bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of the In-Flight Particles Characteristics Using Neural Networks and Analytical Model
Authors: Kanta A.F. , Planche M.P. , Montavon G. , Coddet C. 
Published: September 2022

Abstract
In thermal spray process, the in-flight particle characteristics such as particle size, velocity and temperature influence significantly their flight duration as well as their melting degree. Consequently, they influence the splat formation and ultimately the coating properties. Thus, the knowledge of the interactions between the process parameters and the in-flight particle characteristics is very important for optimizing the coating properties. Artificial Neural Network (ANN) concept was used to predict in-flight particle velocity and temperature considering the case of alumina (Al2O3-TiO2) coatings. Databases of in-flight particle characteristics (diameter, velocity and temperature) versus spray process parameters (arc current intensity, hydrogen rate and plasma gas composition) were collected. ANN was trained with the database to establish the relationships linking the particle diameter and spray process parameters to particle velocity and temperature. Then, the established ANN relationships permitted to determine the inflight particle velocity and temperature versus their diameter for given spray process parameters. These velocity and temperature data were then used to determine the time for complete particle melting and the particle dwell-time before impact by an analytical model for given operating conditions.
Mathematical Modeling of Coating Under Shock Loading of Nanopowder Layer
Authors: Kiselev S. , Kiselev V. 
Published: September 2022

Abstract
A procedure for calculating the adiabat of copper nanopowder is developed. The nanopowder adiabat was determined from numerical calculations at the nano-level performed by the molecular-dynamics method. With the use of this procedure, the problem about copper nanopowder compaction in a metal container under the action of an oblique shock wave was addressed. The temperature rise behind an oblique shock wave in the nanopowder is two orders of magnitude greater than in the micropowder.
Predicting Splat Morphology in a Thermal Spray Process
Authors: Dhiman R. , Chandra S. 
Published: September 2022

Abstract
Splats formed during a thermal spray process may be either highly fragmented or intact and disk-like. To predict this change in splat morphology, a dimensionless solidification parameter (Θ), which takes into account factors such as the substrate temperature, splat and substrate thermophysical properties, and thermal contact resistance between the two, has been defined. Θ is the ratio of the thickness of the solid layer formed in the splat while it is spreading, to the splat thickness. The value of Θ can be calculated from simple analytical models of splat solidification and spreading. If the solid layer growth is very slow (Θ &lt;&lt; 1), the droplet spreads out to a large extent. Once it reaches maximum spread it becomes so thin that it ruptures, producing fragmented splats. If, however, the solid layer thickness is significant (Θ ~ 0.1 – 0.4), the droplet is restricted from spreading too far and does not become thin enough to rupture. Under such circumstances, disk-type splats are expected. When the solid layer growth is rapid (Θ~1), spreading of the droplet is significantly obstructed by the solid layer, producing splats with fingers around their periphery. Predictions from the model are compared with experimental data.
Numerical and Experimental Study of Ni-Particle Impact on a Ti-Surface
Authors: Bahbou M.F. , Choquet I. , Nylén P. 
Published: September 2022

Abstract
The impact of plasma sprayed sieved Ni-5%Al particles on a titanium substrate was investigated. The particles had a narrow diameter range (-65 + 75 µm), and a speed and temperature just prior to impact of about 100m/s and 2400°C, respectively. These powder particles were sprayed on two sets of polished titanium alloy surfaces. One set was a non-oxidized surface and the other one was a previously oxidized surface at 600°C for two hours. Resulting splats were characterised experimentally by infrared pyrometry and scanning electron microscopy. The effects of the substrate’s oxide layer on the shape of the splat, also on the cooling rate and flattening speed during impact were studied and discussed. This problem is also being investigated numerically. A first step was devoted to the selection of relevant simulation parameters. Test cases to study qualitatively the effect of surface oxidation through parameters such as the contact angle and thermal contact resistance are in progress. They will be compared to the experimental results.
A New Concept of the Application of Shock Wave Technology in the Cold Gas Dynamic Spray Process
Authors: Bobzin K. , Lugscheider E. , Nickel R. , Parkot D. , Varava W. , Olivier H. , Luo X. 
Published: September 2022

