Download or read book Study of Bond Coating Pre oxidation Heat Treatments for High Temperature Thin Film Sensors in Gas Turbine Engine Applications written by Philipp Puetz and published by . This book was released on 2010 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Coatings written by Sudhangshu Bose and published by Elsevier. This book was released on 2011-04-01 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Coatings demonstrates how to counteract the thermal effects of the rapid corrosion and degradation of exposed materials and equipment that can occur under high operating temperatures. This is the first true practical guide on the use of thermally-protective coatings for high-temperature applications, including the latest developments in materials used for protective coatings. It covers the make-up and behavior of such materials under thermal stress and the methods used for applying them to specific types of substrates, as well as invaluable advice on inspection and repair of existing thermal coatings.With his long experience in the aerospace gas turbine industry, the author has compiled the very latest in coating materials and coating technologies, as well as hard-to-find guidance on maintaining and repairing thermal coatings, including appropriate inspection protocols. The book will be supplemented with the latest reference information and additional support for finding more application-type and industry-type coatings specifications and uses, with help for the reader in finding more detailed information on a specific type of coating or a specific type of use.· Offers overview of the underlying fundamental concepts of thermally-protective coatings, including thermodynamics, energy kinetics, crystallography, and equilibrium phases· Covers essential chemistry and physics of underlying substrates, including steels, nickel-iron alloys, nickel-cobalt alloys, and titanium alloys· Provides detailed guidance on wide variety of coating types, including those used against high temperature corrosion and oxidative degradation, as well as thermal barrier coatings

Download or read book Oxidation behaviour of MCrAlX coatings written by Pimin Zhang and published by Linköping University Electronic Press. This book was released on 2018-02-12 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: MCrAlY coatings (M=Ni and/or Co) have been widely used for the protection of superalloy components against oxidation and hot corrosion in the hot sections of gas turbines. The drive to improve engine combustion efficiency while reducing emissions by increasing the operation temperature brings a big challenge for coating design. As a result, the need for improvement of MCrAlY coatings for better oxidation resistance is essential. Formation of a stable, dense, continuous, and slow-growing ?-Al2O3 layer, on the MCrAlY coating surface, is the key to oxidation protection, since the protective ?-Al2O3 scale offers superior oxidation resistance due to its lower oxygen-diffusion rate as compared with other oxides. The ability of a MCrAlY coating to form and maintain such a protective scale depends on the coating composition and microstructure, and can be improved through optimization of deposition parameters, modification of coating surface conditions, and so on. Part of this thesis work focuses on studying the effect of post-deposition surface treatments on the oxidation behavior of MCrAlX coatings (X can be yttrium and/or other minor alloying elements). The aim is to gain fundamental understanding of alumina scale evolution during oxidation which is important for achieving improved oxidation resistance of MCrAlX coatings. Oxide scale formed on coatings at initial oxidation stage and the effect of surface treatment were investigated by a multi-approach study combining photo-stimulated luminescence, microstructural observation and weight gain. Results showed that both mechanically polished and shot-peened coatings exhibited superior performance due to rapid formation of ?-Al2O3 fully covering the coating and suppressing growth of transient alumina, assisted by the high density of ?-Al2O3 nuclei on surface treatment induced defects. The early development of a two-layer alumina scale, consisting of an inward-grown inner ?-Al2O3 layer and an outer layer transformed from outward-grown transient alumina, resulted in a higher oxide growth rate of the as-sprayed coating. The positive effect of the surface treatments on retarding oxide scale growth and suppressing formation of spinel was also observed in oxidation test up to 1000 hrs. 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, which is the aim of the other part of the thesis work. Survey of published results on a number of binary Ni-Al and ternary Ni-Cr-Al, Ni-Al-Si systems shows that the empirical Al-concentration based criterion is inadequate to properly predict the formation of a continuous ?-Al2O3 scale. On the other hand, correlating the corresponding Al-activity data, calculated from measured chemical compositions using the Thermo-Calc software, to the experimental oxidation results has revealed a temperature dependent, critical Al-activity value for forming continuous ?-Al2O3 scale. To validate the criterion, long-term oxidation tests were performed on five MCrAlX coatings with varying compositions and the implementation of the Al-activity based criterion on these coatings successfully predicted ?-Al2O3 formation, showing a good agreement with experiment results.

