bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Surface Morphology of MCrAlY Bond Coats on the Isothermal Oxidation Behavior
Authors: Li Y. , Li C.-J. , Zhang Q. , Xing L.-K. , Yang G.-J. 
Published: September 2022

Abstract
Surface morphology of MCrAlY bond coats is one of the factors that affect the oxidation behavior and the thermal stability of thermal barrier coatings. In the present study, the isothermal oxidation behavior of cold sprayed MCrAlY bond coat was investigated at three surface conditions: as-sprayed, polished and shot-peened conditions. The MCrAlY bond coat with sputters adhered weakly on the surface prepared by low-pressure plasma spraying was also employed. The above four types of surface conditions were employed to investigate the effect of the surface morphologies of MCrAlY (M=NiCo, Ni) bond coats on their oxidation behavior. MCrAlYs with the compositions of Ni20Cr10AlY and Ni23Co20Cr8.5Al5.0Ta0.6Y were employed for bond coat deposition. Cold-sprayed Ni20Cr10AlY exhibited a higher oxidation rate than that of the cold-sprayed Ni23Co20Cr8.5Al5.0Ta0.6Y bond coats. After 10 hrs oxidation, the TGO on the as-cold-sprayed bond coat surface was merely constituted by Al2O3, while the TGO on the bond coat surface attached with sputters was composed of Al2O3 and spinel. After 500 hrs oxidation, Cr2O3 and porous spinel appeared in the TGO on the two surfaces of as-cold-sprayed bond coat. The growth of Ni/Cr-oxides was attributed to the Al depletion. The content of spinel on cold-sprayed NiCrAlY decreased after shot-peening.
Loading Effect in Plasma Spraying: from In-Flight Particle State Distributions to Diagnostic Reliability
Authors: Shinoda K. , Tan Y. , Sampath S. 
Published: September 2022

Abstract
The effects of powder loading on temperature distributions of yttria-stabilized zirconia particles during flight, which can be used as a melting status indicator, were investigated in atmospheric dc plasma spraying. Commercially available diagnostic systems were utilized to measure the state of in-flight particle parameters. As the powder feed rate was increased, the intensity of a peak related to the latent heat increased, suggesting the increase of semi molten particles. Interesting findings are that the deposition efficiency of the coating actually increased in some conditions at higher powder feed rates. This implies that higher molten degrees of particles do not always give higher deposition efficiencies. The loading effects also affected the result of diagnostics, which requires special care when the diagnostic condition is different from the actual spray conditions.
The Improvements of Thermal Spray Toolkit, Extended Software for Robotic Off-Line Programming
Authors: Fang D. , Deng S. , Liao H. , Coddet C. 
Published: September 2022

Abstract
Thermal Spray Toolkit (TST) is an extended program (Add-in) of RobotStudio which is off-line programming software of ABB Company. The Thermal Spay Toolkit can generate the robot trajectories rapidly, accurately and automatically for most workpieces with a simple and regular form. In recent years, the growing demand for spraying workpiece of various shapes provides a strong motivation to develop new functions to Thermal Spray Toolkit. This paper describes the development of thermal spray toolkit and presents new functions: robotic trajectory auto-generation for complicated surfaces and the optimization of trajectory. Furthermore, many simulations are implemented to optimize trajectory in RobotStudio. Compared to the former thermal spraying without applying this toolkit, the coating quality is improved greatly. These results demonstrate that the new functions are reliable and efficient.
Improved Mechanical Properties of Coatings and Bulk Components as a Function of Grain Size
Authors: Melnyk C. , Schroeder S. , Grant D. , Gansert R. , Watson M. 
Published: September 2022

Abstract
Thermal sprayed coatings produced from ultrafine- and nano- and near-nano grained powders of tungsten carbide- 10 wt.% cobalt-4 wt.% chromium (WC-10Co-4Cr) are reported to provide improved properties as compared to conventional powders. These materials show great potential for applications in the aerospace, oil & gas, power, and many other industries. A study is proposed to investigate the influence of WC grain size on HVOF coating properties. Thermal spray coatings will be produced from powders consisting of grains of WC from micron- to near-nano in size in a Co-Cr matrix. The Hall-Petch relationship cites the strengthening of materials by reducing the average crystallite (grain) size. An examination of consolidated forms will be performed using the same powders used in thermal spray in the spark plasma sintering (SPS) consolidation. The mechanical properties of thermal spray coatings have been reported to relate to those of bulk materials. Improvements observed in the HVOF spray coatings will be compared to those of bulk samples.
Effect of Stand-Off Distance on EMAA Splats Deposited onto Glass and Mild Steel Substrates
Authors: Xie W. , Saber-Samandari S. , Morks M. F. , Alamara K. , Wang J. , Berndt C. 
Published: September 2022