Abstract
A new cold spray process for a combustion-free spraying is studied experimentally and by modeling and simulation. The high particle velocity at the front of the substrate is achieved by using the shock tube technology. The particles have been injected downstream of the nozzle throat into a supersonic nozzle flow. The shock tube of 6.5 m length and 56 mm inner diameter provides the necessary reservoir conditions for the nozzle flow. The measurements of the particle velocity made by a laser Doppler anemometry (LDA) setup showed that the maximum velocity amounts to 1220 m/s for stainless steel particles of 15 µm diameter. The CFD-Code (Fluent) is first verified by a comparison with available numerical and experimental data for gas and gas-particle flow fields in a long Laval-nozzle. The good agreement implied the great potential of the new dynamic process concept for cold gas coating applications. Then the flow fields in the short Laval nozzle designed and realized by the Shock Wave Laboratory (SWL) have been investigated. The gas flow for experimentally obtained stagnation conditions has been simulated. The gas-particle flow without and with the influence of the particles on the gas flow has been calculated by the Surface Engineering Institute (IOT) and compared with experiments. The influence of the injection parameters on the particle velocities has been investigated as well.
Simulation on Controllable-Porosity Coating by Plasma Spray
Authors: Zhang H.O. , Hu B.Y. , Wang G.L. 
Published: September 2022

Abstract
A new method was introduced to fabricate porous coating and to control its porosity by changing spray parameters. Two models were constructed to simulate the deformation of molten particle and the deposition process of splats on substrate. Considering the gap-pore, step-pore and shield-pore in the presented models, the influence of spray angle on the porosity of coating was mainly investigated. Besides, other spray parameters which influence porosity were analyzed, including the velocity of spray gun, particle velocity and particle size. Moreover, a new forming method of graded porous coating is discussed.
Influence of Droplet Breakup and Collision in the Solution Precursor Plasma Spraying Process
Authors: Shan Y. , Coyle T.W. , Mostaghimi J. 
Published: September 2022

Abstract
Finely structured ceramic coatings can be obtained by solution precursor plasma spraying. The final structure of the coating highly depends on the droplet size and velocity distribution at the injection, the evolution of the spray in the jet, and droplet breakup and collision within the spray. This paper describes a 3D model to simulate the transport phenomena and the trajectory and heating of the solution spray in the process. O’Rourke’s droplet collision model is used to take into account of the influence of droplet collision. The influence of droplet breakup is also considered by implementing TAB and Wave droplet breakup models into the plasma jet model. The effects of droplet collisions and breakup on the droplet size, velocity, and temperature distribution of the solution spray are investigated. The results indicate that droplet breakup and collision play an important role in determining the final particle size and velocity distributions on the substrate.
Fast Modeling of Phase Changes in a Particle Injected Within a dc Plasma Jet
Authors: Ben Ettouil F. , Pateyron B. , Ageorges H. , El Ganaoui M. , Fauchais P. , Mazhorova O. 
Published: September 2022

Abstract
When spraying ceramic particles with a low thermal conductivity such as zirconia using Ar-H2 direct-current (d.c.) plasma jets where the heat transfer is important, heat propagation phenomena take place with the propagation of melting, evaporation or even solidification fronts. Most models neglect these heat propagation phenomena assuming the particle as a lumped media. This work is aimed at developing a model coupling the effect of heat propagation with the particle dynamic within plasma jets. It uses an adaptative grid in which the coordinates of the phase change fronts are fixed. It allows minimizing the calculation costs (approximately 10 seconds on PC under windows XP against 1hour with an enthalpy model). Such calculations are illustrated for dense and porous agglomerated zirconia as well as iron particles which evaporation in an Ar- H2 (25 vol %) plasma is important.
Effect of Microstructure of HVOF-Sprayed WC-Co Coatings on Their Mechanical Properties
Authors: Chivavibul P. , Watanabe M. , Kuroda S. 
Published: September 2022

