bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the Powder Morphology and Alumina Content in Cold-Sprayed Ni-Al2O3 Coatings
Authors: Sevillano F. , Poza P. , Múnez C. J. , Vezzù S. , Rech S. , Trentin A. 
Published: November 2022

Abstract
Coldspray is becoming a consolidated technology in deposition of several metallic coatings such as aluminium, titanium, nickel, copper and their alloys. However, increasing attention is paid to the capabilities of coldspray to deposit composite Cer-Met coatings starting from powders blends. High ceramic content coatings are difficult to get by Cold-Spray technique due to the low ductility of the ceramic phase, but as for metal coatings the low deposition temperature reduce the residual stresses, coating porosity and oxidation. Furthermore, using powder blends, obtained by quickly mixing the pure components, leads to a great versatility on materials usable for deposition. In present work, the influence of alumina content on coldspray deposition of Ni-Al2O3 coatings was studied. Five different powder blends were prepared, the ceramic content was set as 10, 25, 50, 75 and 90 weight percent of alumina. Ni-pure coatings have been prepared and compared with composites coatings. Characterization techniques were employed in order to determine the coating morphology and microstructure , with special attention to determine the real alumina content in the coating with respect to initial powder feedstock. The final coating porosity and the matrix hardness were also evaluated. Finally, the performance of the coatings in terms of oxidation resistance was determined and discussed.
Effects of Particle Strength of Feedstock Powders on Properties of Warm-Sprayed WC-Co Coatings
Authors: Chivavibul P. , Watanabe M. , Kuroda S. , Kawakita J. , Komatsu M. , Sato K. , Kitamura J. 
Published: November 2022

Abstract
Warm Spray (WS) process, which can control the temperature of a combustion gas jet used to propel powder, has been successfully applied to deposit WC-Co coatings. Detrimental reactions resulting from dissolution of WC into Co binder and decarburization were suppressed effectively by keeping the WC-Co particles’ temperature below the m.p. of the binder phase. In this study, three nano-structured WC-12Co powders with different particle strength were prepared by changing the sintering conditions of spray-dried powder and were deposited by WS. The deposition efficiency and porosity of the coatings decreased with increasing the particle strength. The coating deposited from the powder with very low particle strength showed significant phase changes, while those deposited from the higher particle strengths showed almost no change. Particle Image Velocimetry revealed significant disintegration of the weakest powder, which explains the changes observed. The hardness and wear properties of the former coating, therefore, were inferior to the other two.
Microplasma Wire Spraying of Biomedical Ti-Coatings
Authors: Borisov Yu. , Kyslytsya O. , Voinarovych S. , Kuzmyc-Ianchuk Ie. , Pidgaetskyi V. 
Published: November 2022

Abstract
Biomedical Ti-coatings were deposited on Ti-substrates by the microplasma wire spraying method. The influence of different factors of the wire spraying process on sizes of the particles produced as a result of atomisation of the wire melt by the microplasma jet, as well as the deposition efficiency were determined by using multifactorial experimental design. Linear regression models were developed, showing the effect of the most significant process parameters (current, plasma gas flow rate, wire feed speed) on formation of a jet of the spraying Ti-particles, structure and properties of the Ti-coatings. Establishing the possibility of controlling macroporosity of the Ti-coatings in microplasma wire spraying and correspondence of the Ti-coatings bond strength in tensile and shear tests to the ISO 13779-2 and ASTM C633 requirements, as well as data of the Ti-coatings “in-vivo” tests proved the efficiency of using them for manufacture of various-purpose endoprostheses (hip joint, dental, etc.).
Development of Optical Monitoring for Thermal Spray Processing
Authors: Chivel Yu. , Smurov I. 
Published: November 2022

Abstract
A new approach has been developed for monitoring thermal spray processing that involves visualization of the movement of particles using a high speed video camera and wide-band intensive illumination to measure particle temperature, velocity, size, and distribution. Synchronously with the capture of the particle parameters, the surface temperature of the coating is measured with a two-channel pyrometer that has high spatial and a temporal resolution. This paper presents the results of investigations of cold spraying and D-gun spraying using these techniques.
Investigation and Comparison of Particle Parameters Determined with SprayWatch and LDA (Laser Doppler Anemometry) During the Cold Gas Spraying Process
Authors: Tewes J. , Hertter M. , Voggenreiter H. , Biermordt T. , Heinrich M. , Zimmermann S. , Landes K. , Schein J. 
Published: November 2022