Abstract
Thermal spray coatings are comprised of millions of heated particles that are driven at high velocity to impact against a substrate; thereby building up to form a consolidated coating. Thus, investigating single solidified droplets contributes to fundamental understanding of coating evolution and their properties. In this study, Scanning Electron Microscopy (SEM) studied the splat morphology of flame sprayed ethylene methacrylic acid (EMAA) with respect to the stand-off distance when deposited onto glass and mild steel substrates. A splat shape transition from a “splash” to a “disc shape” was observed. The morphology of EMAA droplets can be described as a ‘splash splat’ when sprayed onto mild steel at room temperature, whereas a 35 cm stand-off distance produced a disk-shaped splat when the polymer was deposited onto a glass substrate.
Effect of The Ceramic Component on Cold Sprayed Metal Ceramic Coatings
Authors: Sova A. , Kosarev V. , Papyrin A. , Smurov I. 
Published: September 2022

Abstract
Spraying metal-ceramic coatings is a complicated task because, in addition to the spray parameters of the metal particles, it is necessary to take into account those of ceramics. This paper presents some results concerning the effect of the nature, particle size, and velocity of ceramics on the metal-ceramic coating properties. Copper and aluminium powders are used as metal components. Two fractions (fine and coarse) of aluminium oxide and silicon carbide are sprayed in the tests. Ceramic particle velocity is varied by the particle injection into different zones of the gas flow: in the subsonic (pre-chamber) and supersonic parts of the nozzle, and in the free jet after the nozzle exit. Simulation results and measurements of the particle velocity by the track method are compared. Influence of the ceramic particle parameters on the coating formation process and its properties is discussed.
Near-Net-Shape HVOF Coating and Finishing Techniques for Highly Stressed Components in Aircraft Industry
Authors: Matthäus G. , Wolf J. , Ackermann D. 
Published: September 2022

Abstract
Applications such as landing gears and turbine blades place new demands on near-net coating technologies. Such demands include the replacement of traditional grinding, finishing and grit basting techniques with better, more efficient methods. A method is described for near-net-shape spraying of complex internal and external geometries which eliminates the need for grinding. This is achieved by combining automatic, mass-flow controlled HVOF grit blasting with Nano-HVOF methods. The resulting coating displays an as-sprayed surface roughness of less than 2 μm Ra and a tight control over coating thickness and distribution. By carefully controlling the coating thickness and surface properties, it is possible to hone the required dimension and surface roughness.
Observation of Microstructures in Thermal Sprayed Coatings and Single Deposited Splats using Ion Beam Milling
Authors: Kim K. H. , Watanabe M. , Kuroda S. , Kawano N. 
Published: September 2022

Abstract
In this study, we investigated microstructures of thermal sprayed coatings and single deposited splats using two types of ion beam milling: one is argon ion beam for the cross-sectioning of thermal sprayed coatings in a cross section polisher, the other is gallium focused ion beam for the cross-sectioning and TEM sample preparation of single deposited splats. The cross section of WC-Co coatings fabricated by the polisher showed that it created a mirrored surface with minimizing artifacts such as pull-outs of ceramic particles or smearing of pores during conventional metallographic preparations. A thin and locally re-thinned membrane of single warm-sprayed nickel splat was feasible to observe the internal interface of particle/substrate in high resolution electron images. The substrate was heavily deformed by the impact of nickel particle with high kinetic and thermal energies. The particle and the substrate were intimately bonded without any voids or gaps.
Metastable Austenite Type Core Wire for Arc Spraying – Modeling of Heat Transfer in End Face and Coating Structure Analysis
Authors: Korobov Yu. , Filippov M. , Belozertsev A. , Neveszin S. , Shymiakov V. 
Published: September 2022

