bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationships Between Coating Microstructure and Thermal Conductivity in Thermal Barrier Coatings – a Modelling Approach
Authors: Tano I. , Gupta M. , Curry N. , Nylén P. , Wigren J. 
Published: September 2022

Abstract
Fundamental understanding of relationships between coating microstructure and thermal conductivity is important to be able to understand the influence of coating defects, such as delaminations and pores, on heat insulation in thermal barrier coatings. Object-Oriented Finite element analysis (OOF) has recently been shown as an effective tool for evaluating thermo-mechanical material behaviour, because of this method’s capability to incorporate the inherent material microstructure as an input to the model. In this work, this method was combined with multi-variate statistical modelling. The statistical model was used for screening and tentative relationship building and the finite element model was thereafter used for verification of the statistical modelling results. Characterisation of the coatings included microstructure, porosity and crack content and thermal conductivity measurements. A range of coating architectures was investigated including High purity Yttria stabilised Zirconia, Dysprosia stabilised Zirconia and Dysprosia stabilised Zirconia with porosity former. Evaluation of the thermal conductivity was conducted using the Laser Flash Technique. The microstructures were examined both on as-sprayed samples as well as on heat treated samples. The feasibility of the combined two modelling approaches, including their capability to establish relationships between coating microstructure and thermal conductivity, is discussed.
Influence of Helium and Nitrogen Gases on the Properties of Cold Gas Dynamic Sprayed Pure Titanium Coatings
Authors: Wong W. , Irissou E. , Legoux J.-G. , Yue S. 
Published: September 2022

Abstract
This study investigated the effect of the type of gas used, nitrogen and helium, during cold spraying of titanium coatings. In all conditions, the propelling gases’ temperature and pressure were attuned to attain three similar particle velocities for each gas. Coatings were characterized by SEM and XPS. Deposition efficiency, coating microhardness, and porosity were evaluated for all conditions. Results show that for the same particle impact velocity, the deposition efficiency and coating density were mostly the function of the surface temperature, which in turn was influenced by spray parameters. It is shown that loosely-bonded particles at the surface can be detached by the passage of high pressure supersonic gas stream. In addition, a thick and fully dense cold sprayed titanium coating was achieved with optimized spray parameters with He and the corresponding average particle velocity was measured at 1173 m/s.
Correlation of Wear Resistant Functions of HVOF and Warm Sprayed WC-Co Coatings with In-Flight Particle Characteristics
Authors: Sato K. , Kitamura J. , Raman G. , Watanabe M. , Komatsu M. , Kuroda S. 
Published: September 2022

Abstract
WC-Co thermal sprayed coatings are mainly used for wear protecting functions in various industries, for which high velocity oxy fuel (HVOF) spray is considered to be the best suited process. However, WC-Co HVOF coatings still have some defects as compared with sintered bulk, such as decarburization of WC and porous structure. Recently, experiments of WC-Co coatings using warm spray (WS) and cold spray processes have demonstrated some improvements in reduction of these defects. In particular, WS process seems to be a more promising process for WC-Co coatings from the previous work. In this study, wear resistant functions of WC-12%Co coatings prepared by HVOF and WS were investigated by abrasion and erosion tests. In addition, in-flight particles were captured and their characteristics such as the amount of decarburization, crystal phase, particle strength and particle size distribution were investigated to clarify the difference between HVOF and WS processes. The result shows that the wear resistances of the WC-Co WS coatings are comparable or superior to those of the HVOF coatings, which can be attributed to the difference in the amount of W2C and coatings porosity revealed by the in-flight particles and the coating microstructure. The result of the in-flight particle analysis also indicates that wear resistance of WS coatings can be further improved by optimizing the powder shape and chemical composition.
Plasma Sprayed LSCF Oxygen Electrode for SOFC
Authors: Ansar A. , Soysal D. , Ilhan Z. , Wagner N. 
Published: September 2022