Abstract
Properties and performance of coatings deposited by the Cold Gas Spraying process are affected by particle properties, which can be changed by using various spraying parameters. Different diagnostic systems can be applied to investigate these parameters. By means of the commercial SprayWatch system, particle properties (velocity, temperature, size, number density) can be measured and evaluated. In comparison the Laser Doppler Anemometry (LDA) system determines velocity and number density. Using both systems the velocity has been measured for a range of parameters, including different materials, different gas properties and nozzles thus offering the possibility to compare the two different diagnostic systems. In the present paper only the results of different gas properties will be shown.
Intelligent Gun Technology: Reducing Costs with EvoLink in R&D and Operations
Authors: Koller M. , Kilchenmann A. , Barth A. 
Published: November 2022

Abstract
A new technology has been introduced to measure process variables as well as to store gun-relevant data directly inside a thermal spray gun. This paper describes how this technology helps to reduce cost on the areas of process quality, maintenance and coating development. Test series have been carried out proofing reduced failure costs by detecting erroneous spray system configuration and functionality. Another section describes a cost decrease of maintenance prevention by intelligently using gun data. Additional test series show a cost reduction in parameter development in case of parameter transport to different thermal spray systems.
Nanostructured Metal Matrix Composite Coating Production by Pulsed Gas Dynamic Spraying
Authors: Yandouzi M. , Brochu M. , Jodoin B. 
Published: November 2022

Abstract
The objective of this work is to demonstrate the ability of the Pulsed Gas Dynamic Spraying process (also known as Shockwave Induced Spraying) to produce nanostructured metal matrix composite. Nanocrystalline and microcrystalline (conventional) Al5356+20%B4C composite feedstock powders were used. The influence of the coating process as well as the nature of the feedstock material on the microstructure and mechanical properties of the coatings were studied. The new spraying process provides an opportunity to produce hard and dense coatings with good cohesion between deformed particles and good adhesion to the substrate. No phase degradation, low compressive residual stresses and high dry sliding wear resistance were observed which seem to be an advantage compared to the traditional thermal spray coatings.
Modeling a Formation of Fe-Cr-Al Coating Produced By Arc Spraying
Authors: Korobov Yu. , Filippov M. , Nevezhin S. , Shallimov M. 
Published: November 2022

Abstract
Simulation of oxygen intake into Fe-Cr-Al coating at arc spraying was done. Based on the study of structure and properties of these coatings, the reliability of the model was evaluated.
An Efficient Numerical Method for Calculating the Shape of Structures Produced by Thermal Spraying
Authors: Ilin A. , Logvinov R. , Prihodovsky A. , Ploshikhin V. , Jonke D. 
Published: November 2022

Abstract
An advanced method for the efficient numerical prediction of the shape of the structure produced by thermal spray is presented. This method is based on the combination of a local non-linear thermo-mechanical FEM calculation of the inherent strain distribution after the process of thermal spraying in a representative sample and a global linear FEM calculation of the shape of the whole structure. One of the advantages of this method is the significant reduction of the computation time compared to a traditional transient FEM simulation. An application example shows the results of shape prediction of a large and complex structure generated by thermal spraying. The application of this method to the prediction of the shape of large structures opens the way for the optimization of the thermal spray technology towards the near net shape production process.
Understanding the Adhesion Mechanism of Cold Sprayed TiO2 Coatings
Authors: Tjitra Salim N. , Yamada M. , Isago H. , Shima K. , Nakano H. , Fukumoto M. 
Published: November 2022

