bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Aluminium Oxidation Induced by a Q-switched Nd:YAG Laser Treatment and Its Influence on the Adhesion Properties of a Plasma-Sprayed Alumina Coating
Authors: Barnier V. , Costil S. , Li H. , Coddet C. , Oltra R. 
Published: September 2022

Abstract
The aim of this work was to study the modifications induced by 10 ns single or cumulative pulses of a Q-switched Nd:YAG laser emitting in the near-infrared (λ = 1064 nm) on a pure aluminum surface with a laser energy density leading to a regime of interaction below the material ablation. The influence of these laser substrate pre-treatments on the mechanical behavior of an 83 µm thick alumina plasma sprayed coating was observed by evaluating the integrity of the coating/substrate interface with a "laser-ultrasonic method" thanks to a special set up using a probe laser interferometer. An increase in the alumina coating adhesion considering cumulative pulses for a laser energy density of 0.7 J/cm2 was observed above 100 laser pulses. The highest adhesion was obtained for a laser treatment considering 1000 shots. For a single pulse laser treatment, this increase was found applying an energy density of 1.8 J/cm2. These results were correlated with the observation of modifications on topography and morphology of the aluminum surface after laser irradiations using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that the improvement of the adhesion of the plasma-sprayed alumina coatings was correlated to changes of the aluminum oxide morphology.
Microstructures and Compositions of Photocatalytic Plasma-Sprayed Titania-Hydroxyapatite Coatings
Authors: Ye F.-X. , Ohmori A. , Tsumura T. , Nakata K. , Li C.-J. 
Published: September 2022

Abstract
Hydroxyapatite (HAp Ca10(PO4)6(OH)2) is very known to be a biomaterial and an absorbent for chromatography. In this study, HAp was agglomerated with anatase TiO2 to manufacture thermal spray powders to improve the absorption activity of TiO2 and then improve its photocatalytic activity. The microstructures and compositions of plasma sprayed TiO2, TiO2-10%HAp, TiO2-30%HAp and HAp coatings were investigated. Due to the low thermal conductivity of HAp compound, not all HAp particles fully melted even under the arc current of 800 A. Low temperature stable β-Ca3(PO4)2 was detected in the sprayed HAp coatings. The addition of HAp inhibited the phase transformation of anatase TiO2 to rutile. Under the arc current of 600 A, the anatase content in the TiO2, TiO2-10%HAp and TiO2-30%HAp coatings was 10.6%, 20% and 42%, respectively. Although slightly decomposition of HAp to α-Ca3(PO4)2 was found in the TiO2-30%HAp coatings, it did not decompose to CaO and P2O5 according to the XRD and EDAX analysis. With the increasing of the spraying distance from 70 mm to 110 mm, the anatase content in the TiO2-30%HAp coatings decreased from 34% to 17% under arc current of 700 A. The addition of the secondary gas of helium has no significant influence on the melting state of the TiO2-HAp feedstock powders.
Apatite Formation on Vacuum Plasma Sprayed Titanium Coating after Chemical Modification
Authors: Chen Y.K. , Ji H. , Zheng X.B. 
Published: September 2022

Abstract
Formation of bonelike apatite is an essential prerequisite for implants to make direct bond to living bone. The apatite formation can be assessed in vitro using a simulated body fluid (SBF) that has almost equal compositions of inorganic ions to human blood plasma. In this study, Ti coatings were prepared by vacuum plasma spraying, and then they were treated by NaOH aqueous solution, immersed in distilled water, heated at 600 °C in a furnace. Microstructure and bioactivity of the surface modified Ti coatings were examined by SEM observation and SBF test respectively. The results obtained revealed that a net-like structure comprising of many micropores was present on the surfaces of the treated Ti coatings. After immersed in SBF, apatite layer was formed on their surfaces, suggesting that the surface modification coatings have good bioactivity.
Bioactivity of Plasma Sprayed Calcium Silicate/ZrO2 Composite Coatings
Authors: Liu X. , Xie Y. , Ding C. 
Published: September 2022

