. MCrAlY ytbeläggningar (M=Ni och/eller Co) används ofta för att skydda komponenter tillverkade av superlegeringar mot oxidation samt högtemperaturskorrosion i de heta gasturbindelarna. Förbättrad förbränningseffektivitet och livslängd hos gasturbiner, gör att ytbeläggningssystemen måste besitta adekvata oxidations- och korrosionsmotstånd. Genom att omsorgsfullt utforma den kemiska sammansättningen hos MCrAlY ytbeläggningar kan deras prestanda optimeras för att möta kraven från olika driftförhållanden samt olika substratmaterial, därför används beteckningen "MCrAlX" för att belysa förändringar av den kemiska kompositionen, där "X" står för reaktiva legeringsämnen som tillsätts i mindre mängder. I denna avhandling undersöks prestandan hos en ny MCrAlX ytbeläggning med hänsyn till oxidation, högtemperaturskorrosion och interaktionen mellan ytbeläggningen och superlegeringssubstratet. Oxidation av MCrAlX ytbeläggningar kan generellt kategoriseras i tre faser; initiala, stabila och nära-slutet fasen. Ytbeläggningens prestanda kan påverkas av olika faktorer vid de olika faserna, därför utformades olika experiment för att undersöka de olika oxidationsfaserna. Undersökningen av den initiala fasen av oxidationsbeteendet hos MCrAlX ytbeläggningar som genomgått ytbehandlingar efter ytbeläggningsdeponeringen avslöjade olika tillväxtmekanismer hos aluminiumoxidskikten. Aluminiumoxidens tillväxthastighet reducerades signifikant av ytbehandlingarna, detta genom att undertrycka utvecklingen av övergående aluminiumoxid och bistå den tidiga tillväxten av ?-Al2O3, vilket förbättrar ytbeläggningens oxidationsprestanda långsiktigt. De reaktiva legeringsämnena som tillsätts i mindre mänger påverkar ytbeläggningens oxidationsprestanda på liknande sätt. Oxidationsbeteendet hos de nya MCrAlX ytbeläggningarna i den stabila fasen följdes av mikrostrukturundersökning, termodynamiska och kinetiska simuleringar. Det framkom att Ce visar en negativ effekt på bildandet av kolumnära aluminiumoxidskikt med hög töjningstolerans som alternativt reaktivt legeringsämne till Y. Jämförelsevis ger Fe- eller Ru-tillsatser ingen påverkan på aluminiumoxidtillväxten, förutom att det förstärker fasstabiliteten i ytbeläggningen samt genom olika mekanismer reducerar interdiffusionen mellan ytbeläggningen och substratet. När oxidationsprocessen kommit till nära-slutet fasen, är det viktigt att uppskatta kapaciteten hos en ytbeläggning att bilda ?-Al2O3, detta då det är ett tillförlitligt kriterium för att noggrant kunna utvärdera ytbeläggningens livslängd. Därför föreslogs ett temperaturberoende kriterium för kritisk Al-aktivitet för att bättre kunna förutsäga bildandet av ett kontinuerligt ?-Al2O3-skikt. Kriteriet baserades på korrigering av legeringsämnens aktivitet genom att använda en termodynamisk databas, detta för att ersätta det empiriska Al-koncentrations baserade kriteriet. Vid högtemperatursoxidation sker en omfattande interdiffusion mellan ytbeläggningen och substratet, vilket accelererar degraderingen av ytbeläggningssystemet. Därför har interdiffusionsbeteendet mellan superlegeringssubstratet och MCrAlX ytbeläggningen undersökts i denna avhandling. Det framkom att rekristallisationen av ytliga skikt av substratet bidrar till formationen av den sekundära reaktionszonen och att interdiffusion kontrollerar zonens efterföljande tjocklektillväxt. Undersökningen av Typ I högtemperaturskorrosionsbeteendet hos en ny MCrAlX ytbeläggning visar att legeringstillägg av Fe inte påverkar de grundläggande flödesreaktionerna innan en kritisk Al utarmning sker i ytbeläggningen. Istället stimulerar det tillförseln av Al genom att skifta jämviktskoncentrationen av Al i ? fasen till en låg nivå av Al. Det framkom också att den tidiga degraderingen av ytbeläggningen vid gränsskiktet mellan ytbeläggningen och substratet kommer av att den snabba tillväxten av korrosionsprodukter från substratet inducerade en stor lokal volymsutvidgning, vilket ledde till tidig ytbeläggningsspallation.