Abstract
We have shown the fabrication of ceramics titanium dioxide (TiO2) coating via cold spray process. Cold spraying of any hard ceramics coating is considered to be difficult, including TiO2. However, we could obtain a coating with thickness greater than 100 µm. The adhesion mechanism of this cold sprayed TiO2 coating needs to be clarified. The effects of process gas parameters and substrate materials on coating's adhesion strength were studied. It was found that adhesion strength did not vary significantly with the change of process gas parameters, indicating that mechanical embedment is not the sole factor of coating¡¦s adhesion. The study of changing substrate materials reveals the degradation of adhesion strength due to surface oxide layer and that TiO2 shows better adhesion on bare metal surface. Hence, by altering the surface chemistry, the adhesion of TiO2 is varied, indicating the possibility of physical or chemical bonding between cold sprayed TiO2 and substrate.
Testing of the Electric Conductivity of Non-Ferrous Metallic Coatings
Authors: Trenkle F. , Vollmar H.-P. , Hartmann S. 
Published: November 2022

Abstract
For the development and quality control of highly electrically conductive coatings, a device is required by which the electric conductivity can be measured. For this purpose a handheld device for measuring the electric conductivity of nonferrous metals in a nondestructive manner was tested. The measurement principle is based on an eddy current sensor which allows determining the electric conductivity within seconds. The method fulfills the demands for using it in the environment of a job shop for thermal spraying. Coatings applied with different thermal spraying methods like cold gas, HVOF, electric arc or flame spraying have been examined. Thus, it will be presented a comparison of the electric conductivity dependent on different spraying methods. Additionally, important edge conditions for spraying and measuring the conductivity of highly electrically conductive coatings like the influence of the oxygen content of the powder, the minimal coating thickness measurable with the device and the influence of the surface roughness onto the measurement were analyzed.
Microtomographic Analysis of Splat Formation and Layer Build-Up of a Thermally Sprayed Coating
Authors: Tillmann W. , Nellesen J. , Abdulgader M. 
Published: November 2022

Abstract
Thermal spraying is a material processing technique, which is based on the combination of thermal and kinetic energy. The used feedstock is melted in a hot flame and the melt is atomized and accelerated by means of atomization or process gases. The formed particles are rapidly solidified and consolidate to form splats as they hit a pre-treated substrate. The splats pile one-on-top-of-other forming lamellas and creating the final coating. In the work presented here a combination of cored wire (WC as filling powder) and massive wire (copper) were simultaneously sprayed using the twin wire arc spraying (TWAS) process. 3D micro tomography was used in order to gain knowledge about splat formation and layer build-up. Due to the high attenuation coefficient of tungsten in comparison with copper and carbon tungsten-rich particles and splats can easily be spotted in the tomogram of the coating layer. It turns out that besides irregular formed flat splats also ball-shaped particles exist in the coating layer which suggests that the spherical particles impacted on the substrate in an un-molten state. By 3D data processing tungsten-rich particles were visualized to analyze their spatial distributions as well as their geometric parameters were quantified. This work aims at contributing to the understanding of spraying processes.
Oxidation Behavior of Bond Coats with and Without Y Addition
Authors: Izumi T. , Arikawa H. , Kojima Y. , Okada M. , Hisamatsu T. 
Published: November 2022

Abstract
In this study, the effects of bond coat compositions with and without 0.5 mass.% Y on oxidation behaviour were investigated. Oxidation behaviour was accessed in terms of The TGO structure and growth kinetics. After isothermal oxidation tests, the TGO formed on Y-free CoNiCrAl coatings was composed mainly of alumina without the presence of Y-rich oxide and showed lower growth kinetics than that formed on conventional CoNiCrAlY coating. This result indicates that potential improvements to the bond coat oxidation behaviour can be achieved using Y-free bond coat compositions.
Improving Atmospheric Plasma Spraying of Zirconate Thermal Barrier Coatings based on Particle Diagnostics
Authors: Mauer G. , Sebold D. , Vaßen R. , Stöver D. 
Published: November 2022