Abstract
In this work, 30wt% calcium silicate, including wollastonite and dicalcium silicate, were mixed with 70wt% ZrO2, respectively. The composite powders were deposited onto Ti-6Al-4V substrates to prepare wollastonite/ZrO2 and dicalcium silicate/ZrO2 composite coatings using plasma spraying technology. The bioactivity of coatings was evaluated using simulated body fluid soaking test. After the composite coatings were soaked in simulated body fluid for a certain period, apatite was formed on the surface of the wollastonite/ZrO2 and dicalcium silicate/ZrO2 composite coatings. In addition, the ZrO2 in composite coatings may protect the calcium silicate in the coatings from dissolving in simulated body fluid.
Effect of Heat Treatment on Pore Architecture and Associated Property Changes in Plasma Sprayed TBCs
Authors: Paul S. , Golosnoy I.O. , Cipitria A. , Clyne T.W. , Xie L. , Dorfman M.R. 
Published: September 2022

Abstract
Plasma sprayed Thermal Barrier Coatings (TBCs) exhibit many interlamellar pores, voids and microcracks. These microstructural features are primarily responsible for the low global stiffnesses and the low thermal conductivities commonly exhibited by such coatings. The pore architecture thus has an important influence on such thermophysical properties. In the present work, the effect of heat treatment (at temperatures up to 1400°C, for times of up to 10 hours) on the pore architecture in detached YSZ top coats has been characterised by Mercury Intrusion Porosimetry (MIP) and gas-sorption techniques. While the overall porosity level remained relatively unaffected (at around 10-12%) after the heat treatments concerned, there were substantial changes in the pore size distribution and the (inter-connected) specific surface area. Fine pores (&lt;~50 nm) rapidly disappeared, while the specific surface area dropped dramatically, particularly at high treatment temperatures (~1400°C). These changes are thought to be associated with intra-splat microcrack healing, improved inter-splat bonding and increased contact area, leading to disappearance of much of the fine porosity. These microstructural changes are reflected in sharply increased stiffness and thermal conductivity. Measured thermal conductivity data are compared with predictions from a recently-developed analytical model, using the deduced inter-splat contact area results as input parameters. Good agreement is obtained, suggesting that the model captures the main geometrical effects and the pore size distribution measurements reflect the most significant microstructural changes.
Preliminary Study of Oxidation Behavior of Cold Sprayed Nanostructured NiCrAlY Bond Coatings
Authors: Zhang Q. , Li C.-J. , Li C.-X. , Yang G.-J. , Wang X.-R. , Wang H.-T. , Lui S.-C. 
Published: September 2022

Abstract
Nanostructured NiCrAlY coating was deposited by cold spray, using a milled powder for applications as a bond coat to thermal barrier coating. A shot-peening treatment was then applied to the as-sprayed coating to modify the coating surface morphology. The oxidation behavior of the coating with the shot-peened surface was investigated under isothermal oxidation at 900°C and 1,000°C for different times. The oxidation behavior of the coating was characterized through surface morphology and cross-sectional microstructure by scanning electron microscopy and X-ray diffraction analysis. It was found that a uniform oxide layer was formed on the surface of the shot-peened nanostructured NiCrAlY coating during oxidation at temperatures of 900°C and 1,000°C. The nanostructure of the initial coating possibly promoted rapid formation of α-Al2O3 oxide. It was clearly revealed that the surface morphology of the coating significantly impacted the morphology of the oxide. The surface geometry of the cold-sprayed MCrAlY coating must be modified to promote formation of a protective oxide film during oxidation, through application of a post-treatment process such as shot-peening.
Study of Microstructure, Vickers Microindentation and Microhardness Distribution of HVOF Sprayed Composite MoB/CoCr Coating
Authors: Lv H.P. , Wang J. , Zhai C.S. , Li F. , Sun B.D. 
Published: September 2022

