Download or read book Thermal Conductivity and Elastic Modulus Evolution of Thermal Barrier Coatings Under High Heat Flux Conditions written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser high heat flux test approaches have been established to obtain critical properties of ceramic thermal barrier coatings (TBCs) under near-realistic temperature and thermal gradients that may he encountered in advanced engine systems. Thermal conductivity change kinetics of a thin ceramic coating were continuously monitored in real time at various test temperatures. A significant thermal conductivity increase was observed during the laser simulated engine heat flux tests. For a 0.25 mm thick ZrO2-8%Y2O3 coating system, the overall thermal conductivity increased from the initial value of 1.0 W/m-K to 1. 15 W/m-K, 1. 19 W/m-K and 1.5 W/m-K after 30 hour testing at surface temperatures of 990C, 1100C, and 1320C. respectively. Hardness and modulus gradients across a 1.5 mm thick TBC system were also determined as a function of laser testing time using the laser sintering/creep and micro-indentation techniques. The coating Knoop hardness values increased from the initial hardness value of 4 GPa to 5 GPa near the ceramic/bond coat interface, and to 7.5 GPa at the ceramic coating surface after 120 hour testing. The ceramic surface modulus increased from an initial value of about 70 GPa to a final value of 125 GPa. The increase in thermal conductivity and the evolution of significant hardness and modulus gradients in the TBC systems are attributed to sintering-induced micro-porosity gradients under the laser-imposed high thermal gradient conditions. The test techniques provide a viable means for obtaining coating data for use in design, development, stress modeling, and life prediction for various thermal barrier coating applications. Zhu, Dongming and Miller, Robert A. Glenn Research Center NASA/TM-1999-209069, NAS 1.15:209069, E-11625
Download or read book Thermal Conductivity and Elastic Modulus Evolution of Thermal Barrier Coatings Under High Heat Flux Conditions written by and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book THERMAL CONDUCTIVITY AND ELASTIC MODULUS EVOLUTION OF THERMAL BARRIER COATINGS UNDER HIGH HEAT FLUX CONDITIONS NASA TM 1999 209069 JU written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Conductivity 27 written by Hsin Wang and published by DEStech Publications, Inc. This book was released on 2005 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: In additional to traditional topics such as thermal insulation, instrumentation and standards, the conference highlighted research in carbon nanotubes, nanomaterials, novel thin films, thermoelectric and composites.
Download or read book Determination of Creep Behavior of Thermal Barrier Coatings Under Laser Imposed Temperature and Stress Gradients written by and published by . This book was released on 1997 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present study, a laser sintering/creep technique has been established to quantitatively determine the creep behavior of thermal barrier coatings under steady state high heat flux/high thermal gradient conditions. An approach is proposed to separate the strong influence of stress relaxation, based on the deduced strain rate changes with respect to time and temperature during testing. For a plasma sprayed zirconia-8wt.% yttria ceramic coating, a large primary creep strain and a low creep activation energy were observed. The significant primary creep stage and low apparent creep activation energy for the coating are attributed to stress induced mechanical sliding, and temperature and stress enhanced cation diffusion through the splat and grain boundaries. Possible creep mechanisms for the ceramic coating are also discussed. The elastic modulus evolution, the stress response and the total accumulated creep strain variation across the ceramic coating under laser imposed temperature and stress conditions are simulated using a finite difference approach. The modeled creep response is consistent with experimental observations.
Download or read book Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems written by and published by . This book was released on 2000 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady State Laser Heat Flux Approach 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: The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications. Zhu, Dong-Ming and Miller, Robert A. Glenn Research Center NASA/TM-2004-213040, E-14474, ARL-TR-3262
Download or read book Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady State Laser Heat Flux Approach written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.
Download or read book Progress in Thermal Barrier Coatings written by ACerS (American Ceramics Society, The) and published by John Wiley & Sons. This book was released on 2009-06-15 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edition of the Progress in Ceramic Technology series compiles articles published on thermal barrier coatings (TBCs) by The American Ceramic Society (ACerS). It collects in one resource the current research papers on materials-related aspects of thermal barrier coatings and associated technologies. Logically organized and carefully selected, the papers in this edition divide into six categories: Applications Material Improvements and Novel Compositions Developments in Processing Mechanical Properties Thermal Properties Citations follow each title in the table of contents, making this a key resource for professionals and academia.