Abstract
Twelve commercially available WC-Co powders with different average carbide sizes (0.2, 2, and 6 µm) and cobalt contents (8, 12, 17 and 25 wt.%) were sprayed on carbon steel substrates using High Velocity Oxy-Fuel (HVOF) spraying Characterization of the coatings showed that the average carbide sizes and carbide volume contents in the coatings were lower than those of feedstock powders. Hardness and fracture toughness of the coatings were investigated using indentation techniques. Young’s modulus was measured by an ultrasonic technique. The hardness and Young’s modulus decreased with increasing cobalt content, while fracture toughness slightly increased. The effect of carbide size on the hardness showed no specific trend. These behaviors were discussed with the help of microstructure observations of the coatings by scanning electron microscopy, X-ray diffraction and chemical analysis. Using an improved HVOF process with a gas shroud could result in less decomposition of the powder and higher fracture toughness.
Optimization of a Rotating Twin Wire-Arc Spray Gun
Authors: Bolot R. , Liao H. , Mateus C. , Coddet C. , Bordes J.M. 
Published: September 2022

Abstract
The replacement of cast iron sleeves through thermal spray coatings is an interesting alternative to improve the inter bore reliability, to reduce weight and to reduce the inter bore distance for automotive engines. Most of the actual production and pilot equipments use the ROTAPLASMA process to provide such functional coatings. However, the wire-arc spray process may often present different advantages like a higher deposition rate and a lower cost of the produced coatings. The LDS (Lichtbogendrahtspritzen) technology developed by DaimlerChrysler is a wire-arc process working with two wires whereas the PTWA (Plasma Transferred Wire Arc) process designed by Flame Spray Industries and the Ford Motor Company use a single wire. The present paper shows that the wire-arc technology may replace efficiently the APS (Atmospheric Plasma Spray) for the generation of thermally sprayed coatings applied on engine cylinder bores. A first rotating wire-arc spray system was previously designed and tested a few years ago. The present paper shows how computational fluid dynamic (CFD) may help in solving industrial problems: the FLUENT CFD code was used in order to perform improvements of the initial gun design.
Plasma-Sprayed Calcium Oxide Stabilized Zirconia Coatings for Biomedical Application
Authors: Wang G.C. , Liu X.Y. , Ding C.X. 
Published: September 2022

Abstract
Calcium oxide stabilized zirconia coatings have been deposited onto Ti-6Al-4V substrates by means of atmospheric plasma spraying and incubated in the simulated body fluid for different periods of time to investigate the formation of apatite on their surface. The phase composition and microstructure of the coatings before and after immersion were examined by scanning electron microscopy and X-ray diffraction. The results obtained showed that apatite can be formed on the coating soaked in SBF solution, which indicated that calcium oxide stabilized zirconia possessed good bioactivity.
In Vitro Durability of Titanium/Dicalcium Silicate Composite Coatings
Authors: Xie Y.T. , Zheng X.B. , Liu X.Y. , Ding C.X. 
Published: September 2022

Abstract
Titanium/dicalcium silicate composite coatings with different ratios (weight ratios as Ca2SiO4: Ti = 3:7, 5:5, 7:3) were prepared by plasma spraying. Effects of titanium addition on coating properties, such as bonding strength, Young’s modulus and dissolution in simulated physiological environment, were studied. Results showed that the bonding strength between coating and Ti-6Al-4V substrate increased with increase of titanium content in the composite coatings. It was explained by the narrowed dissimilarity of thermal expansion coefficients between the coatings and substrates. Degradation of mechanical properties after immersion in simulated body fluid was also studied. The dissolution of dicalcium silicate in the composite coatings resulted in the decrease of bend strength and Young’s modulus of the coatings in the simulated physiological environment. The higher titanium content in the composite coatings, the stabler are the composite coatings in the physiological environment.
Progress in Plasma Sprayed Bioceramic Coatings
Authors: Ding C. 
Published: September 2022

Abstract
Plasma sprayed hydroxyapatite coating can bond to living bony tissue, and it is being widely used in clinical application. The problem of hydroxyapatite coating on metal substrate may mainly come from the instability of coating-substrate interface and the unstable duration of coating in the presence of body fluid. Therefore, it is desirable to develop newly bioactive coatings with good bioactivity and mechanical properties. In this paper, new progress in plasma sprayed bioactive coatings at Shanghai Institute of Ceramics are reviewed. The novel coatings including wollastonite, dicalcium silicate, diopside and titania were deposited. All the bioactive coatings mentioned above form a bone-like apatite layer on their surface immersed in simulated body fluid, indicating their good bioactivity. The formation of bone-like apatite is induced by Si-OH and Ti-OH on the surface of coatings. The results of cell culture test indicated that novel coatings can enhance osteoblast adhesion, proliferation and differentiation, indicating their good biocompatibility.
Properties and Performance of High Purity Thermal Barrier Coatings
Authors: Xie L. , Dorfman M.R. , Cipitria A. , Paul S. , Golosnoy I.O. , Clyne T.W. 
Published: September 2022