Abstract
Analysis of melting mode of core wire at Arc Spraying helped to explain a possibility of incomplete fusion of a charge of a core wire. Influence of physicochemical parameters of feedstock and atomization modes was established. Analysis results helped to develop a metastable austenite type Core Wire for Arc Spraying of good wear resistance. Applications results are shown.
Predicting the Thermal Conductivity of AlSi/Polyester Abradable Coatings: Effects of the Numerical Method
Authors: Bolot R. , Seichepine J. L. , Qiao J. H. , Coddet C. 
Published: September 2022

Abstract
The final target of this study was to achieve a better understanding of the behaviour of thermally sprayed abradable seals such as AlSi/polyester composites. These coatings are used as seals between the static and rotating parts in gas turbine applications. The machinability of the composite coatings during the friction of the blades depends on their mechanical and thermal effective properties. In order to predict these properties from micrographs, numerical studies were performed with different software packages such as OOF developed by NIST and TS2C developed at the UTBM. In 2008, differences were reported concerning prediction of effective thermal conductivity obtained with the two codes. In the present paper, it is shown that a particular attention must be paid to the mathematical formulation of the problem. In particular, results obtained with a finite difference method using a cell centre approach or a nodal formulation, allow explaining the discrepancies previously noticed. A comparison of the predictions of computed effective thermal conductivities is thus proposed for different codes and different meshing methods. This study is part of the NEWAC project, funded by the European Commission within the 6th RTD Framework program (FP6).
In Situ Observation of Impact Phenomena of Zirconia Molten Drops in Millimeter Scale Via Aerodynamic Levitator
Authors: Shinoda K. , Nagashio K. , Murakami H. , Kuroda S. , Kuribayashi K. 
Published: September 2022

Abstract
Spreading and rapid solidification behavior of millimeter-scale molten drops of 8 wt.% yttria-stabilized zirconia (YSZ) has been experimentally studied utilizing a novel splittable aerodynamic levitator (ADL). The focus was especially on the effect of initial undercooling on the splat formation. An YSZ sphere approximately 2.3 mm in diameter was levitated in a splittable ADL nozzle and melted by a carbon dioxide laser. The molten drop was dropped by splitting the ADL nozzle and impacted on a substrate 15 cm below at a speed of 1.7 m/s. The spreading and solidification behavior of the impacting drop was observed with a high-speed digital video camera. The undercooling of YSZ drops reached to more than 500 K at a containerless state, and the solidification rate was on the order of 1 m/s at this state. When drops were dropped at superheated states, the drop solidified after flattening completed. Meanwhile, when impacted at large undercooling, the drop spreading was suppressed by the solidification. Drastic difference was observed when a drop was impacted on a substrate covered with acetone liquid. The drop was splashing, recoiling, and rebounding despite fact that splashing would not occur at this impact condition.
Phase Composition and Microstructural Responses of Crystalline Mullite/YSZ Coating Under Water Vapor Environments
Authors: Garcia E. , Mesquita-Guimarães J. , Miranz P. , Osendi M. I. , Cojocaru C. V. , Wang Y. , Moreau C. , Lima R. S. 
Published: September 2022

Abstract
Mullite and mullite/ZrO2 bi-layer systems are being considered as environment barrier coatings (EBCs) for protection of Si-based (Si3N4, SiC) substrates against water vapor corrosion for application in forthcoming turbine engines. An approach to reduce the thermal expansion mismatch between mullite and ZrO2 layers in those coatings would be to tailor intermediate mullite/Y-ZrO2 composite layers. The feasibility of these composite layers is studied in a comparative manner by plasma spraying both single mullite and bi-layer coatings of mullite and of mullite/ Y-ZrO2 (75/25 vol %.) over Hexoloy SiC substrates. All feedstock materials are equally prepared using spray drying methods as the mix powders are not commercially available. Singular spraying conditions are used to assure enhanced crystallization of the mullite phase. Coatings are aged for 100 h at 1300 °C in a controlled water vapor environment. The effect of water corrosion on the exposed coatings is comparatively investigated, determining changes in crystalline phase by X-ray diffraction (XRD), the crystallization of amorphous phases is highlighted by the use of differential thermal analysis (DTA) tools and the microstructure of the polished coatings is analyzed by scanning electron microscopy (SEM).
Corrosion of Ti Coating Prepared by Modified HVOF Process
Authors: Deng C. M. , Deng C. G. , Liu M. , Huang J. , Zhou K. S. , Chen Z. K. , Wank A. , Schwenk A. 
Published: September 2022

