bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle Treatment Modeling in a Time-Dependent D.C. Plasma Flow
Authors: Guenadou D. , Meillot E. , Saget A. 
Published: August 2022

Abstract
D.C. plasma spraying process leads to coatings with high level properties. The control of these properties implies to overcome well the process and in particular the interactions between the particles and the plasma plume. This latter shows high fluctuations outside the torch due to arc root movements on the anode wall inside the torch. These movements are responsible of less or more weak plasma flow stretching outside the torch and of air engulfment. From a simple numerical model based on the gas heating by JOULE effect in the anode, the realistic flow behavior is reproduced, in particular, the mechanisms of air engulfment into the plasma plume, such as it was described by PFENDER and al. Moreover, the centerline velocities and temperatures of the gas are compared with experimental values: the comparison shows good agreement. From this realistic flow, zirconia particle treatment modeling is carried on. Depending on the plasma plume stretching outside the torch and on particle granulometry, the particle trajectories and also velocities and temperatures present high variations, leading to particle thermocinetic states at impact quite different from one particle to the other.
Progress in Thermal Spray Processes
Authors: Nassenstein K. 
Published: August 2022

Abstract
Today, more than ever the greatest progresses are reached in the field of microprocessor technique. Electronic devices are becoming smaller and smaller and showing at the same time higher performance. This fact has an effect on equipment control in mechanical engineering. No equipment can be used economically without PLC and PC. Moreover, it is impossible to build one without using them. Since a long time electronic components like PLC are considerable reasonable in pricing compared to supposing simple mechanical or electro mechanical systems. At the same time higher recommendations are expected from operator and service persons. Thermal Spray guns and systems are in a steady further development. Beside the request for high power systems there is a demand coming up for smaller and more affordable systems. Nevertheless, high power plasma guns are also to be focused on due to the fact that there is still the demand for ceramic coatings on big components.
Characteristic of the Arc Length and Voltage in a DC Bi-Anode Plasma Torch
Authors: Gao Y. , An L.T. 
Published: August 2022

Abstract
A special bi-anode plasma torch has been developed for elongating the arc length and obtaining the arc with a fixed length. The relations between the arc voltage and the arc current were investigated for different gas compositions, and the effect of the gas flow rate on the arc voltage was also studied for the pure Ar plasma. The results show that for the pure Ar plasma, the arc voltage had a dropping characteristic for an arc with instable length and a rising characteristic arc voltage for an arc with fixed length, but for Ar-H2 plasma or Ar-N2 plasma, the arc voltage always had dropping characteristic. Increasing the gas flow rate will enhance the arc voltage both for an instable and fixed length arc.
Near-Net Shape Forming of Tungsten Material by Induction Plasma Deposition
Authors: Fan X. , Boulos M.I. 
Published: August 2022

Abstract
Induction plasma deposition has been applied in spray coating and near-net shape forming since long. In this paper, we present a few typical results in applying induction plasma spraying technique to fabricate the near-net shape tungsten components. With various shape, very thick, and large surface of W parts were fabricated, the microstructure in the bulk is uniform, and the density is greater than 98% theoretical density.
Investigation of Relationship Between Spray Parameters And Al2O3 Coating Properties Controlled by On-Line Monitoring System
Authors: Kanno A. , Sugiura H. , Takeuchi J. 
Published: August 2022

Abstract
The technique was examined to prevent errors during thermal spraying by setting up a spray on-line monitoring system (Spray Watch-2i System) at the starting position in the production line using plasma spraying, and monitoring the characteristics of the particles in the plasma flame between each spraying cycle. The tests were carried out with several spray conditions, changing the gas flow, and the arc current. The state of the plasma flame was measured as the velocity, temperature and flux density of the flying particles. The coating properties were then evaluated by measuring the dielectric breakdown test. It has been found that the evaluation result of the coating correlates very well with the monitoring results of the flame particle characteristics. Therefore there is a possibility that monitoring the state of the particle characteristics within the flame during spraying can control the coating characteristics comparatively easily.
Photocatalytic Decomposition of Nitrogen Oxides Over TiO2 Coatings Elaborated by Liquid Feedstock Plasma Spraying
Authors: Toma F.-L. , Bertrand G. , Klein D. , Coddet C. , Meunier C. 
Published: August 2022