Download or read book Coatings for High Temperature Environments written by Amirhossein Pakseresht and published by Springer Nature. This book was released on 2023-12-05 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the recent trends in high-temperature coatings that are used to provide oxidation and wear resistance to metallic/ceramic components in extreme environments. Ceramics, intermetallics, organosilicon polymers, cermets, and other materials with great thermal stability have long been recognized for these applications. This book introduces the state of the art in coating materials and processes for high-temperature environments and identifies areas for improvement in materials selection, performance upgrades, design considerations, and manufacturing methods. The book covers a variety of high-temperature coatings prepared through various synthesis processes such as thermal spraying, physical vapor deposition, electrodeposition, and sol–gel methods. It covers corrosion/oxidation, phase stability, and thermal and mechanical behavior of high-temperature coating materials having greater thermal stability. With contributions from international researchers active in the field, this edited book features the most recent and up-to-date literature references for a broad readership consisting of academic and industrial professionals. It is suitable for graduate students as well as scientists and engineers working in the area of anti-corrosion and anti-wear resistant high-temperature coatings for industrial applications.

Download or read book High temperature Oxidation resistant Coatings written by National Research Council (U.S.). Committee on Coatings and published by National Academies. This book was released on 1970 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Protective Coatings for Aero Engine Gas Turbine Components written by J-P. A. Immarigeon and published by . This book was released on 1986 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminide coatings have been widely used in the aircraft industries for the protection of gas turbine engine hot section components against oxidation and/or hot corrosion. This paper considers modes of coating degradation under conditions of cyclic oxidation, hot corrosion and corrosion-erosion interactions during service as well as the effects of interdiffusion between coating and substrate alloys either during service or coating application. It also discusses means of improving existing coatings as well as advanced coating systems currently under development. In assessing coating performance, consideration must be given to the influence coatings may have on substrate properties such as mechanical strength, resistance to creep and resistance to mechanical and thermal fatigue. Finally it is stressed that proven performance for a given coating/substrate combination is no guarantee that no deleterious reaction will occur, when the same coating is used with a different substrate alloy. Therefore, coating substitution requires requalification. Keywords: Aircraft engines; Protective coatings.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Coating Study to Reduce Contact Stress Damage of Ceramics written by J. Schienle and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon nitride (Si3N4) and silicon carbide (SiC) ceramics are susceptible to contact stress damage at ceramic component interfaces in gas turbine engines. The objective of this research program was to develop adherent coating compositions and procedures that will improve contact-stress damage resistance of Si3N4 and SiC. Yttria (Y2O3) stabilized zirconia (ZrO2) coatings were applied by electron beam - physical vapor deposition (EB-PVD) to three substrate materials: reaction bonded Si3N4 (RBSN), sintered Si3N4, and sintered SiC (SSC). Several controlled substrate pretreatments (both mechanical and chemical) were used to aid in obtaining a better understanding of the mechanisms of coating adherence. Each coating/substrate system was evaluated for coating adherence before and after oxidation exposure. The coating/substrate interfaces were evaluated for microstructural characteristics. Based on the results, pretreatment and coating approaches projected to improve coating adherence were selected. Specimens were prepared to evaluate the coating adherence before and after oxidation exposure. The systems exhibiting the best coating adherence after oxidation exposure were identified. Additional speci- mens for each of these systems were prepared for analysis of the coating thermal spall resistance, friction, and contact damage resistance. The friction and contact damage resistance of uncoated RBSN, SSN, and SSC were also evaluated.

Download or read book High Temperature Surface Engineering written by J. Nicholls and published by CRC Press. This book was released on 2020-01-31 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last forty years a wide range of surface coatings have been developed to address the surface stability and thermal insulation of materials used in the gas turbine section of aero, industrial and land-based power generation equipment. High Temperature Surface Engineering, the Proceedings of the Sixth International Conference in the Series ‘Engineering the Surfaces’, reviews the surfacing technologies appropriate to oxidation, corrosion and thermal protection. Factors which underpin their choice for any given application are discussed in the proceedings. This highlights the importance of developing representative mechanical and physical test methods to elucidate coating degradation modes as an aid to establishing coating systems with improved engineering performance. During the organisation of the conference and in the compiling of this book we have been privileged to work with many of the leading specialists in the field of High Temperature Surface Engineering and it is our hope that this book will be a valuable reference guide for Engineers and Material Scientists.