Abstract
Titanium exhibits very good corrosion resistance property because of the formation of very dense oxide coating. Especially the good corrosion against Cl- solution for titanium material makes it wide applications in sea industry. It is very difficult to deposit titanium coating under atmospheric condition due to the strong affinity with oxygen and nitrogen especially in high temperature plume. Except the expensive LPPS process, much attention has been paid to the newly developed cold spraying. Unfortunately the stringent requirement for the starting power and low production efficiency limit the application of the cold spraying. A modified HVOF process was developed by reducing the outlet diameter of chamber and by directly introducing water into chamber, therefore lower plume temperature and higher chamber pressure than conventional HVOF process can be achieved. Attempts to deposit Titanium coating were carried out, and immersion of Titanium coated A3 steel into artificial seawater was performed in order to evaluate the density of as-sprayed Titanium coating. The results showed that dense Titanium coating could be obtained after parameter optimization and very few corrosion spot was observed on the surface of Titanium coated A3 steel after immersion into artificial seawater for 120 h.
Experimental Investigation of Fretting Wear on Nitrided and Thermal Spray Coated Ti-6-4 Parts for Lift Fan Applications
Authors: Patil P. , Sadeghi F. , Dixit S. , Dixit R. , Chin M. 
Published: September 2022

Abstract
The fretting phenomenon was investigated experimentally in contacts between nitrided, coated and nitrided-coated Ti-6-4 rods against uncoated M50 rods generating a circular Hertzian contact. A fretting wear test rig was designed and developed to facilitate mounting of rod specimens of different coating thicknesses. Fretting wear tests were performed on low temperature and high temperature nitrided Ti-6-4 rods as well as on T-800 (CoCrMoSi) thermal spray coated Ti-6-4 and T-800 coated M50 rods. Finally, tests were carried out on Ti-6-4 rods nitrided at low and high temperatures and T-800 thermal spray coated on the top. The results obtained from fretting tests of each surface against uncoated M50 are studied and compared. Fretting wear volumes and surface profiles are presented for the contacts studied. The fretting wear resistance of each surface is quantified and compared with Archard’s wear equation. The role of amplitude of motion and number of cycles on the fretting wear of coatings is discussed. It was observed that increase in fretting wear resistance of uncoated Ti-6-4 rods by nitriding is greater than thermal spray coating. The fretting wear resistance was found to be higher for high temperature nitrided-coated rods than for low temperature nitrided-coated rods.
Thermal Cycle Resistance of Oxidation-Resistant Metallic Coatings
Authors: Takahashi S. , Hatano M. , Kojima Y. , Harada Y. , Kawasaki A. , Ono F. 
Published: September 2022

Abstract
Thermal cycle resistance of Ni-20Cr, Ni-50Cr and CoNiCrAlY coatings manufactured by air plasma spraying was investigated according to a Japanese Industrial Standard "Testing method for thermal cycle resistance of oxidation resistant metallic coatings (JIS H 8452)” established in 2008. The specimens were exposed at 1000 °C and 1093 °C in air under cyclic heating and cooling condition up to 100 times. The thermal cycle resistance of oxidation-resistant metallic coatings was found to depend strongly on the testing temperature and the chemical composition of the coating materials. In the thermal cycle test at 1000 °C, the remarkable failure was not observed in any specimen. However, in the thermal cycle test at 1093 °C, although the Ni-20Cr coating caused the spalling on the whole surface of coating, the Ni-50Cr and the CoNiCrAlY coatings exhibited the excellent thermal cycle resistance even after applying the thermal cycles of 100 times, The CoNiCrAlY coating showed the mass gain with increasing the numbers of thermal cycle due to the preferential oxidation between the splats of the thermal spray particles. Furthermore, the failure behavior of specimens was investigated in detail by SEM, XRD and EPMA etc.
Research of Plasma Spraying Process of Nanostructured Zirconia Thermal Barrier Coating
Authors: Sun H. , Wang C. , Liu X. , Qu Z. , Bi J. 
Published: September 2022

Abstract
In this paper, the nanostructured zirconia thermal barrier coatings were prepared on GH3030 high temperature alloy surface by plasma spraying process. The nanostructured agglomerated ZrO2 feedstock was used as initial powders, and the NiCoCrAlY alloy as bond coating material. The relationship between bonding strength and spray current, secondary gas flow and spray distance were analyzed. The optimum parameters were acquired by orthogonal experimental design methods. The microstructures and phase structures of nanostructured zirconia thermal barrier coating were investigated thoroughly by SEM, TEM and X-Ray.
Effect of Temperature on Wear Characteristic of Cast Iron
Authors: Shaha S. K. , Haque M. M. , Dyuti S. 
Published: September 2022