Abstract
In this paper, the modified method of plasma spraying using liquid suspension feedstock was used to elaborate thin titanium dioxide coatings. TiO2 Degussa P25 powder were dispersed by continuous stirring in distilled water and alcoholic solutions and injected in an Ar-H2 or Ar-H2-He plasma plume under atmospheric conditions. Scanning electron microscopy and X-ray diffraction were performed to study the microstructure and crystalline phases of titanium dioxide coatings. The anatase content in the elaborated TiO2 deposits strongly depended on the type of the suspension solvent. The photocatalytic activity of the titanium dioxide coatings was evaluated from the conversion rate of nitrogen oxides and compared with that of the initial powder. The obtained results allowed to affirm that the method of the liquid plasma spraying proved to be a promising technique to elaborate photocatalytic TiO2 coatings for the removal of nitrogen oxides pollutants.
RF Plasma Deposition of Half-Cell (Anode – Electrolyte) Assembly of Medium Temperature Planar Solid Oxide Fuel Cell
Authors: Jia L. , Gitzhofer F. 
Published: August 2022

Abstract
The system studied in this work is based on a Gadolinia-doped Ceria (GDC) matrix and a Nickel oxide cermet as the anode material where both layers are RF plasma deposited. The challenge lies in the optimization of the anode deposition parameters to obtain a controlled porosity thick layer and to process the electrolyte material in such a way as to completely eliminate both open and closed porosity in the relatively thin deposit. The starting materials were nitrate based solutions, prepared so as to obtain final anode spray deposits of NiO-GDC (35%Wt) with the aimed for electrolyte composition of Gd0.2Ce0.8O1.90. In order to optimize these anode deposits, the plasma power, the “stand off” distance, the concentration of the salts solution, as well as substrate cooling, were studied. Similar parameters were also studied for the electrolyte deposition process but, in order to assure attaining high deposit density, the supersonic RF torch nozzle was used for the spray processing. The interactions between all of these parameters and their influence on the deposition process, for both the anode and the electrolyte layers, is examined and discussed.
Advanced Nanoscale Neutron Absorber Coatings for Safe Longterm Storage of Spent Nuclear Fuel and Nuclear Waste
Authors: Branagan D. , Buffa J. , Maston M. 
Published: August 2022

Abstract
Neutron absorbers are expected to play an important role in the long-term storage of spent nuclear fuels and nuclear wastes. High neutron absorbing capability, long-term stability, and the capacity to stay with the fuel are important criteria in preventing critical conditions during possible waste package degradation in geological time frames. Existing available neutron absorbing materials are based on boron or boron-10 isotope modifications of austenitic stainless steels or to aluminum based metal matrix composites. Specific rare earths such as gadolinium, samarium, or europium are found to have much higher thermal neutron cross section than boron or boron-10 but have high reactivity which limit their stability and ultimate applicability. In this paper, it is described how it is possible through a nanotechnology approach, to overcome the solubility and stability limitations of conventional materials to allow incorporation of high amounts of boron and rare earths into advanced HVOF coatings. During the development of the NeutraShieldTM Coatings, it was found that high fractions of rare earth elements such as gadolinium along with high concentrations of boron could be dissolved in the liquid melt and then remain soluble in the metallic glass structure. During the transformation of the glass to the nanocomposite structure, the rare earths are found to come out of supersaturated solid solution to form stable nanoscale ternary intermetallic R2Fe14B phases which form in a commensurate fashion and is protected by the highly noble matrix. Abstract only; no full-text paper available.
Self Propagating High Temperature Synthesis of Aluminium-Matrix-Composite Coatings by Means of Atmospheric Plasma Spraying
Authors: Bach Fr.-W. , Möhwald K. , Wenz T. 
Published: August 2022