Abstract
Thermal spray coatings of new MoB/CoCr cermets were developed. The mechanical behavior of HVOF-sprayed MoB/CoCr novel composite coatings was evaluated via Vickers microhardness. Microstructure of the coatings on 316L stainless steel substrates, as well as powders, were studied with optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD). X-ray microanalysis of the coatings was carried out using energy dispersive X-ray spectrometer (EDS) attached to the SEM. The distributions of microhardness values of the coatings were analyzed via Weibull statistic. Weibull analysis revealed a bimodal distribution of Vickers microhardness values. Such distribution was attributed to the presence of melted and unmelted phases in the resultant coating produced from the microstructured powder feedstock. The excellent mechanical properties of the coating are due to the MoB/CoCr powder, which results in the formation of complex ternary transition metal boride hard particles that exhibit exceptional mechanical properties.
On the Role of Spraying Process on Microstructural, Mechanical and Thermal Response of Alumina Coatings
Authors: Costil S. , Verdy C. , Bolot R. , Coddet C. 
Published: September 2022

Abstract
Thermal spraying is a widely used technology in a range of industrial applications to provide coatings improving the surface characteristics. According to the thermal and kinetic specificities of processes (APS, VPS, flame, electric arc), any kind of material can be sprayed. Among materials, ceramic coatings present several interesting aspects for wear resistance, corrosion protection as well as for thermal or electrical insulation; particularly alumina coatings which appear as the most commonly used. Many techniques can be used to spray such kind of materials. From all of them, atmospheric plasma spraying (APS) is a rather well-established process but some other processes can also be used with a lower economical impact as the flame technology. The aim of this study was to analyse the alumina coating properties according to the technology employed such as atmospheric plasma spraying or wire flame spraying using the Rokide and the Master Jet guns. After usual micrographic analyses by SEM, physical and mechanical properties were measured considering the thermal conductivity and the hardness.
Oxidation and Hot Corrosion Resistance of HVOF Wc-NiCrFeSiB Coating on Ni- and Fe-based Superalloys at 800 °C
Authors: Sidhu T.S. , Malik A. , Prakash S. , Agrawal R.D. 
Published: September 2022

Abstract
The present work evaluates the oxidation and hot corrosion resistance of high velocity oxy-fuel (HVOF) sprayed WC-NiCrFeSiB coating deposited on Ni-based superalloy (Superni 75) and Fe-based superalloy (Superfer 800H). The coated as well as uncoated specimens were exposed to air and molten salt (Na2SO4-25%NaCl) environment at 800 °C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. The corrosion products were characterized using the combined techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe micro analyser (EPMA). The WC-NiCrFeSiB coating provides necessary resistance against oxidation and hot corrosion to both the nickel and iron based superalloys in the given environmental conditions at 800 °C. The oxides of active elements of the coatings, formed in the surface scale as well as at the boundaries of nickel and tungsten rich splats, have contributed for the oxidation and hot corrosion resistance of WC-NiCrFeSiB coatings, as these oxides act as barriers for the diffusion/penetration of the corrosive species through the coatings.
Study on Corrosion Resistance Properties of Al-based Coating Prepared by Arc Spraying
Authors: Ren C.L. , Wei Q. , Fang J.Y. , Li Z.X. , Zhou X.J. 
Published: September 2022

Abstract
Al-based coating was prepared with Al-based cored wire by arc spraying. The properties of high-temperature oxidation resistance and corrosion resistance of Al-based coating were compared with those of Fe-Al coating and 45CT coating. The property of H2S corrosion resistance of Al-based coating was compared with that of A304 stainless steel and Fe-Al coating. The results suggest that the Al-based coating has better properties of high-temperature oxidation resistance and corrosion resistance than Fe-Al coating and 45CT coating. Al-based coating has better property of H2S corrosion resistance than A304 stainless steel and Fe-Al coating.
Corrosion Study of Cold Sprayed Aluminum Coatings onto Al 7075 Alloy
Authors: Irissou E. , Arsenault B. 
Published: September 2022

Abstract
Aluminum coatings were deposited onto Al7075 T651 structural alloy using both cold spraying and arc spraying. Arc spray coatings were produced using optimized parameters for two atomizing gases, namely air and nitrogen. Cold spray coatings were produced using a low pressure system with air and nitrogen as propelling gases. Six surface preparation procedures prior to deposition were evaluated. Interface quality of as-deposited coatings was investigated by means of fluorescent dye interface penetration technique, bond strength testing and backscattered electron microscopy. Environmentally assisted cracking tests were performed to study the corrosion protection capability of the resulting coatings for structural applications. Micrographs of samples taken before and after cyclic load testing in salt water immersion were compared. The results demonstrated that the Al coatings produced by both arc spray and cold spray provide to Al7075 alloy a cathodic protection against cracking and localized corrosion. However, to obtain such coating properties arc spray technique required advanced surface preparation prior to deposition. For cold spray, the surface preparation has minimal influence on the coating properties thus making this process more advantageous than arc spraying for this application.
The Oxy-Fuel Ionisation (OFI) Spray Processes
Authors: Barykin G. , Parco M. 
Published: September 2022