Download or read book Analytical Investigation of Thermal Barrier Coatings on Advanced Power Generation Gas Turbines written by and published by . This book was released on 1977 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coatings of High Temperature Materials written by H. H. Hausner and published by Springer. This book was released on 2013-11-11 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: The properties of materials depend on the characteristics of the bulk and on those of the surf ace. Any change in surface characteristics affects a wide variety of material properties. During the last few years the role of surface phenomena in metallurgy has been the subject of many studies. Surface energy, surface tension, the activity of surfaces, and related problems are under discussion in the western world * as well as in the eastern world. t The relation between volume and surface properties in metals and alloys has been investigated and is still under investigation. Materials are frequently exposed to environments which change their physical and chemical characteristics on account of a reaction going on between the material surface and the environment. The science and technology of surface preparation ro improve material properties have gained importance during the last decade in many parts of the world. Main efforts have been concentrated especially on the coating of material surfaces in connection with the exposure of these materials to space en vironment.

Download or read book Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. For future high performance engines, the development of advanced ceramic barrier coating systems will allow these coatings to be used to simultaneously increase engine operating temperature and reduce cooling requirements, thereby leading to significant improvements in engine power density and efficiency. In order to meet future engine performance and reliability requirements, the coating systems must be designed with increased high temperature stability, lower thermal conductivity, and improved thermal stress and erosion resistance. In this paper, ceramic coating design and testing considerations will be described for high temperature and high-heat-flux engine applications in hot corrosion and oxidation, erosion, and combustion water vapor environments. Further coating performance and life improvements will be expected by utilizing advanced coating architecture design, composition optimization, and improved processing techniques, in conjunction with modeling and design tools. Zhu, Dong-Ming and Miller, Robert A. Glenn Research Center NASA/TM-2004-213129, ARL-TR-3263, E-14622

Download or read book Functionally Graded Mullite Coatings for Gas Turbines written by Tushar Kulkarni and published by . This book was released on 2010 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The next generation of heat exchangers and gas turbines require high performance materials as they need to operate at higher temperatures for higher efficiency. SiC and Si 3 N 4 are promising candidates as they have excellent high temperature properties. However, when used in complex combustion environments found in gas-turbine applications, these materials have two major concerns; namely hot-corrosion and recession. It is well established that environmental barrier coatings (EBC) can be utilized to overcome these limitations. Although chemical vapor deposited (CVD) mullite (3Al 2 O 3 .2SiO 2 ) coatings developed before this study have shown promise in protecting Si-based substrates, there is concern that the silica content within the mullite coating itself might be susceptible to hot-corrosion and recession during long term exposure to corrosive atmospheres containing Na/V salts and water vapor. There is thus strong motivation to substantially reduce or even virtually eliminate the silica component from the surfaces of mullite coatings that are in direct contact with atmospheres containing corrosive oxides and steam. In this study, CVD has been used to deposit mullite coatings with potential promise to protect Si-based ceramics for high temperature applications. The composition of these functionally graded mullite coatings was varied from silica-rich close to the coating/substrate (SiC) interface for coefficient of thermal expansion match to alumina-rich towards the outer surface of the coating. In the process, the highest alumina-rich mullite ever reported has been deposited. The phase transformation and hot-corrosion behavior of the coatings was also investigated in this work. The coatings show immense potential to protect Si-based ceramics. It is expected that these coatings will have very broad impact by enabling gas turbines to operate at higher temperatures leading to improved fuel efficiency and reduced emissions.