Abstract
An important growth potential in thermal spraying industry consists of the development of new coating materials. Metal- or Ceramic-Matrix-Composites (MMC / CMC) are of special interest due to a variety of properties which can be influenced particularly by the ratio of matrix and reinforcing material. Thermal sprayed coating properties mainly depend on thermal and kinetic energy of the spray particles. An increase in thermal energy of sprayed particles can be obtained by Self Propagating High Temperature Synthesis (SHS) reaction between components of the spray material. Hence a higher adhesive strength, a lower porosity and an increased deposition efficiency can be expected. Aluminium-based spray materials, containing metal oxides, are suitable for the Self Propagating High Temperature Synthesis to produce MMC-coatings. For good contact between the reactants, powders of aluminium and chromium oxide for plasma spraying were prepared by mechanical alloying. Coatings characterization results on the base of optical microscopy, scanning electron microscopy (SEM), X-ray structure analysis (XRD) and measurements of velocity and temperature with a DPV2000 system. The plasma spraying process combined with SHS reaction of the spray material leads to raised enthalpy of spray particles combined with an increased ad-/cohesive strength and a lower porosity as well as an increased deposition efficiency.
The Influence of Spraying Parameters on In-Flight Characteristics of Tungsten Particles and the Resulting Splats Sprayed by Hybrid Water-Gas Stabilized Plasma Torch
Authors: Matejicek J. , Chumak O. , Konrad M. , Oberste-Berghaus J. , Lamontagne M. 
Published: August 2022

Abstract
Tungsten particles were sprayed by a novel plasma torch with hybrid water-gas stabilization (WSP®-H). Several spraying parameters were varied – arc current, argon flow rate, carrier gas flow rate and spraying distance. The temperature and velocity of the individual particles were monitored by the DPV 2000 optical sensor. Individual splats were collected on polished stainless steel substrates and analyzed by SEM to assess their melting, flattening and/or fragmentation. These features were correlated with the basic in-flight particle characteristics and conditions for production of dense coatings were sought for. Significant dependence of the splats morphology on spraying parameters was found, and important improvement of particle melting at WSP-H over conventional water stabilized plasma torch (WSP) was registered.
Aerodynamic Characteristics of High-Velocity Oxy-Fuel Thermal Spray Process
Authors: Katanoda H. , Matsuoka T. , Kuroda S. , Kawakita J. , Fukanuma H. , Matsuo K. 
Published: August 2022

Abstract
A special HVOF gun is used for aerodynamic research on internal flows of gas and particles in HVOF gun. The gun has rectangular cross-sectional area and has sidewalls of optical glass or transparent acrylic resin. Compressed air is used as process gas instead of combustion gas to visualize internal flow of the gun. The high-speed gas flows including shock waves in the gun are visualized by Schlieren technique. Particle trajectories in the gun are also visualized by high-speed digital video camera. The observation of erosion pattern created by particle collision on the barrel wall helps understand the particle trajectories throughout the barrel.
Real Time Control for Plasma Spray: Sensor Issues, Torch Nonlinearities, and Control of Coating Thickenss
Authors: Gevelber M. , Cui C. , Vattiat B. , Fieldman Z. , Wroblewski D. , Basu S. 
Published: August 2022

Abstract
Real-time control offers the potential to reduce plasma spray variations that affect yield and coating quality. Important factors for designing such controllers are discussed including dominant nonlinearities, cross-coupling interactions, and sensor issues. The performance of several alternative strategies to achieve better coating thickness control are evaluated.
On the Measurement of Substrate Temperature During Thermal Spraying
Authors: Moulla L. , Salhi Z. , Planche M.P. , Cherigui M. , Coddet C. 
Published: August 2022

Abstract
Substrate temperature is nowadays recognized as a key parameter to optimise the coating quality in the thermal spraying process. Generally parts being processed are in motion and therefore non contact temperature measurement devices are appropriate. In contrast to thermocouples, optical pyrometers have several advantages. First, they are easy to install and second they do not bring any disturbance to the measured system. Meanwhile, several problems may arise with those devices which are not always considered as they should be and in particular the variation of material emissivity temperature, the effect of the reflection of the external radiation or the attenuation of the optical signal due to the variable transmissivity of the optical path. The aim of this work was to develop algorithms for correcting optical pyrometer temperature measurements during thermal spraying by taking into account emissivity variations and radiation reflexion on the components. Emissivity of some materials with respect to the specific spectral band of the pyrometer and the influence of reflected radiations were measured. Results are discussed in order to point out the influence of each parameter on the temperature value.
Development of Highly Molten Chloride Corrosion Resistant Coatings Assisted by Mechano-Chemical Reaction
Authors: Ichikawa Y. , Ogawa K. , Shoji T. , Solonenko O.P. 
Published: August 2022