Abstract
La1-xSrxCo0.2Fe0.8O3-δ deposits, of different stoichiometry, were fabricated for SOFC oxygen electrode using atmospheric plasma spraying (APS) with TriplexPro gun. The spraying conditions were developed by correlating, plasma jet characteristics (enthalpy and velocity), in-flight particle properties (temperature and velocity) and deposit quality (phase composition, porosity, coefficient of thermal expansion, electrochemical testing). The optimal cathode deposits exhibited a porosity of about 20 vol.%. The CTE in air flow at 800 °C was, however, 15.6 x 10-6 K-1 and it was independent of the processing conditions. Electrochemical tests for cathodes were conducted on SOFCs that were produced following metal supported design and had YSZ as electrolyte and NiO+YSZ as anode. At 800 °C, power densities of above 640 mW/cm2 at 0.7 V were recorded with H2/air for cell having La0.60Sr0.40Co0.2Fe0.8O3-δ as cathode. Cells consisting of La0.58Sr0.4Co0.2Fe0.8O3-δ and La0.78Sr0.2Co0.2Fe0.8O3-δ had 479 and 496 mW/cm2 under similar conditions. Using equivalent circuit diagrams the contribution of different polarizations on the cell performance were separated and cathodes were compared. La0.60Sr0.40Co0.2Fe0.8O3-δ was found to have the best electrochemical performance followed by La0.58Sr0.40Co0.2Fe0.8O3-δ and La0.78Sr0.20Co0.2Fe0.8O3-δ.
The Next Step in Intelligent Gun Technology – EvoLink for Plasma Spraying
Authors: Koller M. , Kilchenmann A. 
Published: September 2022

Abstract
As the requirements placed on thermal coatings become increasingly stringent, being able to acquire more accurate data more quickly is becoming increasingly important. To achieve this, process variables must be measured close to or even inside the gun. This paper introduces a new product which measures process variables directly inside a thermal spray gun. It explains the advantages of measuring the process variables inside the gun, but also why it is important to have gun-relevant data stored on the gun itself.
Measurement of Particle Parameters in Detonation Spraying
Authors: Smurov I. , Pervushin D. , Chivel Yu. , Laget B. , Ulianitsky V. , Zlobin S. 
Published: September 2022

Abstract
Measurement of the particle temperature and velocity in detonation spraying is significantly complicated by the pulsed character of the process. In the present study, these parameters are measured for powders with strongly different nature and properties such as WC/Co, Inox and Ti. Experiments are performed using an original computer-controlled detonation spraying (CCDS) installation developed by the authors. The system is distinguished by the mode of powder feeding into the gun barrel which is pulsed in time and localized in space. Evolution of the particle-in-flight velocity and size is examined by an original CCD-camera-based diagnostic tool developed by the authors. A significant spatial separation of the particles along the detonation plume is observed during their acceleration: 15 μm fine particles overtake 45 μm coarse particles by more than 10 plume diameters. For this reason, distributed scanning over the plume length is applied in order to obtain adequate results. A previously developed mathematical model of the process is experimentally validated. Calculations are found to be in a qualitative agreement with the experimental results. As far as particle-in-flight velocity is concerned, the agreement is even quantitative.
Measurement of Particle Emissions Generated by Arc Spray and Flame Spray Processes
Authors: Billières D. , Bémer D. , Subra I. , Lecler M. , Régnier R. , Morele Y. , Gutha J. 
Published: September 2022

Abstract
Thermal spray of Zn, Zn/Al, or Al is extensively used to make anticorrosion coatings on steel structures. Twin arc spray and wire flame spray are the two most practised processes to achieve such coatings. This paper presents measurements of particle emissions generated by these two processes. Sampling and analysis of aerosols generated by both processes have been carried out inside the exhaust ductwork using various instruments: an ELPI impactor, a CNC (Condensation Nucleus Counter), a TEOM microbalance and sampling filters allowing sampling for SEM observations. Electric arc spraying produced much more fumes of ultra fine particles than flame spraying. Aluminum spraying also produces large fume quantities compared to the Zn spraying under the same conditions. The aerosol comprised submicron particles and 95% of the numerical particle size distribution was less than 100 nm. The nanometric nature of the fume particles was confirmed by observations on the SEM. The strong dilution caused by compressed air has the effect of strongly limiting particle coagulation and, in turn, the size of the agglomerated particles. Electric arc spray has taken market share versus wire flame spray for Zn, ZnAl, or Al spraying, but this study shows that it generates much more particle emissions.
Study of the Influence of Pre-Heated Al6061 Substrate Temperature on Al Coatings Deposited by Cold Spray
Authors: Rech S. , Trentin A. , Vezzù S. , Legoux J.-G. , Irissou E. , Guagliano M. 
Published: September 2022