Abstract
Owing to gas velocities in the super-sonic regimen in combination with moderate flame temperatures, the HVOF processes are preferred for the deposition of wear and/or corrosion resistant carbides as well as Hastelloy, Triaballoy and Inconel alloys. The resulting coatings have usually very high bond strengths, fine as-sprayed surface finishes and low oxide levels. However, the generation of a supersonic flow of combustion products supposes the implementation of relatively high gas flow rates and high energetic gas mixtures, which are intrinsically associated with high production costs, limiting the application of this technology in some industrial fields. This work summarises the first results in the development of a prototype aimed to show the potential of a new thermal spray technology named Oxy-Fuel Ionisation spraying for the development of high quality carbide base coatings. The OFI process is a supersonic combustion process as well, enhanced by the addition of ionised gas specimens. The arising combustion process is characterised by its stability within a broader range of the “fuel/oxidant” correlation in comparison to conventional HVOF systems, because of the presence of ionised gas specimens which are acting as a catalyst. It has been proved that this developed prototype allows the thermal spray deposition of carbide based materials with relatively low oxygen flow rates. For comparison two different coating materials were investigated, WC-17Co and Cr3C2-NiCr. The process parameters were optimised in terms of the micro hardness, the porosity and the decarburization of the resulting coatings.
Development of Nanostructured Thermal Barrier Coatings
Authors: Jiang X.L. , Liu C.B. , Lin F. 
Published: September 2022

Abstract
In this paper, nanostructured 5-8wt.% yttria stabilized zirconia (5-8YSZ) thermal barrier coating (TBC) deposited by air plasma spraying (APS) of powder and new TBC with novel structure deposited by solution precursor plasma spray (SPPS) are compared. Plasma spray conditions, coating forming mechanisms, microstructures, phase compositions, thermal conductivities, and thermal cycling lives of the APS nanostructured TBC and the SPPS nanostructured TBC are discussed. The SPPS process is different from either physical/chemical vapor deposition process or conventional plasma spray deposition in the aspects of substrate temperature, coating forming mechanism, growth rate, and coating structure.
Rapid and Continuous Deposition of Porous Nanocrystalline SnO2 Coating with Interpenetrating Pores for Gas Sensor Applications
Authors: Chien K. , Coyle T. 
Published: September 2022

Abstract
In this paper we proposed a rapid and continuous process for the production of nanoporous coatings for functional applications. Experiments following two statistical designs were implemented to screen and investigate the spraying parameters’ effects on coating crystallinity and porosity to gain a better understanding. The spraying stand-off distance, solution flow rate and arc current were identified as having significant effects on coating porosity and crystallinity. The investigation yielded a microstructure comprised of interpenetrating pores and layered structures with embedded nanopores. A deposition mechanism was postulated to explain this peculiar microstructure. Gas sensors constructed from the coatings had ethanol sensitivities at room temperature comparable to those reported in the literature for conventional thick-film coatings and a maximum sensitivity near 200°C.
Triplex Pro 200 – Potential and Advanced Applications
Authors: Bobzin K. , Ernst F. , Zwick J. , Richardt K. , Sporer D. , Molz R.J. 
Published: September 2022

Abstract
Process optimization and innovative material applications gain more and more interest under the aspect of continuously increasing functional and structural demands on thermal sprayed coatings. With the cascaded triple arc plasma gun generation, the atmospheric plasma spraying process was advanced by delivering enhanced plasma stability and, associated with this, higher deposition efficiency. The TriplexPro 200 is the latest version of a three cathode plasma spraying system on the market and offers distinctly higher particle velocities, due to its advanced nozzle design. As a result of the higher particle velocities, lower particle oxidation and higher coating density can be realized. In order to increase the corrosion protection of metallic coatings and the thermal properties of TBCs, the aim of the work performed is a parametric study to deposit advanced coating systems for high temperature applications.
Fragmentation and Splashing of Plasma-Sprayed Nickel on Oxidized Metals
Authors: McDonald A. , Chandra S. , Lamontagne M. , Moreau C. 
Published: September 2022