Abstract
In waste-to-energy power generation plants, increasing the combustion temperature improves plant efficiency. However, due to problems caused by molten chloride corrosion, the combustion temperature cannot be increased. Consequently, in order to increase the temperature, it is first necessary to protect components from molten chloride corrosion. In this study, CoNiCrAlY coating is proposed as a protective film against molten chloride corrosion. Three kinds of specimens were prepared. One was standard coating made from conventional CoNiCrAlY. The others included the addition of Mo to the CoNiCrAlY by two different techniques. One technique is mechanical alloying (MA), and the other is a gas-atomizing technique. The mechanic-chemical reaction that occurs during the mechanical alloying process can be expected to create new functionality for the material. The effect of Mo content was evaluated for corrosion resistance. These specimens were coated by low pressure plasma spraying (LPPS). The specimens were exposed to NaCl-KCl for the molten chloride corrosion test. The results of the corrosion tests show that corrosion resistance improved in only MA CoNiCrAlY coatings. These results reveal that mechanically alloyed CoNiCrAlY-Mo coating has excellent corrosion resistance, and its corrosion resistance behavior is different from that of gas-atomized CoNiCrAlY-Mo.
Experimental Investigation of Influence of Plasma Spraying Operational Parameters on Properties of Hydroxyapatite
Authors: Dyshlovenko S. , Pawlowski L. , Roussel P. 
Published: August 2022

Abstract
Excellent biocompatibility of hydroxyapatite (HA) is the main reason of application plasma-sprayed coatings onto orthopedic prostheses. A careful optimization of spray parameters is necessary to avoid thermal decomposition of HA onto less biocompatible products such as e.g. tricalcium phosphate, tetracalcium phosphate, calcium oxide and amorphous calcium phosphates. The spray parameters influence considerably the decomposition and the present study is devoted to understand this influence using on an experimental way. The design of experiments (DOE) was made using two-level 2N plan of experiments (N=5). In total, 32 experiments of spraying were carried out by varying following operational parameters: (i) composition of plasma working gases; (ii) electric power input; (iii) art of spraying (into water or onto substrate); (iv) carrier gas flow rate and; (v) art of injection (external and internal). Plasma-sprayed coatings and powders were analyzed by Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The X-ray diagrams enabled to find the content of crystal phases. The content was a first response function described by a polynomial regression equation. The morphology of obtained deposits was also characterized using Scanning Electron Microscope (SEM). Their porosity was estimated using image analysis of coatings cross section images.
Oxidation Study of High Temperature Ti Compatible Abradable Seal
Authors: Fiala P. , Chilkowich A.P. , Hajmrle K. , Shiembob L. 
Published: August 2022

Abstract
The goal of this paper is to evaluate high temperature ageing properties of a new high temperature titanium blade compatible abradable material DurabradeTM 2614. Coatings were tested in as-sprayed condition and after ageing at 550°C and 655°C for up to 8,030 hours. Coating properties such as coating hardness, erosion resistance, and cohesive strength were evaluated at regular time intervals. Abradability was tested in as-sprayed condition and after ageing. The results show that coating hardness, GE erosion resistance, and cohesive strength of the new material change most in the first 200 hours and SMC90 erosion resistance, and oxidation weight gain change most in the first 1,000 hours and then they stabilize at values that guarantee good seal performance. The good performance of the new seal after 8,030 hours ageing has been demonstrated by abradability and erosion testing.
Plasma Sprayed Cast Iron Coatings Containing Solid Lubricant Graphite and H-BN Structure
Authors: Tsunekawa Y. , Ozdemir I. , Okumiya M. 
Published: August 2022

