Download or read book Atomistic and Finite Element Modeling of Zirconia for Thermal Barrier Coating Applications written by Yi Zhang and published by . This book was released on 2014 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zirconia (ZrO2) is an important ceramic material with a broad range of applications. Due to its high melting temperature, low thermal conductivity, and high-temperature stability, zirconia based ceramics have been widely used for thermal barrier coatings (TBCs). When TBC is exposed to thermal cycling during real applications, the TBC may fail due to several mechanisms: (1) phase transformation into yttrium-rich and yttrium-depleted regions, When the yttrium-rich region produces pure zirconia domains that transform between monoclinic and tetragonal phases upon thermal cycling; and (2) cracking of the coating due to stress induced by erosion. The mechanism of erosion involves gross plastic damage within the TBC, often leading to ceramic loss and/or cracks down to the bond coat. The damage mechanisms are related to service parameters, including TBC material properties, temperature, velocity, particle size, and impact angle. The goal of this thesis is to understand the structural and mechanical properties of the thermal barrier coating material, thus increasing the service lifetime of gas turbine engines. To this end, it is critical to study the fundamental properties and potential failure mechanisms of zirconia. This thesis is focused on investigating the structural and mechanical properties of zirconia. There are mainly two parts studied in this paper, (1) ab initio calculations of thermodynamic properties of both monoclinic and tetragonal phase zirconia, and monoclinic-to-tetragonal phase transformation, and (2) image-based finite element simulation of the indentation process of yttria-stabilized zirconia. In the first part of this study, the structural properties, including lattice parameter, band structure, density of state, as well as elastic constants for both monoclinic and tetragonal zirconia have been computed. The pressure-dependent phase transition between tetragonal (t-ZrO2) and cubic zirconia (c-ZrO2) has been calculated using the density function theory (DFT) method. Phase transformation is defined by the band structure and tetragonal distortion changes. The results predict a transition from a monoclinic structure to a fluorite-type cubic structure at the pressure of 37 GPa. Thermodynamic property calculations of monoclinic zirconia (m-ZrO2) were also carried out. Temperature-dependent heat capacity, entropy, free energy, Debye temperature of monoclinic zirconia, from 0 to 1000 K, were computed, and they compared well with those reported in the literature. Moreover, the atomistic simulations correctly predicted the phase transitions of m-ZrO2 under compressive pressures ranging from 0 to 70 GPa. The phase transition pressures of monoclinic to orthorhombic I (3 GPa), orthorhombic I to orthorhombic II (8 GPa), orthorhombic II to tetragonal (37 GPa), and stable tetragonal phases (37-60 GPa) are in excellent agreement with experimental data. In the second part of this study, the mechanical response of yttria-stabilized zirconia under Rockwell superficial indentation was studied. The microstructure image based finite element method was used to validate the model using a composite cermet material. Then, the finite element model of Rockwell indentation of yttria-stabilized zirconia was developed, and the result was compared with experimental hardness data.

Download or read book MODELING OF CHEMICAL VAPOR DEPOSITED ZIRCONIA FOR THERMAL BARRIER AND ENVIRONMENTAL BARRIER COATINGS written by T. L. Starr and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal and environmental barrier coatings are important components of current and future energy systems. Such coatings--applied to hot, metallic surfaces in combustors, heat exchanger and turbines--increase the allowable operating temperature and increase the efficiency of the energy system. Because of its low thermal conductivity and high thermal expansion yttria-stabilized zirconia (YSZ) is the material of choice for protection of structural components in many high temperature applications. Current coating application methods have their drawbacks, however. Air plasma spray (APS) is a relatively low-cost process and is suitable for large and relatively complex shapes. It is difficult to produce uniform, relatively thin coatings with this process, however, and the coatings do not exhibit the columnar microstructure that is needed for reliable, long-term performance. The electron-beam physical vapor deposition (EB-PVD) process does produce the desirable microstructure, however, the capital cost of these systems is very high and the line-of-sight nature of the process limits coating uniformity and the ability to coat large and complex shapes. The chemical vapor deposition (CVD) process also produces the desirable columnar microstructure and--under proper conditions--can produce uniform coatings over complex shapes. The overall goal of this project--a joint effort of the University of Louisville and Oak Ridge National Laboratory (ORNL)--is to develop the YSZ CVD process for application of thermal barrier coatings for fossil energy systems. Last year's report described our initial efforts toward developing a model for the process and for ORNL's bench-scale reactor. This model provides an understanding of the transport and kinetics phenomena that control the deposition process and ultimately will provide a tool for fullscale reactor design and optimization. Our overall research approach is: validate the 3-D computer model using experimental results at ORNL, use the model to identify and evaluate potential process improvements and design a reactor for large and complex substrates. This report describes the modeling effort at the University of Louisville which supports the experimental work at ORNL.