Abstract
It was found that the content of impurity oxides in 7YSZ, such as SiO2 and Al2O3, has a significant effect on the coating sintering resistance and phase stability of 7YSZ thermal barrier coatings (TBCs). The reduction of the impurity content will significantly improve the sintering resistance and phase stability of 7YSZ TBCs and thus allow the 7YSZ TBCs to be used at higher temperatures.
Evaluation of Adhesion/Cohesion of Plasma Sprayed Ceramic Coatings by Scratch Testing
Authors: Ding C.X. 
Published: September 2022

Abstract
Plasma sprayed ceramic coatings have been widely applied in modifying surface properties of metal components. They are useful to prevent various types of wear, corrosion, erosion and thermal degradation, thereby extending components service life and reducing the need for expensive and repetitive maintenance. The durability and functionality of plasma sprayed ceramic coatings is critically dependent on the adhesion between the ceramic coating and the underlying substrate as well as the cohesion between splats. In this work, both nanostructured and conventional Al2O3 coatings were prepared by atmospheric plasma spraying technology (APS). For each feedstock, four kinds of coating samples deposited under different spraying parameters were designed, and moreover, seven groups of conventional coatings with different thickness were deposited under the same spraying parameters. Adhesion/cohesion of the plasma sprayed Al2O3 coating samples were evaluated by scratch testing. The results obtained reveal that the spraying parameters have strong influences on the microstructure of plasma sprayed Al2O3 coatings, which in turn influence their properties including deposition efficiency, porosity, microhardness as well as adhesion/cohesion.
Evaluation of APS YPSZ Powder and Coating Homogeneity: XRD and Raman Spectroscopy Studies
Authors: Lawson K.J. , Ritchie L.J. , Xie L. , Dorfman M.R. 
Published: September 2022

Abstract
The monoclinic and tetragonal phase compositions and distribution in air plasma sprayed (APS) yttria-partially stabilized zirconia (YPSZ) thermal barrier coatings were studied. The coatings were produced from powders with varying phase concentrations, chemical purity and powder production processes. Both the powder and coatings were characterized using X-ray diffraction (XRD) and Raman spectroscopy. The use of environmental scanning electron microscopy (ESEM) and X-ray energy dispersive analysis (EDS) added morphological and elemental information to the study. XRD and Raman spectroscopy were shown to be powerful combined tools and shows an overall decrease in the monoclinic phase within the coatings produced from the different powders. The distribution of both the monoclinic and the tetragonal phases could be highlighted both in the coatings and the individual powder particles. This indicated changes in monoclinic concentration in the less dense areas of some of the coatings and a varying distribution across particles in some of the powders. Raman mapping over small areas also showed how phase surface distribution, on the coatings surfaces, could be assessed.
Zircon-Based Ceramics Composite Coating for Environmental Barrier Coating
Authors: Suzuki M. , Sodeoka S. , Inoue T. 
Published: September 2022

Abstract
Studies on plasma spraying of zircon (ZrSiO4) have been carried out by the authors as one of the candidates for an environmental barrier coating (EBC) application, and had reported that substrate temperature is one of the most important factors to obtain crack-free and highly-adhesive coating. In this study, several amount of yttria were added to zircon powder, and the effect of the yttria addition on the structure and properties of the coatings were evaluated in order to improve the stability of the zircon coating structure at elevated temperature. The coatings obtained were composed of yttria stabilized zirconia (YSZ), glassy silica, while the one prepared from monolithic zircon powder composed of the metastable high temperature tetragonal phase of zirconia and glassy silica. After the heat treatment over 1473K, silica and zirconia formed zircon in all the coatings. However, the coatings with the higher amount of yttria had less amount of zircon formed. This resulted in the less open porosity of the coating at elevated temperature. These yttria added coatings also showed good adhesion even after the heat treatment, while monolithic zircon coating had peeled off.
Properties of HVOF Sprayed Ferrous Coatings for Corrosion Protection
Authors: Bobzin K. , Lugscheider E. , Ernst F. , Hidalgo G. , Zwick J. 
Published: September 2022