Download or read book Development of Advanced Low Conductivity Thermal Barrier Coatings 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 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced multi-component, low conductivity oxide thermal barrier coatings have been developed using an approach that emphasizes real-time monitoring of thermal conductivity under conditions that are engine-like in terms of temperatures and heat fluxes. This is in contrast to the traditional approach where coatings are initially optimized in terms of furnace and burner rig durability with subsequent measurement in the as-processed or furnace-sintered condition. The present work establishes a laser high-heat-flux test as the basis for evaluating advanced plasma-sprayed and electron beam-physical vapor deposited (EB-PVD) thermal barrier coatings under the NASA Ultra-Efficient Engine Technology (UEET) Program. The candidate coating materials for this program are novel thermal barrier coatings that are found to have significantly reduced thermal conductivities and improved thermal stability due to an oxide-defect-cluster design. Critical issues for designing advanced low conductivity coatings with improved coating durability are also discussed. Zhu, Dong-Ming and Miller, Robert A. Glenn Research Center NASA/TM-2004-212961, E-14433, ARL-TR-3259
Download or read book 25th Annual Conference on Composites Advanced Ceramics Materials and Structures B Volume 22 Issue 4 written by Mrityunjay Singh and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.
Download or read book 24th Annual Conference on Composites Advanced Ceramics Materials and Structures B Volume 21 Issue 4 written by Todd Jessen and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 713 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.
Download or read book Thermal Conductivity of EB PVD Thermal Barrier Coatings Evaluated by a Steady State Laser Heat Flux Technique written by and published by . This book was released on 2000 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermal conductivity of electron beam-physical vapor deposited (EB-PVD) Zr02-8wt%Y2O3 thermal barrier coatings was determined by a steady-state heat flux laser technique. Thermal conductivity change kinetics of the EB-PVD ceramic coatings were also obtained in real time, at high temperatures, under the laser high heat flux, long term test conditions. The thermal conductivity increase due to micro-pore sintering and the decrease due to coating micro-delaminations in the EB-PVD coatings were evaluated for grooved and non-grooved EB-PVD coating systems under isothermal and thermal cycling conditions. The coating failure modes under the high heat flux test conditions were also investigated. The test technique provides a viable means for obtaining coating thermal conductivity data for use in design, development, and life prediction for engine applications.
Download or read book Thermal Barrier Coatings written by Hongbo Guo and published by Woodhead Publishing. This book was released on 2023-01-18 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal Barrier Coatings, Second Edition plays a critical role in counteracting the effects of corrosion and degradation of exposed materials in high-temperature environments such as gas turbine and aero-engines. This updated edition reviews recent advances in the processing and performance of thermal barrier coatings, as well as their failure mechanisms. Novel technologies for the manufacturing of thermal barrier coatings (TBCs) such as plasma spray-physical vapor deposition and suspension plasma spray, are covered, as well as severe degradation of TBCs caused by CMAS attack. In addition to discussions of new materials and technologies, an outlook about next generation TBCs, including T/EBCs is discussed.This edition will provide the fundamental science and engineering of thermal barrier coatings for researchers in the field of TBCs, as well as students looking for a tutorial. Includes coverage of emerging materials, such as rare-earth doped ceramics Presents the latest on plasma spray-physical vapor deposition and suspension (solution precursor) Discusses the degradation of TBCs caused by CMAS attack and its protection Looks at thermally environmental barrier coatings, interdiffusion and diffusion barrier
Download or read book Thermal Barrier Coatings for Advanced Gas Turbine and Diesel Engines written by and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Conductivity of Ceramic Thermal Barrier and Environmental Barrier Coating Materials written by and published by . This book was released on 2001 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 26th Annual Conference on Composites Advanced Ceramics Materials and Structures B Volume 23 Issue 4 written by Hua-Tay Lin and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 901 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.