Abstract
In this work, the influence of the substrate temperature on the deposition efficiency and on the coating properties and residual stress was investigated. Pure Al coatings were deposited on Al 6061 alloy substrates using CGT Kinetics 3000 deposition system. The substrate temperature was ranged between 20°C (room temperature) and 375 °C and was kept nearly constant during the deposition while all the other deposition parameters were unchanged. The deposited coatings were quenched in water (within one minute from the deposition) and then characterized. The residual stress was determined by Almen gage method (Ref 1, 2, 3), Modified Layer Removal Method (Ref 4, 5, 6), and XRD (Ref 7) in order to identify both the mean coating stress and the stress profile through the coating thickness from the surface to the coating- substrate interface. The residual stress results obtained by these three methods were compared and discussed. The coating morphology and porosity were investigated using optical and scanning electron microscopy.
Comparative Study of the Electrical Properties and Microstructures of Thermally Sprayed Alumina and Spinel Coatings
Authors: Toma F.-L. , Scheitz S. , Berger L.-M. , Sauchuk V. , Kusnezoff M. 
Published: September 2022

Abstract
In the present work, APS and HVOF processes have been used to prepare alumina (Al2O3) and magnesium aluminate spinel (MgAl2O4) coatings designed for electrical insulating applications. The microstructures and the phase compositions of the sprayed coatings were evaluated by microscopic and XRD analysis. The electrical characteristics electrical resistance, electrical resistivity and dielectric breakdown strength were investigated using different methods: direct current (DC) measurements, electrochemical impedance spectroscopy (EIS) and dielectric breakdown testing. The electrical resistance was measured at room temperature at different humidity levels. Differences in the insulating properties due to the different natures of the coating materials, microstructures and the measurement methods used for electrical characterisation are discussed.
Microstructures of Metallic NiCrBSi Coatings Manufactured via Hybrid Plasma Spray Process
Authors: Serres N. , Hlawka F. , Costil S. , Langlade C. , Machi F. 
Published: September 2022

Abstract
This paper deals with coating alternatives to hard chromium plating. Indeed, thermal spraying is already used in industry, but results are not always satisfactory for reasons of porosity and microstructures. In this study, atmospheric plasma spraying (APS) and in situ laser irradiation by diode laser processes were combined to modify the structural characteristics of thick NiCrBSi alloy layers. The microstructure evolution was studied and results show that in situ laser remelting induces the growth of a dendritic structure which strongly decreases the porosity of as-sprayed coatings and increases the adhesion on the substrate. Moreover, no phase transition after laser treatment is observed. At least, a mechanical investigation demonstrates that the combination between the plasma spraying and in situ melting with a diode laser can result in the improvement of mechanical properties. The hybrid process appears to be a possible alternative to hard chromium plating, in order to protect mechanical parts, because of the good mechanical behaviour of NiCrBSi layer. Moreover, the increase of the laser incident power causes an increase of the mean contact pressure, along with coatings hardness.
Tungsten-Based Coatings to Increase the Lifetime of Permanent-Mold Casting Molds
Authors: Wilden J. , Drescher V.E. 
Published: September 2022