Download or read book Development of Conventional and Nanocrystalline Bond Coats by Cold Gas Dynamic Spraying for Aerospace Thermal Barrier Coatings written by Patrick Richer and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbine engines are considered to be among the most hostile operating environments for conventional material systems. Increasing demands for higher engine performance and durability of components have led to the development of thermal barrier coating (TBC) systems. Typical TBC systems consist of two coating layers: an insulating ceramic top coat for thermal protection and an underlying metallic bond coat for improved adhesion of the top coat and better chemical protection against high temperature oxidation and hot corrosion. However, current use of these coating systems is limited due to their premature failure which is associated to cracking and delaminating of the ceramic top coat. It is generally accepted that the primary mechanism responsible for TBC failure is attributed to oxidation of the bond coat which results in the formation of an oxide scale at the interface between the bond coat and ceramic top coat and eventually causes cracking and delamination of the top coat. Better understanding and control of the bond coat oxidation dynamics is therefore of primary importance for the development of TBC systems with improved performance. The bond coat is commonly manufactured by thermal spray techniques: the bond coat material, initially in powder form, is heated beyond its melting point, projected onto the surface to be coated and finally re-solidified upon cooling to form a coating. It has been demonstrated that certain microstructural features of the bond coat that are detrimental to its oxidation behaviour originate from thermally induced effects encountered during thermal spraying. Therefore, it is expected that improved bond coat oxidation behaviour could be achieved if the deposition process did not involve significant heating of the material. Recent developments in the surface and coatings industry have given rise to a new coating technology known as Cold Gas Dynamic Spraying (CGDS). As its name implies, this process does not rely on thermal energy for the formation of coatings, but rather on kinetic energy: particles are accelerated above a critical velocity and plastically deform upon impact on the substrate to adhere and form a coating. Due to the absence of significant heating of the sprayed material, this work aims to manufacture bond coats using the CGDS deposition technique and investigate whether improved oxidation behaviour can be achieved. The present thesis provides a description of the experimental approaches considered for the development of CGDS bond coats with improved oxidation behaviour. Given the complexity of TBC systems due to the various interactions between the multiple coating layers, this work strictly concentrates on the bond coat layer without the presence of the superalloy substrate or ceramic top coat, thereby allowing the thorough characterization of the bond coat oxidation behaviour as a function of the initial powder microstructure and different deposition techniques. As such, the objectives of this work are to demonstrate the feasibility of manufacturing bond coats using the CGDS technique, optimize the deposition process for the materials considered, verify whether the CGDS process induces microstructural changes in the deposited material and finally evaluate and compare the oxidation behaviour of CGDS bond coats with those of thermal sprayed bond coats. Results of this work show that bond coatings with conventional and nanocrystalline microstructures were successfully manufactured by the CGDS system developed at the University of Ottawa Cold Spray Laboratory. Optimal spraying parameters were also identified and coatings with low levels of porosity were successfully deposited using this technique. Investigation of the original feedstock powder and resulting coating microstructures revealed that significant microstructural transformations had occurred throughout the CGDS deposition process as a result of extensive plastic deformation of the particles. Isothermal oxidation testing was also carried out on both the conventional and nanocrystalline CGDS coatings. For comparison purposes, thermal spray coatings were also manufactured (using the air plasma spray and high velocity oxy-fuel processes) and subjected to oxidation testing. Results showed that low temperature processing of bond coat materials is beneficial to their oxidation behaviour as it results in coatings with low porosity and limited oxide content, thereby leading to lower oxide growth rates. Furthermore, the CGDS process was observed to produce coatings characterized with fine grain structures (either by means of a grain refinement process of the conventional material or by preserving the fine grain structure of the nanocrystalline material) which was also shown to be beneficial to the oxidation behaviour. Results from this work therefore demonstrate that potentially significant improvements to TBC performance could be achieved by manufacturing bond coats using the CGDS deposition technique.