Download or read book Phase Stability of Yttria stabilized Zirconia for Thermal Barrier Coating Applications written by Vanni Lughi and published by . This book was released on 2005 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Modified Zirconia Thermal Barrier Coatings for Gas Turbine Applications written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2566 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metallurgical and Ceramic Protective Coatings written by K.H. Stern and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface engineering is an increasingly important field and consequently those involved need to be aware of the vast range of technologies available to modify surfaces. This text provides an up-to-date, authoritative exposition of the major condensed phase methods used for producing metallurgical and ceramic coatings. Each method is discussed thoroughly by an expert in that field. In each chapter the principle of the method, its range of applications and technical aspects involved are described. The book not only informs the reader about established technologies familiar only to specialists, but also details activity on the frontier of coating technology providing an insight into those potential technologies not yet fully developed but which should emerge in the near future.

Download or read book Ceramic Materials and Components for Engines written by Jürgen G. Heinrich and published by John Wiley & Sons. This book was released on 2008-11-21 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several ceramic parts have already proven their suitability for serial application in automobile engines in very impressive ways, especially in Japan, the USA and in Germany. However, there is still a lack of economical quality assurance concepts. Recently, a new generation of ceramic components, for the use in energy, transportation and environment systems, has been developed. The efforts are more and more system oriented in this field. The only possibility to manage this complex issue in the future will be interdisciplinary cooperation. Chemists, physicists, material scientists, process engineers, mechanical engineers and engine manufacturers will have to cooperate in a more intensive way than ever before. The R&D activities are still concentrating on gas turbines and reciprocating engines, but also on brakes, bearings, fuel cells, batteries, filters, membranes, sensors and actuators as well as on shaping and cutting tools for low expense machining of ceramic components. This book summarizes the scientific papers of the 7th International Symposium "Ceramic Materials and Components for Engines". Some of the most fascinating new applications of ceramic meterials in energy, transportation and environment systems are presented. The proceedings shall lead to new ideas for interdisciplinary activities in the future.

Download or read book Classical And Quantum Dynamics In Condensed Phase Simulations Proceedings Of The International School Of Physics written by Bruce J Berne and published by World Scientific. This book was released on 1998-06-17 with total page 881 pages. Available in PDF, EPUB and Kindle. Book excerpt: The school held at Villa Marigola, Lerici, Italy, in July 1997 was very much an educational experiment aimed not just at teaching a new generation of students the latest developments in computer simulation methods and theory, but also at bringing together researchers from the condensed matter computer simulation community, the biophysical chemistry community and the quantum dynamics community to confront the shared problem: the development of methods to treat the dynamics of quantum condensed phase systems.This volume collects the lectures delivered there. Due to the focus of the school, the contributions divide along natural lines into two broad groups: (1) the most sophisticated forms of the art of computer simulation, including biased phase space sampling schemes, methods which address the multiplicity of time scales in condensed phase problems, and static equilibrium methods for treating quantum systems; (2) the contributions on quantum dynamics, including methods for mixing quantum and classical dynamics in condensed phase simulations and methods capable of treating all degrees of freedom quantum-mechanically.

Download or read book Atomic Layer Deposition for Semiconductors written by Cheol Seong Hwang and published by Springer Science & Business Media. This book was released on 2013-10-18 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering thorough coverage of atomic layer deposition (ALD), this book moves from basic chemistry of ALD and modeling of processes to examine ALD in memory, logic devices and machines. Reviews history, operating principles and ALD processes for each device.

Download or read book Environmental Barrier Coatings written by Kang N. Lee and published by MDPI. This book was released on 2020-12-29 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global increase in air travel will require commercial vehicles to be more efficient than ever before. Advanced engine hot section materials are a key technology required to keep fuel consumption and emission to a minimum in next-generation gas turbines. Ceramic matrix composites (CMCs) are the most promising material to revolutionize gas turbine hot section materials technology because of their excellent high‐temperature properties. Rapid surface recession due to volatilization by water vapor is the Achilles heel of CMCs. Environmental barrier coatings (EBCs) is an enabling technology for CMCs, since it protects CMCs from water vapor. The first CMC component entered into service in 2016 in a commercial engine, and more CMC components are scheduled to follow within the next few years. One of the most difficult challenges to CMC components is EBC durability, because failure of EBC leads to a rapid reduction in CMC component life. Key contributors to EBC failure include recession, oxidation, degradation by calcium‐aluminum‐magnesium silicates (CMAS) deposits, thermal and thermo‐mechanical strains, particle erosion, and foreign object damage (FOD). Novel EBC chemistries, creative EBC designs, and robust processes are required to meet EBC durability challenges. Engine-relevant testing, characterization, and lifing methods need to be developed to improve EBC reliability. The aim of this Special Issue is to present recent advances in EBC technology to address these issues. In particular, topics of interest include but are not limited to the following: • Novel EBC chemistries and designs; • Processing including plasma spray, suspension plasma spray, solution precursor plasma spray, slurry process, PS-PVD, EB-PVD, and CVD; • Testing, characterization, and modeling; • Lifing.

