Effect of Substrate on In-flight Particle Characteristics in Suspension Plasma Spraying

Effect of Substrate on In-flight Particle Characteristics in Suspension Plasma Spraying PDF Author: Kourosh Pourang
Publisher:
ISBN:
Category :
Languages : en
Pages : 99

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Book Description
Thermal spray technology is a widely used technique in industry in which surfaces of materials are coated by spraying a wide range of metals or ceramics. Considering the growing interest in building nanostructured coatings due to their significant characteristics a new technique called suspension plasma spraying is developed. In this method, a coating is formed by injecting a suspension of nano or sub-micron sized particles into a plasma flame. Obtaining a uniform coating on mechanical parts is one of the industrial challenges in suspension plasma spraying. Through a three dimensional numerical analysis, this study is aimed at providing a better understanding of the effect of substrate position and curvature on in-flight particle temperature, velocity and trajectory. The high temperature and high velocity plasma flow is simulated inside the plasma torch using a uniform volumetric heat source in the energy equation. The suspension of yttria stabilized zirconia (YSZ) particles is used here due to its vast applications in forming thermal barrier coatings. Suspension is molded in this study as a multicomponent droplet while catastrophic breakup regime is considered for simulating the secondary break-up when the suspension interacts with the plasma flow. A two-way coupled Eulerian-Lagrangian approach along with a stochastic discrete model was used to track the particle trajectory. Particle size distribution in the vicinity of the substrate at different standoff distances has been investigated. Then the effect of substrate curvature on in-flight particle characteristics is discussed. The results show that sub-micron particles obtain higher velocity and temperature compared to the larger particles. However, due to the small Stokes number associated with sub-micron particles, they are more sensitive to the change of the gas flow streamlines in the vicinity of the substrate.

Effect of Substrate on In-flight Particle Characteristics in Suspension Plasma Spraying

Effect of Substrate on In-flight Particle Characteristics in Suspension Plasma Spraying PDF Author: Kourosh Pourang
Publisher:
ISBN:
Category :
Languages : en
Pages : 99

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Book Description
Thermal spray technology is a widely used technique in industry in which surfaces of materials are coated by spraying a wide range of metals or ceramics. Considering the growing interest in building nanostructured coatings due to their significant characteristics a new technique called suspension plasma spraying is developed. In this method, a coating is formed by injecting a suspension of nano or sub-micron sized particles into a plasma flame. Obtaining a uniform coating on mechanical parts is one of the industrial challenges in suspension plasma spraying. Through a three dimensional numerical analysis, this study is aimed at providing a better understanding of the effect of substrate position and curvature on in-flight particle temperature, velocity and trajectory. The high temperature and high velocity plasma flow is simulated inside the plasma torch using a uniform volumetric heat source in the energy equation. The suspension of yttria stabilized zirconia (YSZ) particles is used here due to its vast applications in forming thermal barrier coatings. Suspension is molded in this study as a multicomponent droplet while catastrophic breakup regime is considered for simulating the secondary break-up when the suspension interacts with the plasma flow. A two-way coupled Eulerian-Lagrangian approach along with a stochastic discrete model was used to track the particle trajectory. Particle size distribution in the vicinity of the substrate at different standoff distances has been investigated. Then the effect of substrate curvature on in-flight particle characteristics is discussed. The results show that sub-micron particles obtain higher velocity and temperature compared to the larger particles. However, due to the small Stokes number associated with sub-micron particles, they are more sensitive to the change of the gas flow streamlines in the vicinity of the substrate.

Particle Image Velocimetry of Suspension Plasma Spray in the Vicinity of a Substrate

Particle Image Velocimetry of Suspension Plasma Spray in the Vicinity of a Substrate PDF Author: Sadaf Mohammadi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Thermal spray technology is a widely used technique in the industry in which surfaces of components are coated by spraying a wide range of metals or ceramics. Considering the growing interest in building nanostructured coatings due to their unique characteristics, a new technique called suspension plasma spraying is developed. Suspension plasma spraying (SPS) is one of the promising methods that can be used to achieve coatings with fine microstructure and superior properties. Several significant parameters make this SPS process complex to understand and control. In particular, the velocity and diameter of in-flight particles near the substrate, which depend on the plasma and injection conditions, have a strong influence on the coating columnar structure. In this work, the velocity of in-flight particles in the vicinity of the substrate and free jet was investigated by the particle image velocimetry (PIV) method. This study is aimed at providing a better understanding of the behavior of in-flight particles in the SPS process. A suspension of titania particles is used here taking advantage to the abundance and chemical stability of titania and its use in different SPS applications. Observations and results of this work showed that the trajectory and velocity of micron-size particles, due to their small Stokes number, are strongly influenced by the presence of the substrate. The PIV results make it possible to visualize the suspension injection into the plasma with titania aqueous suspension. Particle velocity reported by PIV method corresponded likely to un-molten particles in SPS process. The PIV measurements were finally compared with velocity measurements carried out with a thermal-emission particle sensor in the same spray condition as the PIV run.