Abstract
Conventional Fe-C-Si alloy cast iron shows good properties at low temperature but at high temperature its properties decrease very sharply. So, to protect this behaviour of cast iron, Si was replaced by Al, since both elements have similar graphitizing effect. In the present study, two types of cast iron, Fe-C-Si and Fe-C-Al, were cast in cold set resin bonded sand mould. After casting, the microstructures were studied using standard metallographic techniques. The wear tests were conducted using “CSM High Temperature Tribometer” following pin-on-disk method at 25 °C, 100 °C, 200 °C and 300 °C. The worn tracks were characterized using optical profilometer, SEM etc.. The results show that abrasive type wear was observed in both types of cast iron and always the Fe-C-Al cast has low wear rate compared to Fe-C-Si. However, after at 100 °C temperature, the wear resistance of Fe-C-Si cast iron starts to decrease whereas at lower temperature, it remains almost unchanged. The wear rates for Fe-C-Si alloy cast iron are 12.42, 16.51, 46.75 and 98.87x10-5mm3/N/m whereas the wear rates for Fe-C-Al cast iron are 3.32, 4.23, 4.40 and 8.15x10-5mm3/N/m at 25 °C, 100 °C, 200 °C and 300 °C, respectively.
Comparative Analysis of Anti-Cavitation and Abrasion Resistance Properties of two Different Detonation Coatings
Authors: Huang K.-F , Fang J.-P. , Wu S.-H. , Xu B. , Ye L. , Liu Z.-K. 
Published: September 2022

Abstract
Combined damage of cavitation and abrasion is one of the serious problems that affect lifetime and performance on hydraulic machineries and its components. Thermal spraying as a surface hardening and protection technology is required to protect hydraulic components, such as water turbine and radial flow pump, in general. Detonation sprayed coating with high abrasion resistance is one of the promising solutions as the protective coating against combined damage of cavitation and abrasion under solid-liquid double phase liquid conditions. In this study, NiCr-Cr3C2 and WC12Co coatings on the No.45 steel substrate surface have been formed by detonation spraying with the same technological parameter and their properties such as microstructure and microhardness have been studied. The cavitation and abrasion behavior of coatings and the substrate has been investigated using a self-manufactured rotating disk system. The resistance properties of cavitation erosion and abrasion have been illustrated and analyzed with the substrate by the cumulative mass loss curves. The results indicate that, the resistance properties of cavitation erosion and abrasion of NiCr-Cr3C2 coating are the best.
Degradation Mechanisms of Thermally Sprayed Coatings in Chloride Containing Electrolytes
Authors: Laurila J. , Niemi K. , Vuoristo P. 
Published: September 2022

Abstract
Thermally sprayed cermet coatings are widely used in pulp and paper industry and also in other applications of such corrosive conditions where chlorine is present. In these conditions corrosion resistance and wear resistance of the coatings are the most important characteristics. Corrosion resistance can be improved by sealing the corrosion sensitive base material surface under the coating from chlorine containing environment. Test materials in this work were thermally sprayed WC-10Co4Cr, Cr3C2-25NiCr and Sanicro 28 coatings prepared using HVAF and arc spray techniques. The degradation of the coatings and base material surface was characterized using micro hardness tests, optical and scanning electron microscopy, and also by conventional weight loss measurements. Wear resistance of the coatings was evaluated using modified rubber-wheel abrasion tests. In this work ASTM G48 corrosion testing standard was utilized in corrosion testing of these corrosion resistant thermally sprayed coatings. In demanding chlorine containing corrosion conditions it is essential to understand where the corrosion is concentrating in the structure. In the studied corrosion conditions Sanicro 28 and Cr3C2-25NiCr coatings were heavily corroded inside the coating material. Corrosion resistant Cr3C2-25NiCr cermet coating was corroded also between the coating and the base material and the adhesion between the base and the coating was lost in some of the specimens after one day exposure. Unexpectedly HVAF sprayed WC-10Co4Cr coating was giving the best performance of the coatings tested in this work.