Download or read book Environmental Degradation of Oxidation Resistant and Thermal Barrier Coatings for Fuel flexible Gas Turbine Applications written by Prabhakar Mohan and published by . This book was released on 2010 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of thermal barrier coatings (TBCs) has been undoubtedly the most critical advancement in materials technology for modern gas turbine engines. TBCs are widely used in gas turbine engines for both power-generation and propulsion applications. Metallic oxidation-resistant coatings (ORCs) are also widely employed as a stand-alone protective coating or bond coat for TBCs in many high-temperature applications. Among the widely studied durability issues in these high-temperature protective coatings, one critical challenge that received greater attention in recent years is their resistance to high-temperature degradation due to corrosive deposits arising from fuel impurities and CMAS (calcium-magnesium-alumino-silicate) sand deposits from air ingestion. The presence of vanadium, sulfur, phosphorus, sodium and calcium impurities in alternative fuels warrants a clear understanding of high-temperature materials degradation for the development of fuel-flexible gas turbine engines. Degradation due to CMAS is a critical problem for gas turbine components operating in a dust-laden environment. In this study, high-temperature degradation due to aggressive deposits such as V2O5, P2O5, Na2SO4, NaVO3, CaSO4 and a laboratory-synthesized CMAS sand for free-standing air plasma sprayed (APS) yttria stabilized zirconia (YSZ), the topcoat of the TBC system, and APS CoNiCrAlY, the bond coat of the TBC system or a stand-alone ORC, is examined. Phase transformations and microstructural development were examined by using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. This study demonstrated that the V2O5 melt degrades the APS YSZ through the formation of ZrV2O-- and YVO4 at temperatures below 747°C and above 747°C, respectively. Formation of YVO4 leads to the depletion of the Y2O3 stabilizer and the deleterious transformation of the YSZ to the monoclinic ZrO2 phase. The investigation on the YSZ degradation by Na2SO4 and a Na2SO4 + V2O5 mixture (50-50 mol. %) demonstrated that Na2SO4 itself did not degrade the YSZ, however, in the presence of V2O5, Na2SO4 formed vanadates such as NaVO3 that degraded the YSZ through YVO4 formation at temperature as low as 700°C. The APS YSZ was found to react with the P2O5 melt by forming ZrP2O-- at all temperatures. This interaction led to the depletion of ZrO2 in the YSZ (i.e., enrichment of Y2O3 in t'-YSZ) and promoted the formation of the fluorite-cubic ZrO2 phase. Above 1250°C, CMAS deposits were observed to readily infiltrate and significantly dissolve the YSZ coating via thermochemical interactions. Upon cooling, zirconia reprecipitated with a spherical morphology and a composition that depended on the local melt chemistry. The molten CMAS attack destabilized the YSZ through the detrimental phase transformation (t'[right arrow] t[right arrow]f + m). Free standing APS CoNiCrAlY was also prone to degradation by corrosive molten deposits. The V2O5 melt degraded the APS CoNiCrAlY through various reactions involving acidic dissolution of the protective oxide scale, which yielded substitutional-solid solution vanadates such as (Co, Ni)3(VO4)2 and (Cr, Al)VO4. The molten P2O5, on the other hand, was found to consume the bond coat constituents significantly via reactions that formed both Ni/Co rich phosphates and Cr/Al rich phosphates. Sulfate deposits such as Na2SO4, when tested in encapsulation, damaged the CoNiCrAlY by Type I acidic fluxing hot corrosion mechanisms at 1000°C that resulted in accelerated oxidation and sulfidation. The formation of a protective continuous Al2O3 oxide scale by preoxidation treatment significantly delayed the hot corrosion of CoNiCrAlY by sulfates. However, CoNiCrAlY in both as-sprayed and preoxidized condition suffered a significant damage by CaSO4 deposits via a basic fluxing mechanism that yielded CaCrO4 and CaAl2O4. The CMAS melt also dissolved the protective Al2O3 oxide scale developed on CoNiCrAlY by forming anorthite platelets and spinel oxides. Based on the detailed investigation on degradation of the APS YSZ and CoNiCrAlY by various corrosive deposits, an experimental attempt was carried out to mitigate the melt-induced deposit attack. Experimental results from this study demonstrate, for the first time, that an oxide overlay produced by electrophoretic deposition (EPD) can effectively perform as an environmental barrier overlay for APS TBCs. The EPD protective overlay has a uniform and easily-controllable thickness, uniformly distributed closed pores and tailored chemistry. The EPD Al2O3 and MgO overlays were successful in protecting the APS YSZ TBCs against CMAS attack and hot corrosion attack (e.g., sulfate and vanadate), respectively. Furnace thermal cyclic oxidation testing of overlay-modified TBCs on bond-coated superalloy also demonstrated the good adhesive durability of the EPD Al2O3 overlay.