Abstract
Plasma-sprayed, molten nickel particles (60 µm diameter) were photographed during impact on oxidized 304L stainless steel surfaces that were maintained at room temperature or at 350oC. The steel samples were oxidized at different temperatures. Droplets approaching the surface were sensed using a photo detector and after a known delay, a fast charge-coupled device (CCD) camera was triggered to capture time-integrated images of the spreading splat from the substrate front surface. A two-color pyrometer was used to collect the thermal radiation from the particles to follow the evolution of their temperature after impact. Molten nickel particles impacting on oxidized steel at room temperature fragmented significantly, while heating the surfaces produced splats with disk-like morphologies. Impact on steel that was highly oxidized induced the formation of finger-like splash projections at the splat periphery. The splat cooling rate and thermal contact resistance between the splat and non-heated oxidized steel varied significantly as the degree of oxidation increased; heating the oxidized steel greatly reduced the variations. It was suggested that the large variations in splat cooling rates and thermal contact resistances on the non-heated oxidized steel was due primarily to the presence of adsorbates on the steel surface.
Synthesis of Lanthanum Silicates with Apatite-type Structure by Atmospheric Plasma Spraying
Authors: Gao W. , Zhang C. , Lapostolle F. , Liao H. , Coddet C. , Ji V. 
Published: September 2022

Abstract
The emergence of lanthanum silicate as an electrolyte is required to accelerate the development of synthesis techniques for intermediate temperature solid oxide fuel cells (ITSOFCs). Apatite-type oxide powders of La10(SiO4)6O3 have been elaborated through atmospheric plasma spraying (APS) using micro-scale mixtures of La2O3 and SiO2 powders. Granulometer and scanning electron microscopy analyses have indicated the result of high temperature reaction and rapid solidification in the evolution of multi-scale microstructure.
Comparison of the Microstructures and Tribological Behavior of Blended and Nanostructured Composite Coatings by APS
Authors: Cho J.H. , Xiong Y.M. , Kumar S. , Ji Y.G. , Lee C. , Hwang S.Y. 
Published: September 2022

Abstract
A group of blended and spray dried solid lubricants with the same nominal composition were deposited by atmospheric plasma spraying (APS). The wear resistance of two coatings formed at room temperature and 350°C was evaluated using a rig test to simulate actual application conditions. The results showed that the blended powder coating showed inferior mechanical and tribological properties due to its non-uniform microstructure, which were induced by the differences in the physical and thermophysical properties of each constituent phase. However, the nanostructured spray-dried feedstock coating showed a better wear resistance due to its lower porosity, higher hardness and higher bond strength. In addition, the friction coefficient decreased with an increase of the Ag fraction and the uniformity of the Ag solid lubricant in the coating.
Optimization of Sensor Optics for Industrial Thermal Spray Sensors
Authors: Blain J. , Pouliot L. , Nadeau F. , Lamontagne M. , Moreau C. 
Published: September 2022

Abstract
For a decade now, industrial sensors have been commercially available to both academia and industry. In general, these sensors measure individual and/or bulk properties of the powders being sprayed. Experience has shown that normally, researchers will tend to favor sensors with high spatial resolution like the DPV 2000, because of the fundamental information they give about the plume structure. Such information is vital for proper gun design and spray parameter optimization. However, for process monitoring applications typically performed with a sensor like the AccuraSpray, it is often more convenient to measure global properties over a wider volume inside the plume. In this case, there is always a tradeoff to be made between spatial resolution and fundamental process understanding. This paper illustrates this point by comparing two optical configurations, one with high spatial resolution and another one with medium resolution. This latter configuration makes use of a cylindrical lens to expand the sensor field of view in a direction perpendicular to the spray direction. Results clearly show that with minor optical modifications such sensors can be tailored to precise industrial requirements.