Abstract
Molten metals are extremely corrosive against steel-made molds. In addition to alternating thermal loads and erosion by hard particles the lifetime of molds in the permanent-mold casting industry is rather short. Tungsten-based pseudoalloys are able to increase the lifetime of these molds significantly, but, by now, their use is limited to sintered inlays at the mostly stressed parts of the mold. Coating the whole mold with these materials offers an increase of the lifetime and at the same time a reduction of the amount of deployed feedstock. Within this research project it was possible to increase the lifetime of a kernel in used in casting brass by a factor of 20 by cladding it with tungsten-based pseudoalloys. The metallurgical behaviour of the tungsten-based pseudoalloys is quite complex. By modifying the coating process different shapes and amounts of tungsten precipitations in the nickel-iron-binder can be realized. The different microstructure within the coating does strongly affect the mechanical and anti-corrosion properties of the coating.
Extension of Erosion Life of Turbine Housing for Ship by Thermal Spray
Authors: Sonoya K. , Nakamura M. , Ishida K. 
Published: September 2022

Abstract
The blast erosion-resistance properties of HVOF thermal spray Cr3C2 type coating system and aluminized material were examined to improve erosion-resistance of turbine housings of compressors used in turbochargers for marine diesel engines. As a result, the erosion life of aluminized material is as same as that of the substrate, on the other hand the erosion life of thermal sprayed coating is ten times of that of the substrate. Therefore, erosion life of turbine housing can be extended by the surface treatment procedure. This technology is applicable to actual products.
Wear Properties of Ni-Based Composite Coatings Sprayed by HVAF
Authors: Wu C. , Zhou K. , Liu M. , Deng C.M. , Deng C.G. 
Published: September 2022

Abstract
In order to explore wear properties of Ni-based coating on the copper substrate, the coatings with different composition were designed. Ni-based coating, Ni-based/Al2O3 and Ni-based/Al2O3/WC coatings were sprayed by HVAF on the copper substrates. Wear properties of different composite coating were measured at different loads at room temperature. The experimental results indicate that all the coatings have high wear resistance. Adding Al2O3 in sprayed powders has little effect on the microstructures and wear properties of coating. The wear resistant is improved by the addition WC-12Co obviously. The best wear resistant is obtained when optimum WC-12Co content is added.
Coating of Aluminum Components with Iron-Based Nanocrystalline Solidifying Materials to Improve Wear Resistance
Authors: Wilden J. , Drescher V.E. , Lehmann O. 
Published: September 2022

Abstract
Conventional processes of gas shielded metal arc welding (GMAW) do not offer directly the possibility for cladding heat sensitive materials such as aluminum with iron-based materials due to intermetallic Al/Fe phases form. This paper deals with the first evaluated cladding results of aluminum components with iron-based nanocrystalline solidifying materials by controlled shielded metal arc welding processes to improve wear resistance. In the present work, the design of experiments and data evaluations are systematically applied to get the first results about the dependence between controlled arc welding process parameters and the iron-based coatings of aluminum substrate. In particular, the effect of the chosen parameters such as wire feed speed, welding speed, frequency and further factors on the heat input, welding penetration, micro hardness, rate of welding penetration and width of intermetallic phases in the interface zone are investigated. Optical and scanning electron spectroscopy provide input for further statistical evaluation. The experiments were carried out using various controlled arc technologies which offer different control over the heat input to the substrates. Different power supplies were used.
Velocity Diagnostics for Gas Velocity Distributions in Cold Gas and Plasma Spraying Using Non-Resonant Laser Scattering
Authors: Lange S. , Sieber M. , Forster G. , Marqués J.L. , Schein J. 
Published: September 2022

Abstract
In cold spray and thermal spray applications, one of the primary factors affecting coating deposition is the location where particles are injected into the gas jet. Therefore, a detailed knowledge of the gas flow distribution is required. Non-resonant laser scattering allows to spatially resolve the distribution of drift velocity and mass density within the flow, particularly at locations close to the injector. Based on laser scattering, this paper presents a new diagnostic that locally measures drift velocity, as well as a relative mass density distribution of a gas stream. Its application is mainly focused on cold gas flows, where velocity measurements in a supersonic nozzle, obtained by means of laser scattering, correlate well with theoretical calculations and particle image velocimetry (PIV) experimental results.
Thermal Spray Forming of High-Efficiency, Metal-Foam Heat Exchanger Tubes
Authors: Tsolas N. , Chandra S. , Salimjazi H. , Pershin V.I. , Mostaghimi J. 
Published: September 2022