Handbook of Thermal Science and Engineering

Handbook of Thermal Science and Engineering PDF Author:
Publisher: Springer
ISBN: 9783319266947
Category : Science
Languages : en
Pages : 0

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Book Description
This Handbook provides researchers, faculty, design engineers in industrial R&D, and practicing engineers in the field concise treatments of advanced and more-recently established topics in thermal science and engineering, with an important emphasis on micro- and nanosystems, not covered in earlier references on applied thermal science, heat transfer or relevant aspects of mechanical/chemical engineering. Major sections address new developments in heat transfer, transport phenomena, single- and multiphase flows with energy transfer, thermal-bioengineering, thermal radiation, combined mode heat transfer, coupled heat and mass transfer, and energy systems. Energy transport at the macro-scale and micro/nano-scales is also included. The internationally recognized team of authors adopt a consistent and systematic approach and writing style, including ample cross reference among topics, offering readers a user-friendly knowledgebase greater than the sum of its parts, perfect for frequent consultation. The Handbook of Thermal Science and Engineering is ideal for academic and professional readers in the traditional and emerging areas of mechanical engineering, chemical engineering, aerospace engineering, bioengineering, electronics fabrication, energy, and manufacturing concerned with the influence thermal phenomena.

Micro Process and Quality Control of Plasma Spraying

Micro Process and Quality Control of Plasma Spraying PDF Author: Guozheng Ma
Publisher: Springer Nature
ISBN: 9811927421
Category : Technology & Engineering
Languages : en
Pages : 679

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Book Description
This book focuses on the basic physical process and chemical reaction of plasma spraying particle melting, flight and deposition. It introduces the basic scientific contents such as the basic characteristics and spraying principle of plasma arc, the interaction between spraying particles in flight section and plasma jet, the spreading and solidification behavior of single droplet and the performance test of flat particles, macro performance evaluation and quality optimization of coating. The typical applications of plasma spraying coating and the new developing direction of plasma spraying technology are summarized. This book will be helpful for the graduate students, researchers, as well as engineers in the field of plasma spray.

Inorganic and Organic Thin Films

Inorganic and Organic Thin Films PDF Author: Yujun Song
Publisher: John Wiley & Sons
ISBN: 3527345019
Category : Technology & Engineering
Languages : en
Pages : 768

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Book Description
Learn more about foundational and advanced topics in polymer thin films and coatings besides species with this powerful two-volume resource The two-volume Inorganic and Organic Thin Films: Fundamentals, Fabrication, and Applications delivers a foundational resource for current researchers and commercial users involved in the design and fabrication of thin films. The book offers newcomers to the field a thorough description of new design theory, fabrication methods, and applications of advanced thin films. Readers will discover the physics and chemistry underlying the manufacture of new thin films and coatings in this leading new resource that promises to become a handbook for future applications of the technology. This one-stop reference brings together all important aspects of inorganic and polymeric thin films and coatings, including construction, assembly, deposition, functionality, patterning, and characterization. Explorations of their applications in industries as diverse as information technology, new energy, biomedical engineering, aerospace, and oceanographic engineering round out this fulsome exploration of one of the most exciting and rapidly developing areas of scientific and industrial research today. Readers will also learn from: A comprehensive introduction to the progress of thin films and coatings as well as fundamentals in functional thin films and coatings An exploration of multi-layered magnetic thin films for electron transport control and signal sensing, including giant magnetoresistance, colossal magnetoresistance, tunneling magnetoresistance, and the quantum anomalous Holzer effect An in time summary of high-quality magneto-optics, nanophotonics, spin waves and spintronics using bismuth-substituted iron garnet thin films as examples A thorough discussion of template-assisted fabrication of nanostructure thin films for ultrasensitive detection of chemicals and biomolecules A treatment of biomass derived functional films and coatings Perfect for materials scientists and inorganic chemists, Inorganic and Organic Thin Films will also earn a place in the libraries of solid state physicists and physical chemists working in private industry, as well as polymer and surface chemists who seek to improve their understanding of thin films and coatings.

Ceramic Coatings for High-Temperature Environments

Ceramic Coatings for High-Temperature Environments PDF Author: Amirhossein Pakseresht
Publisher: Springer Nature
ISBN: 3031408098
Category : Technology & Engineering
Languages : en
Pages : 493

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Book Description
This book addresses the recent trends in thermal and environmental barrier coatings and their applications in extreme environments. It introduces the state of the art in coating materials and processes for high and ultrahigh-temperature environments and identifies areas for improvement in materials selection, performance upgrades, design considerations, and manufacturing methods. This book also covers fundamental studies involving modelling, creating coating architectures, coating preparation methods, and coating capability throughout a wide temperature range. The book examines a variety of high-temperature coatings prepared through various synthesis processes such as thermal spraying, electron beam evaporation, and sol–gel methods. This book also covers ultrahigh-temperature ceramic (UHTC) materials and provides a brief overview of the synthesis method, densification processes, and coating methods along with the properties and applications of emerging high entropy UHTCs. 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 materials scientists and engineers working in the area of high and ultrahigh-temperature ceramic materials.

