bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy Efficient Production of Thermally Sprayed Coatings Through the Use of Modified Twin Wire Arc Spraying Processes – Final Results of a Bavarian Research Foundation Funded Project
Authors: Atzberger A. , Hartz-Behrend K. , Schein J. , Steiner E. , Blau L. , Mayr W. , Szulc M. , Zierhut J. , Krömmer W. , Lang F. , Aumiller M. , Abler E. 
Published: November 2022

Abstract
The main goal of the project was to investigate the influence of different gas properties, in combination with different spraying parameters, on the wire arc spraying process. For this purpose, investigations with several gas compositions (pure nitrogen as well as nitrogen combined with hydrogen or ethene – compared to compressed air) have been carried out for different spraying materials which are currently being used in today’s industries, such as copper, carbon (St0.8) and stainless steels (316L). The preheating of the process gas as well as the variation of the gas pressure up to 1,400 kPa (14 bar) were also subject to research. The resulting coating properties have been analyzed in terms of oxide content, porosity and hardness as well as deposition efficiency and adhesive tensile strength. Additionally, in order to enhance the process stability, a system to detect the cause of cold shuts has been developed.
The Effect of Molybdenum Substrate Oxidation on Splat Formation
Authors: Wang J. , Li C. 
Published: November 2022

Abstract
Disk splats are usually observed when the deposition temperature exceeds the transition temperature, whereas thick oxide layer will reduce the adhesion resulting from high deposition temperature. In present study, single molybdenum splats were sprayed onto polished molybdenum substrates with different preheating processes to clarify the effect of surface oxidation on the splat formation. Three preheating processes included heating the substrate to 350 °C, 550 °C, and cooling the substrate from 550 °C to 350 °C, which were performed in argon atmosphere. The chemistry and compositions of substrate surface was examined by XPS. The cross sections of splats were prepared by focus-ion-beam (FIB), and then characterized by SEM. Nearly disc-shaped splat with small fingers in the periphery was observed on the substrate preheated to 350 °C. Perfect disc-shape splat was deposited at 550 °C. Flower-shaped splat exhibited a central core and discrete periphery detached by some voids on the substrate preheated to 350 °C (cooling down from 550 °C). The results of peeling off splats by carbon tape and morphology of FIB sampled cross-sections indicated that no effective bonding formed in the splat-substrate interface for the substrate ever heated to 550 °C, due to the increasing content of MoO3 on preheated molybdenum surface.
Characterization of Aluminum Based Coatings Deposited by Very Low Pressure Plasma Spray
Authors: Fan X. , Planche M.-P. , Darut G. , Kang N. , Montavon G. 
Published: November 2022

Abstract
The objective of this research is to investigate the changes of the microstructure and mechanical property of aluminum based coatings manufactured by VLPPS along the radial directions of the plasma plume. Aluminum powders were sprayed with a F4-VB low-power plasma gun under a working pressure of 150 Pa. Coatings deposition is studied at different distances from the plasma plume impact. Front of the plasma plume, in-situ reactions between aluminum and substrate elements (such as Fe, Cr, Ni) present in the base metal take places. It mainly forms aluminum based intermetallic Al3Fe coating according to the XRD. Based on the SEM observation, the packed columnar microstructure mixed with nanometer particles is formed with a majority of pure vapor condensation due to evaporated particles from the plasma jet and/or aluminum coating already made. For different distances relative to the center of plasma plume (i.e. from 10 mm to 110 mm along the radial directions), the deposited coatings exhibit a lamellar binary structure which was formed by the mixed deposition of vapor and molten droplets. The coatings morphologies vary from nearly dense to loose and highly porous. Finally, the hardness of typical coating is investigated. The Al based intermetallic AlxFey coating, on the center of the plasma plume, reached 448HV0.025, which is much higher than those obtained at other positions.
Open FOAM Modelling of Particle Heating and Acceleration in Cold Spraying
Authors: Leitz K.-H. , O’Sullivan M. , Plankensteiner A. , Kestler H. , Sigl L. S. 
Published: November 2022

Abstract
In cold spraying a powder material is accelerated and heated in the gas flow of a supersonic nozzle to velocities and temperatures that are sufficient to obtain cohesion of the particles to a substrate due to plastic deformation. The deposition efficiency of the powder particles is significantly determined by their velocity and temperature. The particle velocity correlates with the kinetic energy of the particles and thereby with the amount of energy that is converted to plastic deformation and thermal heating. The initial particle temperature significantly influences the mechanical properties of the particle. Velocity and temperature of the particles have nonlinear dependence on the pressure and temperature of the gas at the nozzle entrance. Whereas the particle velocity can easily be measured during the process, the particle temperature is not directly accessible by experimental techniques. Generally information about the particle temperature can be obtained based on theoretical models. In this contribution a simulation model based on the reactingParcelFoam solver of OpenFOAM is presented and applied for an analysis of the cold spray process. The model combines a compressible description of the gas flow in the nozzle with a Lagrangian particle tracking. The predictions of the simulation model are verified based on an analytical description of the gas flow, the particle acceleration and heating in the nozzle. Based on experimental data the drag model according to Plessis and Masliyah is identified to be best suited for OpenFOAM modelling particle heating and acceleration in cold spraying.
The High Temperature Wear and Oxidation Behavior of CrC-Based HVOF Coatings
Authors: Houdková Š. , Česánek Z. , Smazalová E. 
Published: November 2022