Abstract
The increase of commodity prices for classical corrosion protection materials such as WC/Co and Cr3C2/NiCr are leading to significantly increased coating costs. This reduces the competitiveness when compared to other coating technologies such as electroplating, particularly if carbide coatings are representing an over engineered solution for the considered application. A promising economic alternative is the employment of advanced ferrous materials. Fe-base coatings have the potential for very good corrosion protection and favourable wear properties combined with a low cost level due to relatively low priced alloy materials. In this study three different Fe-base materials have been sprayed by liquid and gaseous fuel HVOF spraying and analysed with respect to microstructure, hardness and corrosion resistance. Corrosion tests have been carried out with sulphuric acid as well as artificial seawater.
Corrosion Behavior of Arc Spraying Nickel Based Coating
Authors: He D.-Y. , Dong N. , Jiang J.-M. 
Published: September 2022

Abstract
In this paper, Ni-based cored wires were prepared by using NiCr strip to wrap metal powders of Ni, Cr, Mo, CrB. Ni-based coatings were prepared by electric arc spraying process. The microstructures of Ni-Cr-Mo and Ni-Cr-B coatings were investigated by means of scanning electron microscopy (SEM) and energy-dispersive analysis (EDAX) and X-ray diffraction (XRD) analysis. The coatings have compact surface and presented the bonding strength higher than 40MPa. Corrosion-resistance performance of coatings was evaluated by salt-spray- test and electrochemical corrosion test. The results showed that Ni-based coatings containing Mo (5%) element or B element (2-4%) had better anti-chlorine ion corrosion performance than that of Ni-based coatings without Mo element, and PS45 (Ni-Cr-Ti) coating. The anti-chlorine ion corrosion coatings could be used for resolving the corrosion protection problem of the equipments and piping contacting sour, alkali, salt liquid in the petrochemical engineering.
Development and Application of DZ9000E Portable HVOF System
Authors: Wang R.J. , Xu L. , Zhang T.J. , Huang X.O. , Luo H.J. 
Published: September 2022

Abstract
Comparing with the traditional liquid oxygen and kerosene HVOF system (LHVOF), the development of the DZ9000E Oxygen Gaseous HVOF system (GHVOF) is emphasized on reduction of the cost of coatings and increasing the in-situ removability to suit various working conditions. DZ9000E hand-held spraying gun is assembled with dual-valve handle, ON/OFF switches for powder feeding, and compressing and cooling valve, which can provide portable and simple operation mode for users. The whole system is economical, which enables the system to meet the requirement of spraying medium or low cost HVOF coatings for medium and small job shops. The deposited cermets coatings by the DZ9000E system have good performance with average micro hardness of over HVOF 2900 and the bond strength between coating and substrate of over 50MPa.
Characterization and Evaluation of Nanostructured Bond Coats from Noncryogenically Milled Feedstock
Authors: Kim G.E. , Addona T. , Richer P. , Jodoin B. , Al-Mathami A. , Brochu M. 
Published: September 2022

Abstract
Thermal barrier coatings (TBCs) with nanostructured bond coats have shown significant thermal cycling enhancements over their conventional microstructured counterparts; however, the high cost inherent to the cryomilling processing of the MCrAlY powder limits commercial application. Hence, this study characterizes and evaluates nanostructured bond coats derived from non-cryogenically milled MCrAlY powder with emphasis placed on reduced processing cost and scale-up capability. After extensive development of both a high-energy planetary mill and its operating parameters, fine-grained equiaxed NiCrAlY powder has been produced. XRD and SEM characterization of the milled powder will be presented. Microstructural analyses of the coatings sprayed via the HVOF and cold spray processes will also be carried out, in addition to some preliminary static oxidation test results of the conventional and milled NiCrAlY.