Download or read book The Science and Engineering of Thermal Spray Coatings written by Lech Pawlowski and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated and revised version builds on the success of the first edition featuring new discoveries in powder technology, spraying techniques, new coatings applications and testing techniques for coatings -- Many new spray techniques are considered that did not exist when the first edition was published! The book begins with coverage of materials used, pre-spray treatment, and the techniques used. It then leads into the physics and chemistry of spraying and discusses coatings build-up. Characterization methods and the properties of the applied coatings are presented, and the book concludes with a lengthy chapters on thermal spray applications covers such areas as the aeronautics and space, automobiles, ceramics, chemicals, civil engineering, decorative coatings, electronics, energy generation and transport, iron and steel, medicine, mining and the nuclear industries.

Download or read book Classic and Advanced Ceramics written by Robert B. Heimann and published by John Wiley & Sons. This book was released on 2010-04-16 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the author's lectures to graduate students of geosciences, physics, chemistry and materials science, this didactic handbook covers basic aspects of ceramics such as composition and structure as well as such advanced topics as achieving specific functionalities by choosing the right materials. The focus lies on the thermal transformation processes of natural raw materials to arrive at traditional structural ceramics and on the general physical principles of advanced functional ceramics. The book thus provides practice-oriented information to readers in research, development and engineering on how to understand, make and improve ceramics and derived products, while also serving as a rapid reference for the practitioner. The choice of topics and style of presentation make it equally useful for chemists, materials scientists, engineers and mineralogists.

Download or read book Recent Advances in Technology Research and Education written by Dumitru Luca and published by Springer. This book was released on 2017-09-08 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected contributions to the 16th International Conference on Global Research and Education Inter-Academia 2017 hosted by Alexandru Ioan Cuza University of Iași, Romania from 25 to 28 September 2017. It is the third volume in the series, following the editions from 2015 and 2016. Fundamental and applied research in natural sciences have led to crucial developments in the ongoing 4th global industrial revolution, in the course of which information technology has become deeply embedded in industrial management, research and innovation – and just as deeply in education and everyday life. Materials science and nanotechnology, plasma and solid state physics, photonics, electrical and electronic engineering, robotics and metrology, signal processing, e-learning, intelligent and soft computing have long since been central research priorities for the Inter-Academia Community (I-AC) – a body comprising 14 universities and research institutes from Japan and Central/East-European countries that agreed, in 2002, to coordinate their research and education programs so as to better address today’s challenges. The book is intended for use in academic, government, and industrial R&D departments as a reference tool in research and technology education. The 42 peer-reviewed papers were written by more than 119 leading scientists from 14 countries, most of them affiliated to the I-AC.

Download or read book Functionally Graded Materials written by Y. Miyamoto and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven years have elapsed since Dr. Renee Ford, editor-in-chief of Materials Technology, first suggested to me to publish a book on Functionally Graded Materials (FGMs). She said that the FGM concept, then largely unknown outside of Japan and a relatively few laboratories elsewhere, would be of great interest to everyone working in the materials field because of its potentially universal applicability. There was no book about FGMs in English at that time, although the number of research papers, review articles, and FGM conference proceedings had been increasing yearly. We discussed what the book should cover, and decided it should present a comprehensive description from basic theory to the most recent applications of FGMs. This would make it useful both as an introduction to FGMs for those simply curious about what this new materials field was all about, and also as a textbook for researchers, engineers, and graduate students in various material fields. The FGM Forum in Japan generously offered to support this publication program. is very difficult for an individual author to write a book that Because it covers such a wide range of various aspects of many different materials, I invited more than 30 eminent materials scientists throughout the world, who were associated with FGM research, to contribute selected topics. I also asked several leading researchers in this field to edit selected chapters: Dr. Barry H. Rabin, then at the U. S.

Download or read book Functionally Graded Materials written by Rasheedat Modupe Mahamood and published by Springer. This book was released on 2017-02-14 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the concept of functionally graded materials as well as their use and different fabrication processes. The authors describe the use of additive manufacturing technology for the production of very complex parts directly from the three dimension computer aided design of the part by adding material layer after layer. A case study is also presented in the book on the experimental analysis of functionally graded material using laser metal deposition process.