Abstract
Thermal spray coating processes have been employed in the current study to deposit well-adhered, dense skins on the surfaces of open-cell nickel foams. Using foam with 10 and 40 PPI (pores per inch) pore sizes, square channels were made with a height of 20mm and having a length of 250mm. In a unique process that prevents the deposited skin from penetrating the foam substrate via a paste comprised of a thermoset resin and powder particles, a dense stainless steel skin with an average thickness of 400 μm is applied to the exterior of the foam sample. The result is a channel that consists of a Ni foam core and a stainless steel skin wall that can be used as a compact heat-exchanger by directing the coolant flow through the foam. To study the feasibility of the metallic foam heat-exchangers, hydraulic and heat-transfer characteristics were investigated experimentally. The local wall and fluid temperature distribution and the pressure drop along the length of the heat exchanger were measured for heat-flux of 1540.35 – 9627.38 W/m2. Experiments were conducted using air as the coolant and varying flow velocity from 10 – 80 L/min. For non-Darcy flow with inertia effects in the porous media, the Dupuit and Forchheimer modification is employed with the experimental results to determine foam characteristics such as permeability (K), Ergun coefficient (CE) and the friction factor (f). To measure the heat-transfer performance of the metal foam filled channels, a length average Nusselt number is derived based on the local wall and fluid temperatures. Heat transfer was shown to have nearly doubled compared to that of a channel without a foam core.
Challenges for Plasma Spray Deposition of Decomposition-Prone Perovskite Coatings
Authors: Jarligo M.O. , Mauer G. , Mack D. , Vassen R. , Stöver D. 
Published: September 2022

Abstract
Processing of powder feedstock materials often influences the deposition behavior and ultimately, the properties of the atmospheric plasma spray (APS) deposited coatings. The necessity of materials design and the control of deposition parameters are therefore, of high importance. Feedstock from promising ceramic thermal barrier coating materials with Ba(Mg1/3Ta2/3)O3 and La(Al1/4Mg1/2T1/4)O3 perovskite structures (λ~ 2 W/m-K and α~11x10-6 /K at 1473 K) were prepared through solid state and conventional spray drying techniques. The powders were then deposited on metallic substrates by APS process. Monitoring of in-flight particle characteristics and splat formation as well as characterization of deposited coatings, were conducted. It was found that these types of perovskite materials tend to lose constituents during deposition by atmospheric plasma spraying. This paper reports on the challenges of powder feedstock design and the control of critical deposition parameters to prevent or minimize the non-stoichiometric deposition of decomposition-prone perovskite coatings by APS process.
The Structure and Properties of Plasma Sprayed Fe Doped Manganese Cobalt Oxide Spinel Coatings for SOFC Metallic Interconnectors
Authors: Puranen J. , Lagerbom L. , Hyvärinen L. , Kylmälahti M. , Vuoristo P. 
Published: September 2022

Abstract
Manganese cobalt oxide spinel doped with Fe2O3 was studied as protective coatings on alloyed metallic interconnect plates for solid oxide fuel cell applications. Chromium alloying causes problems at high operation temperatures in oxidising conditions, on the cathode side of the fuel cell. The formed chromium oxide layer tends to form a thin layer of chromium trioxide or chromium hydroxide which evaporates at certain oxygen partial pressures more easily than chromium oxide and thus poisons the cathodes active area causing the degradation of the solid oxide fuel cell. Thermal spraying is regarded as a promising way to produce dense and protective layers on top of ferritic steels to lower the degradation processes and extend the lifetime of the SOFC device. In the present work, the ceramic Co-Mn-oxide spinel coatings were produced by using the atmospheric plasma spray process. The structures and compositions of the coatings were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) was used to study the phase structure in as-sprayed and heat treated coatings and mechanical properties were examined by using micro hardness tester. Coatings with low thickness and micro structurally dense structures were produced by using optimal deposition conditions.