Abstract
Lanthanum zirconate (La2Zr2O7) was proposed as a promising material for thermal barrier coatings. At atmospheric plasma spraying (APS) of La2Zr2O7 a considerable amount of La2O3 can evaporate in the plasma flame, resulting in a non-stoichiometric coating. As indicated in the phase diagram of the La2O3-ZrO2 system, in the composition range of pyrochlore structure, the stoichiometric La2Zr2O7 has the highest melting point and other compositions are eutectic. APS experiments were performed with a TriplexPro-200 plasma torch at different power levels to achieve different degrees of evaporation and thus stoichiometry. For comparison, some investigations on Gd2Zr2O7 were included which is less prone to evaporation and formation of non-stoichiometry. Particle temperature distributions were measured by the DPV-2000 diagnostic system. In these distributions, characteristic peaks were detected at specific torch input powers indicating evaporation and solidification processes. Based on this, process parameters can be defined to provide stoichiometric coatings intended to show good thermal cycling performance.
Characterisation of HVOF-Sprayed Fe-Based Alloy Coatings
Authors: Bolelli G. , Bonferroni B. , Lusvarghi L. , Milanti A. , Niemi K. , Laurila J. , Vuoristo P. 
Published: November 2022

Abstract
The dry sliding wear behaviour of two HVOF-sprayed Fe-Cr-Ni-Si-B-C (Colferoloy) alloy coatings was studied by ball-on-disk tests performed at room temperature (against alumina and 100Cr6 steel balls), at 400 °C and at 700 °C (against alumina balls only). HVOF-sprayed Ni-Cr-Fe-B-Si-C and Cr3C2-NiCr layers were also tested for comparison. Under all test conditions, the wear rate of the Colferoloy coatings is lower than that of the Ni-Cr-Fe-B-Si-C coating but larger than that of the Cr3C2-NiCr cermet. Specifically, at room temperature, the Colferoloy coatings exhibit a combination of mild abrasion, delamination and tribo-oxidative wear against alumina, whereas, against steel, they undergo very limited delamination with negligible wear loss. By contrast, the Ni-Cr-Fe-B-Si-C coating suffers larger wear against steel and undergoes more severe abrasive grooving against alumina. Although the Colferoloy and Ni- Cr-Fe-B-Si-C coatings possess similar microstructure and micro-hardness, their scratch behaviours, which depend on cracking resistance and plastic deformability, differ, thus explaining the micromechanical reason for the different wear mechanisms. At 400°C and 700°C, all of the metal alloy coatings are softened and suffer more severe abrasive grooving; by contrast, the behaviour of the Cr3C2-NiCr layer at 700 °C is controlled by the formation and delamination of an oxidised layer.
Influence of Computational Grid Spacing on Gas/Particle Flow of Cold Spray
Authors: Katanoda H. 
Published: November 2022

Abstract
The grid-spacing dependency of the numerical solutions of the supersonic gas/particle impinging flow of the cold spray is investigated. The control parameters of the grid spacing in the nozzle are the radial grid spacing normal to the nozzle wall, the axial grid spacing at the nozzle exit, and the radial number of grids in the nozzle. The working gas is nitrogen with a pressure and a temperature of 2MPa and 600K at the stagnant chamber. The solid particle to be accelerated by the supersonic gas flow is spherical copper 5µm in diameter. The numerical results reveal that the computational result with coarsest grid poorly captures the supersonic gas flow in the nozzle. However, the impinging velocity of the particle onto the substrate differs less than 3.5% between those results obtained from the finest and coarsest grids.
Helium-Free Parameter Development for TriplexPro-210 Plasma Gun
Authors: Chen D. , Colmenares-Angulo J. , Molz R. , Dambra C. , Hawley D. 
Published: November 2022

Abstract
This paper focuses on the use of hydrogen and nitrogen as secondary gases for atmospheric plasma spray using the TriplexPro-210 gun platform. The paper includes process mapping of particle state in addition to measurements of actual stress states within the coating during coating application. The feedstock powders used for this investigation include yttria stabilized zirconia, chromium oxide, nickel chromium aluminum and nickel aluminum. In addition, the paper discusses differences in application costs.
Deposition of La-Sr-Fe-Co Perovskite Coatings with Different Microstructures by Low Pressure Plasma Spraying
Authors: Zotov N. , Hospach A. , Mauer G. , Sebold D. , Vaßen R. 
Published: November 2022