Download or read book Advanced Technologies for Gas Turbines written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-04-19 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leadership in gas turbine technologies is of continuing importance as the value of gas turbine production is projected to grow substantially by 2030 and beyond. Power generation, aviation, and the oil and gas industries rely on advanced technologies for gas turbines. Market trends including world demographics, energy security and resilience, decarbonization, and customer profiles are rapidly changing and influencing the future of these industries and gas turbine technologies. Technology trends that define the technological environment in which gas turbine research and development will take place are also changing - including inexpensive, large scale computational capabilities, highly autonomous systems, additive manufacturing, and cybersecurity. It is important to evaluate how these changes influence the gas turbine industry and how to manage these changes moving forward. Advanced Technologies for Gas Turbines identifies high-priority opportunities for improving and creating advanced technologies that can be introduced into the design and manufacture of gas turbines to enhance their performance. The goals of this report are to assess the 2030 gas turbine global landscape via analysis of global leadership, market trends, and technology trends that impact gas turbine applications, develop a prioritization process, define high-priority research goals, identify high-priority research areas and topics to achieve the specified goals, and direct future research. Findings and recommendations from this report are important in guiding research within the gas turbine industry and advancing electrical power generation, commercial and military aviation, and oil and gas production.

Download or read book ADVANCED THERMAL BARRIER COATINGS FOR OPERATION IN HIGH HYDROGEN CONTENT FUELED GAS TURBINES written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Center for Thermal Spray Research (CTSR) at Stony Brook University in partnership with its industrial Consortium for Thermal Spray Technology is investigating science and technology related to advanced metallic alloy bond coats and ceramic thermal barrier coatings for applications in the hot section of gasified coal-based high hydrogen turbine power systems. In conjunction with our OEM partners (GE and Siemens) and through strategic partnership with Oak Ridge National Laboratory (ORNL) (materials degradation group and high temperature materials laboratory), a systems approach, considering all components of the TBC (multilayer ceramic top coat, metallic bond coat & superalloy substrate) is being taken during multi-layered coating design, process development and subsequent environmental testing. Recent advances in process science and advanced in situ thermal spray coating property measurement enabled within CTSR has been incorporated for full-field enhancement of coating and process reliability. The development of bond coat processing during this program explored various aspects of processing and microstructure and linked them to performance. The determination of the bond coat material was carried out during the initial stages of the program. Based on tests conducted both at Stony Brook University as well as those carried out at ORNL it was determined that the NiCoCrAlYHfSi (Amdry) bond coats had considerable benefits over NiCoCrAlY bond coats. Since the studies were also conducted at different cycling frequencies, thereby addressing an associated need for performance under different loading conditions, the Amdry bond coat was selected as the material of choice going forward in the program. With initial investigations focused on the fabrication of HVOF bond coats and the performance of TBC under furnace cycle tests, several processing strategies were developed. Two-layered HVOF bond coats were developed to render optimal balance of density and surface roughness and resulted in improved TBC lifetimes. Processing based approaches of identifying optimal processing regimes deploying advanced in-situ coating property measurements and in-flight diagnostic tools were used to develop process maps for bond coats. Having established a framework for the bond coat processing using the HVOF process, effort were channeled towards fabrication of APS and VPS bond coats with the same material composition. Comparative evaluation of the three deposition processes with regard to their microstrcuture, surface profiles and TBC performance were carried out and provided valuable insights into factors that require concurrent consideration for the development of bond coats for advanced TBC systems. Over the course of this program several advancements were made on the development of durable thermal barrier coatings. Process optimization techniques were utilized to identify processing regimes for both conventional YSZ as well as other TBC compositions such as Gadolinium Zirconate and other Co-doped materials. Measurement of critical properties for these formed the initial stages of the program to identify potential challenges in their implementation as part of a TBC system. High temperature thermal conductivity measurements as well as sintering behavior of both YSZ and GDZ coatings were evaluated as part of initial efforts to undersand the influence of processing on coating properties. By effectively linking fundamental coating properties of fracture toughness and elastic modulus to the cyclic performance of 6 DE-FE0004771, Final Report, April 2015: Stony Brook University coatings, a durability strategy for APS YSZ coatings was developed. In order to meet the goals of fabricating a multimaterial TBC system further research was carried out on the development of a gradient thermal conductivity model and the evaluation of sintering behavior of multimaterial coatings. Layer optimization for desired properties in the multimaterial TBC was achieved by a ...