Abstract
Water atomized cast iron powder of Fe-2.17C-9.93Si-3.75Al (in wt%) were deposited onto an aluminum alloy substrate by atmospheric DC plasma spraying to improve its tribological properties. Pre-annealing of the cast iron powder allows to precipitate considerable amounts of graphite structure in the powder. However, significant reduction in graphitized carbon in cast iron coatings is inevitable after plasma spraying in air atmosphere due to the in-flight burning and the dissolution into molten iron droplets. Hexagonal boron nitride (h-BN) powders which have excellent lubricating properties like graphite were incorporated to the cast iron powder as solid lubricant by sintering process (1300 °C) to obtain protective coatings with low friction coefficient. The performance of each coating was evaluated using ring-on-disk type wear tester under paraffin base oil condition in air atmosphere. Conventional cast iron liner which has flaky graphite embedded in pearlitic matrix was also tested in similar conditions in order to make a comparison. Sections of worn surfaces and debris were characterized and wear behaviour of plasma sprayed coatings are discussed.
Microstructure and Properties of Nanostructured WC/Co Coating Deposited by Supersonic Plasma Spraying
Authors: Ma S. , Li C. , Ye X. 
Published: August 2022

Abstract
Nanostructured and conventional WC/Co coatings were prepared by supersonic plasma spraying process respectively. The bonding strength, microhardness, tribological characteristics such as friction coefficient and wear resistance, microstructure and the phase ingredient were studied. The result of the XRD suggests that the coating contains low-carbon phase. TEM analysis reveals that WC phase with the dimension of about 100nm is dispersed in the nanostructured coating. Results of mechanical and tribological properties tests show that nanostructured coating has better performance in comparison with conventional one, with increase of about 40% in the bonding strength, 3% in the microhardness, 14% in the wear resistance, and a decrease of 0.06 in friction coefficient, respectively. After tribological properties tests, obvious plastic deformation was observed on the wear trace surface of the nanostructured coating, while microcrack existed on the surface of conventional coating. Superfine grain strengthening is the primary reason that enhances the performances of the coating.
Corrosion and Tribological Behaviour of Polyamide-Nitride Composite Coatings
Authors: Guilemany J.M. , Fernández D. 
Published: August 2022

Abstract
Over the last years, interest in thermally sprayed polymer coatings has increased. They have excellent corrosion and chemical resistance properties. Unfortunately, they have some limited properties like scratch and wear resistance. Fillers can be a good solution to improve these properties. In the Thermal Spray Centre of Barcelona, blends of polyamide powder with different contents of boron and silicon nitride have been flame-sprayed and studied. Microstructural characterisation of the composite coatings has been done using Optic and Scanning Electron Microscopies. Wear resistance has been evaluated by means of Ball on Disk (ASTM G99-90) and Rubber Wheel (ASTM G65-91) tests. Salt Spray Fog tests (ASTM B117-90) have been performed in order to evaluate their corrosion resistance.
Fractographic Approach to Wear Mechanisms of Selected Thermally Sprayed Coatings
Authors: Nohava J. , Enzl R. , Zahalka F. , Foucher C. 
Published: August 2022

Abstract
Coatings deposited by thermal spraying are widely used for applications where enhanced resistance to wear is a crucial factor. In this work we focused on HVOF and plasma sprayed WC-Co, NiCrSiB, Cr3C2-NiCr, AISI 316L and Cr2O3 coatings. The materials were examined by wet slurry abrasion tests, microhardness and roughness measurements. Systematic fractographic analysis in SEM was devoted to determine the main failure mechanisms of selected coatings. The WC-Co coating exhibited the lowest wear rate while 316L coating exhibited the highest wear rate. The plasma sprayed Cr2O3 coating exhibited wear rate higher than HVOF sprayed cermet coatings but lower than metal coating. In most cases it was found that the higher microhardness, the higher is the wear resistance of the coating. The most favorable microstructure was found to be a mixture of hard particles dispersed in tough metal matrix. Matrix-like structure and internal splat microstructure were the main factors controlling the wear resistance of the investigated HVOF and WSP coatings.