Download or read book A Fundamental Study of Hot Corrosion and Interdiffusion of Chromium Aluminum and Silicon Coatings on a Nickel 201 Substrate written by Zachery Edward Gill and published by . This book was released on 2014 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern turbine engine systems require increased efficiency and durability. To achieve these goals, high-temperature materials with high-strength, low-cost and non-strategic compositions are needed. In advanced turbine applications, combustor liners, blades and vanes are exposed to corrosive combustion byproducts, such as alkali salts, at temperatures up to ~1700°C with high gas velocities, entrained particulates, and other foreign objects at pressures of up to 3 MPa (30 atm). These extreme conditions can drive a dangerous phenomenon known as "hot corrosion", an accelerated form of oxidation that occurs when metals and metal alloys are heated in the temperature range 700-900°C in the presence of alkali salts. An increased understanding of the fundamental behaviors of common high temperature alloys and their degradation mechanisms is therefore critical for the production of reliable components. In this study a model substrate, Nickel 201, was coated on one side with Cr, Al, or Si thin films (~1 micron) via magnetron sputtering physical vapor deposition (PVD). Uncoated and PVD coated samples were then exposed to laboratory air at 700°C and 900°C and to an environment similar in composition to atmospheres found in post combustion turbine systems, comprised of air/SO 2 gas mixture, at 700°C. The exposures were conducted over time intervals observing coating-substrate interactions and surface oxide development. Identical samples were subjected to the same exposures with addition of a deposit of sodium sulfate (Na 2SO 4), a model alkali salt. Sample mass gains were recorded and resulting oxide compositions assessed as a function of exposure time using microscopy techniques on sample surfaces and cross sections. The development of intermetallic species was determined by X-ray diffraction. At 700°C, coated and uncoated samples displayed different oxidation behaviors. Under laboratory air, no hot-corrosion occurred. While at 700°C in air/SO 2 exposures, evidence for hot corrosion on deposited samples was observed. When sodium sulfate was introduced at 900°C, coated and uncoated samples displayed rapid corrosion consistent with hot corrosion. The oxidation processes and coating/substrate inter-diffusion phenomena are presented and discussed in the context of establishing basic approaches to improve the fundamental understanding of hot corrosion, and the protection mechanisms of high temperature materials.

Download or read book Cold Spray Coatings written by Pasquale Cavaliere and published by Springer. This book was released on 2017-11-08 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book combines the contributions of experts in the field to describe the behavior of various materials, micromechanisms involved during processing, and the optimization of cold-spray technology. It spans production, characterization, and applications including wear resistance, fatigue, life improvement, thermal barriers, crack repair, and biological applications. Cold spray is an innovative coating technology based on the kinetic energy gained by particles sprayed at very high pressures. While the technique was developed in the 1990s, industrial and scientific interest in this technology has grown vastly in the last ten years. Recently, many interesting applications have been associated with cold-sprayed coatings, including wear resistance, fatigue life improvement, thermal barriers, biological applications, and crack repair. However, many fundamental aspects require clarification and description.

Download or read book Heat Treating and Surface Engineering written by ASM Heat Treating Society. Conference and Exposition and published by ASM International. This book was released on 2003-01-01 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Coating Study to Reduce Contact Stress Damage of Ceramics written by J. Schienle and published by . This book was released on 1987 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Surface Engineering written by David S. Rickerby and published by CRC Press. This book was released on 2000 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Surface Engineering, the Proceedings of the Sixth International Conference in the Series 'Engineering the Surfaces', reviews the surfacing technologies appropriate to oxidation, corrosion and thermal protection. This book will be a valuable reference guide for Engineers and Material Scientists.

Download or read book Thermal Barrier Coating on Gamma Titanium Aluminide by Eb Pvd written by Meysam Keshavarz and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal barrier coating (TBC) systems are indispensable for utilization in gas turbine engines to decrease the thermal effect and enhance turbine efficiency by considerably raising applied gas temperatures. TBCs are typically composed of an underlying metallic bond coat known as MCrAlY (M=Ni, Co) acting as an oxidation resistant layer, and yttria-stabilized zirconia (YSZ) as a ceramic top coat that provides thermal insulation toward the metallic substrate. In this study Inter-metallic alloy based on Gamma Titanium Aluminide was chosen as a substrate due to its low density as compared to the conventional Nickel-based super alloy which made it competent to be an important structural material in high-temperature aerospace and automotive applications. TBC's bond coat and ceramic top coat were performed by EB-PVD at different partial pressures of Oxygen during deposition of the top layer in order to get deeper insight into the correlation between adhesion and deposition process parameters.

Download or read book Optimizing the Hot Corrosion Resistance of Novel Gamma Ni gamma prime Ni3A1 Based Alloys and Coatings written by and published by . This book was released on 2006 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: High temperature degradation by hot corrosion (650-1000 C) and/or oxidation (>1000 C) can severely reduce the longevity of advanced gas turbine engine components. The protection of high-temperature components against hot corrosion or oxidation is typically conferred by the application of either a diffusion or overlay metallic coating that is able to form a continuous, adherent, and slow growing oxide scale. There are currently no coatings that provide adequate protection to both hot corrosion and oxidation. This study assesses and advances the performance of novel modified gamma-Ni.+ gamma-prime Ni3Al alloys and coatings. Significant progress was achieved in this study towards the targeted goal of establishing a metallic coating that is highly resistant to both hot corrosion and high temperature oxidation.