Abstract
Preparation of La1-xSrxFe1-yCoyO3-δ (LSFC) coatings by plasma spraying at low pressure (200 Pa) using different plasma spray parameters is reported and discussed. Deposition with Ar-He plasma leads always to formation of coatings containing a mixture of LSFC perovskite, SrLaFeO4, FeCo and metal oxides. Coatings deposited at higher oxygen partial pressures by addition of oxygen into the vacuum chamber contain more than 85% perovskite and only few percent Fe3O4 and/or CoO. The microstructures of the investigated LSFC coatings depend sensitively on the oxygen partial pressure, the substrate temperature and the deposition rate.
The Characteristic of Plasma Torch Designed for the Very Low-Pressure Plasma Spraying
Authors: Gao Y. , Yang D.-M. , Tian B.-H. 
Published: November 2022

Abstract
In contrast with the atmosphere plasma spraying (APS), the very low pressure plasma spraying (VLPPS) shows lower ability for heating spray materials at the plasma free region exit of nozzle. Most very low pressure plasma spraying at the present usually use a high power plasma gun which operated at great arc currents up to 2500A to meet lower ability for heating materials, thus result in a series of problems not only for the plasma torch but also for associated facility. According to the plasma spray characteristic in the low pressure environment we designed a plasma torch with separating anode and nozzle, and the powder injected to the plasma jets is from inside nozzle intake. In this study, the pressures in the plasma gases intake, nozzle intake and out of the plasma torch were measured respectively. For the practice, SUS 316 stainless steel coatings were prepared at plasma currents of 500-600A and arc voltage of 50V and the chamber pressure of 1000 Pa, the results indicated that the coatings with the equiaxed microstructure could deposited in the appropriate conditions.
Reconstitution of Yttria-Stabilised Zirconia Nanopowders to Obtain Coatings by Atmospheric Plasma Spraying
Authors: Sánchez E. , Felíu C. , Carpio P. , Bannier E. , Moreno R. , Alcázar M. C. , Salvador M. D. , Benavente R. , Bonache V. 
Published: November 2022

Abstract
Yttria-stabilised zirconia (YSZ) coatings were deposited on austenitic stainless steel coupons from nanostructured powders using atmospheric plasma spraying (APS). Two suspensions of YSZ nanoparticles were used as starting material: a diluted commercial suspension and a highly concentrated in-house prepared suspension (obtained by adding an YSZ submicronic powder to the diluted suspension). Both suspensions were reconstituted into sprayable micrometric granules. The reconstitution process was performed by spray drying, followed by a thermal treatment in order to reduce porosity and enhance agglomerate sinterability. The reconstituted powders were characterised by XRD, SEM, granule and pore sizing techniques, and a flowability evaluation. The effect of suspension characteristics on granule morphology and porosity was examined. The reconstituted powders were successfully deposited, yielding well-bonded coatings. The coating microstructure was characterised by XRD and SEM. Mechanical properties and erosion resistance were also determined. Coating microstructure consisted of semi-molten feedstock agglomerates surrounded by fully molten areas that acted as binders. The influence of feed powder characteristics on coating microstructure and properties was also studied.
Comparison of Isolated Indentation and Grid Indentation Methods for HVOF Sprayed Cermets
Authors: Nohava J. , Houdková Š. , Plzeň CZ , Haušild P. , Enžl R. 
Published: November 2022

Abstract
This paper compares the results of two approaches of instrumented indentation for characterization of mechanical properties of HVOF coatings. Three types of industrially used HVOF sprayed coatings (Cr3C2-NiCr, WC-Co, (Ti, Mo)(C,N)-NiCo) were selected. The indentation methods applied were: isolated nanoindentation in metallic matrix and carbides with 2 mN peak load and grid indentation with 2 mN peak loads, comprising 400 indentations. The results of the isolated indentation revealed hardness and elastic modulus of the individual phases with surprisingly low standard deviation and in good agreement with the corresponding bulk equivalent. The grid indentation method, based on statistical evaluation of a large number of indentations, was influenced by the carbide-matrix interface, which gave rise to a strong third peak apart from the two peaks corresponding to the hard carbides and softer metallic matrix. This makes the statistical analysis much more complex than using simple bimodal Gaussian fit for separation of matrix and carbide properties. Nevertheless, the results of both grid indentation and isolated nanoindentation compared with microindentation values obtained at higher loads gave important information about the cohesion of the coatings.