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 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 23nd Annual Conference on Composites Advanced Ceramics Materials and Structures A Volume 20 Issue 3 written by Ersan Ustundag and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 655 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 Progress in Thermal Barrier Coatings written by ACerS (American Ceramics Society, The) and published by John Wiley & Sons. This book was released on 2009-07-15 with total page 628 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 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 Spray 2004 written by and published by ASM International. This book was released on 2004-01-01 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Ceramic Coatings and Interfaces written by Dongming Zhu and published by John Wiley & Sons. This book was released on 2009-09-29 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in coating development, processing, microstructure and property characterization, and life prediction are included in this book, which came from the proceedings of the 30th International Conference on Advanced Ceramics and Composites, January 22-27, 2006, Cocoa Beach, Florida. Organized and sponsored by The American Ceramic Society and The American Ceramic Society's Engineering Ceramics Division in conjunction with the Nuclear and Environmental Technology Division.. Integrated structural, environmental properties and functionality through advanced coating processing and structural design are emphasized in this book.
Download or read book Elevated Temperature Coatings Science and Technology III written by Janet M. Hampikian and published by Minerals, Metals, & Materials Society. This book was released on 1999 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This symposium held at the 1999 TMS Annual Meeting & Exhibition details technologies in the processing and characterization of high-temperature coatings with regard to properties, techniques, and applications. Specific topics include thermal barrier coatings, ceramic coatings, composite coatings, tribological coatings, coatings for optical applications, repair and removal of coatings, oxidation resistant coatings, metallic coatings, characterization techniques for coatings, and high-temperature intermetallic coatings.
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 Fatigue and Fracture Behavior of Ceramic Thermal Barrier Coatings written by and published by . This book was released on 2001 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cyclic Failure Mechanisms of Thermal and Environmental Barrier Coating Systems Under Thermal Gradient Test Conditions written by and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Thermal High Cycle and Low Cycle Fatigue Mechanisms of Thick Thermal Barrier Coatings written by and published by . This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Durable Surfaces written by D. R. Mumm and published by . This book was released on 2001 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents ten chapters on the science and engineering of durable surfaces. The first section focusses on various types of surfaces and advanced coating processes, while the second part concentrates particularly on thermal barrier coatings. The book covers both, in-depth state-of-the-art reviews as well as cutting-edge new information emerging from ongoing research:
Download or read book Thermal Gradient Cyclic Behavior of a Thermal Environmental Barrier Coating System on SiC SiC Ceramic Matrix Composites written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-27 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal barrier and environmental barrier coatings (TBCs and EBCs) will play a crucial role in future advanced gas turbine engines because of their ability to significantly extend the temperature capability of the ceramic matrix composite (CMC) engine components in harsh combustion environments. In order to develop high performance, robust coating systems for effective thermal and environmental protection of the engine components, appropriate test approaches for evaluating the critical coating properties must be established. In this paper, a laser high-heat-flux, thermal gradient approach for testing the coatings will be described. Thermal cyclic behavior of plasma-sprayed coating systems, consisting of ZrO2-8wt%Y2O3 thermal barrier and NASA Enabling Propulsion Materials (EPM) Program developed mullite+BSAS/Si type environmental barrier coatings on SiC/SiC ceramic matrix composites, was investigated under thermal gradients using the laser heat-flux rig in conjunction with the furnace thermal cyclic tests in water-vapor environments. The coating sintering and interface damage were assessed by monitoring the real-time thermal conductivity changes during the laser heat-flux tests and by examining the microstructural changes after the tests. The coating failure mechanisms are discussed based on the cyclic test results and are correlated to the sintering, creep, and thermal stress behavior under simulated engine temperature and heat flux conditions. Zhu, Dongming and Lee, Kang N. and Miller, Robert A. Glenn Research Center NASA/TM-2002-211593, NAS 1.15:211593, E-13377, GT-2002-30632...
Download or read book Creep and Fracture in High Temperature Components written by European Creep Collaborative Committee and published by DEStech Publications, Inc. This book was released on 2005 with total page 1136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides information from around the world on creep in multiple high-temperature metals, alloys, and advanced materials.
Download or read book Thermal Gradient Cyclic Behavior of a Thermal Environmental Barrier Coating System on SiC SiC Ceramic Matrix Composites written by and published by . This book was released on 2002 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