Plasma-Spray Coating

Plasma-Spray Coating PDF Author: Robert B. Heimann
Publisher: John Wiley & Sons
ISBN: 3527614842
Category : Technology & Engineering
Languages : en
Pages : 354

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Book Description
Over the past two decades, thermal spraying of metallic, ceramic and composite coatings has emerged as a powerful tool for surface engineering, with many new applications and markets continually being developed. This book will help materials scientists and engineers to choose the most appropriate combination of materials, equipment, and operation parameters for the design of high-performance coatings with new functional properties and improved service life. Includes: * a thorough treatment of the fundamental physical processes governing plasma spray technology; * a critical assessment of advantages and disadvantages of the method compared with other suface coating techniques; * a discussion of basic equipment requirements and limitations; * case studies and typical applications to solve industrial problems. Plasma-Spray Coating offers a stimulating combination of basic concepts and practical applications. Materials scientists and engineers, as well as graduate students will find this book of enormous value.

Numerical Modeling of Suspension and Particle Transport in Thermal Spray Processes

Numerical Modeling of Suspension and Particle Transport in Thermal Spray Processes PDF Author: Mehdi Jadidi
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

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Book Description
Fine microstructured coatings have attracted many attentions in recent years due to various unique properties such as remarkable wear resistance, enhanced catalytic behavior, and superior thermal insulation. Suspension thermal sprays have been shown to be viable techniques in generating this kind of coatings. In these techniques, suspension which is a combination of a base liquid and fine solid particles is injected into a high-temperature high-velocity jets. After suspension breakup, the evaporation/combustion of base liquid becomes dominant. Then, the remained particles are accelerated and heated up by the gas flow and are deposited on a substrate which results in the generation of dense and well-adhered coatings. Suspension thermal spraying is very complex and many fields such as turbulent flow, multiphase flow, compressible flow, combustion, atomization, suspension properties, and plasma physics are involved in the mentioned technique. In addition, many parameters and mechanisms in this technique are still unknowns. Therefore, both numerical and experimental studies should be performed to obtain a comprehensive understanding of various phenomena in suspension thermal spraying and to improve the coating quality. The main goal of this study is the numerical modeling of suspension thermal sprays. An Eulerian-Lagrangian approach with two-way coupling assumption is presented and suspension droplet evolution in the atmospheric plasma spraying and high velocity oxygen fuel spraying techniques is investigated. In this model, suspension is considered as a multi-component mixture and a predefined droplet distribution is injected into the jet. In this approach, the breakup process is simulated using Taylor Analogy Breakup (TAB), and Kelvin-Helmholtz Rayleigh-Taylor (KHRT) breakup models. After breakup process is complete, the liquid component of suspension droplet evaporates/burns, and the particles/agglomerates are tracked in the domain. In general, the effects of suspension injection velocity, suspension properties, suspension injector location, standoff distance, substrate shape, and gas properties on the coating characteristics can be investigated by this approach. For example, in the case of radial injection of suspension into a plasma plume, it is illustrated that if particles move close to the jet centerline, particle velocity and temperature as well as probability of particle impact on the substrate will increase. The mentioned Eulerian-Lagrangian approach revealed that the breakup phenomenon mainly controls the droplets/particles trajectories, temperatures and velocities. However, the typical TAB and KHRT models ignore liquid/suspension column deformation, and need experimental calibration. To study the breakup process in more details, the effect of nonuniform gaseous crossflow and liquid column perturbations on the primary breakup of liquid jets are investigated. A coupled level set and volume-of-fluid method together with the large eddy simulation turbulence model are used to study the behavior of nonturbulent liquid jets in nonuniform crossflows. It is shown that liquid penetration height is significantly affected by the crossflow nonuniformity. In addition, to investigate the effects of liquid column perturbations on the breakup process, experimental studies are performed using shadowgraphy technique. General correlations for the penetration height, the column breakup point, and the onset of surface breakup are presented. It is found that the liquid column perturbations result in formation of large ligaments very close to the liquid and gas flows interaction point. These ligaments control the droplet size distribution and have significant effects on particle in-flight behavior, and coatings quality. The results of these studies can be used to estimate the spray trajectory in suspension plasma spray process, and to improve the accuracy of TAB and KHRT breakup models.

Thermal Spray Fundamentals

Thermal Spray Fundamentals PDF Author: Pierre L. Fauchais
Publisher: Springer Science & Business Media
ISBN: 0387689915
Category : Technology & Engineering
Languages : en
Pages : 1587

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Book Description
This book provides readers with the fundamentals necessary for understanding thermal spray technology. Coverage includes in-depth discussions of various thermal spray processes, feedstock materials, particle-jet interactions, and associated yet very critical topics: diagnostics, current and emerging applications, surface science, and pre and post-treatment. This book will serve as an invaluable resource as a textbook for graduate courses in the field and as an exhaustive reference for professionals involved in thermal spray technology.

Environmental Barrier Coatings

Environmental Barrier Coatings PDF Author: Kang N. Lee
Publisher: MDPI
ISBN: 3039365177
Category : Science
Languages : en
Pages : 168

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Book Description
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.