Abstract
The 3 commercially available CrC-based powders with different kind of matrix (Cr3C2-25%NiCr; Cr3C2- 25%CoNiCrAlY and Cr3C2-50%NiCrMoNb) were deposited by HVOF JP-5000 spraying gun, evaluated and compared. The sliding wear resistance, measured at room and elevated (T=600°C) temperature according to ASTM G-133, the influence of heat treatment on the microstructure and properties, as well as the oxidation resistance in hot steam environment (p=24 MPa; T=610°C) were evaluated with respect to their potential application in steam power industry. The surface oxidation and microstructure changes were evaluated by SEM and XRD. The NiCr matrix proved to provide high oxidation and sliding wear resistance of the coating regardless volume content. On the contrary, the Cr3C2-25%CoNiCrAlY coating was subjected to massive oxidation of carbide particles. The low cohesive strength and high porosity of Cr3C2-25%CoNiCrAlY was identified responsible for its poor oxidation resistance in hot steam environment. The sliding wear resistance was found comparable at room temperature, regardless the matrix composition and content, while at elevated temperatures, the higher volume content of matrix led to higher wear of coating material.
Effect of Carbide Dissolution in the Metal Matrix of HVOF and HVAF Sprayed Cr3C2-NiCrMoNb Coatings on the Initial Stage of Chlorine High Temperature Corrosion
Authors: Fantozzi D. , Matikainen V. , Uusitalo M. , Koivuluoto H. , Vuoristo P. 
Published: November 2022

Abstract
Highly corrosion and wear resistant thermally sprayed chromium carbide (Cr3C2) based cermets coatings are nowadays a potential highly durable solution to allow traditional fluidised bed combustors (FBC) to be operated with ecological waste and biomass fuels. However, the heat input of thermal spraying processes causes carbide dissolution in the metal binder. This alters the coating structure and forms carbon saturated amorphous and nanocrystalline metastable areas, which can affect the behaviour of the materials under the corrosive chlorides containing environment of the flue gases. This study analyses the effect of carbide dissolution in the metal matrix of MMC coatings and its effect on the onset of chlorine induced high temperature corrosion. Four Cr3C2-NiCrMoNb coatings were thermally sprayed with high-velocity air-fuel (HVAF) and high-velocity oxygen-fuel (HVOF) spray processes in order to obtain microstructures with increasing amount of carbide dissolution in the metal matrix. The specimens were heat treated in an inert argon atmosphere at 700°C for 5 hours to induce secondary carbide precipitation. As-sprayed and heat-treated self-standing coatings were covered with KCl and their corrosion resistance was investigated with thermogravimetric analysis (TGA) at 550°C for 4 hours. High carbon dissolution in the metal matrix appeared to be a detrimental factor in the initial stage of corrosion. The microstructural changes induced by the heat treatment hindered the corrosion onset in the coatings. Moreover, an optimal amount of oxides and melting degree seemed beneficial.
Comparative Study of the Corrosion and Cavitation Resistance of HVOF and HVAF FeCrMnSiNi and FeCrMnSiB Coatings
Authors: Silveira L. L. , Pukasiewicz A. G. M. , Björklund S. , Nylén P. , Zara A. J. 
Published: November 2022

Abstract
Cavitation and corrosion on hydrodynamic components and systems reduces the operational efficiency. The use of wear resistant coatings have been studied as a solution to the problem of corrosion and cavitation in the industrial environment. Thermal spray processes are recognized as excellent technique to deposit coatings. The high velocity oxy-fuel process (HVOF) can produce high density and bond strength coatings. High velocity air-fuel process (HVAF) is an alternative process, shown to be superior regarding corrosion protection and production costs. HVAF can deposit coating with shorter dwell time and lower temperature, producing coating with lower oxide content. This paper presents the use of HVOF and HVAF process to deposit FeCrMnSiNi and FeCrMnSiB coatings, studying the resistance against corrosion and cavitation in comparison to 316L HVOF coating. Microstructure was analyzed by XRD, microscopic means and mechanical testing. Cavitation and corrosion behavior of the coatings were also studied comparatively. HVAF coatings presented lower porosity and oxide levels, as well as higher hardness values, compared with the coatings deposited by HVOF process. The HVAF process presented better cavitation resistance than HVOF coatings. The FeCrMnSiNi HVAF coating had the best corrosion protection performance between the developed alloys.
Large Size Fe-Based Bulk Metallic Glass Composite Prepared by Additive Manufacturing via HVOF Thermal Spraying
Authors: Wang W. , Zhang C. , Liu L. 
Published: November 2022

Abstract
Bulk metallic glasses (BMGs) are a novel class of metallic materials with disordering atomic structure and excellent mechanical and chemical properties, and are promising for various industry applications. BMGs are usually fabricated by copper-mould casting due to the requirement of fast cooling rate for the obtainment of amorphous structure. However, this casting approach has the limitation for preparation of large size samples (the biggest Fe-based BMG obtained so far is less than 16 mm diameter). In this work, the conventional high velocity oxy-fuel (HVOF) thermal spraying technique was utilized as a novel additive manufacturing route to create large size Fe-based BMGs and BMG composites. It will be reported that a large size of 20x20x20mm BMG (Fe48Mo14Cr15Y2C15B6 (at%) ) and big plate of 100×100×5 mm of Fe-based BMG composites reinforced with 50vol% 316L stainless steel powders was successfully prepared by HVOF thermal spraying. Both BMG and BMG composite showed very dense structure (porosity less than 0.4% ) and good mechanical properties, Especially, BMG composite reinforced with 316 L stainless steel exhibited a yield strength of 1.8 GPa and compressive plastic strain of 2%. More importantly, this Fe-based BMG composite exhibited good toughness of KJ=21 MPa m1/2, which is almost 4-times higher than that of as-cast BMG. This present work indicates that HVOF thermal spray can become a versatile technique for preparation of large size of bulk metallic glasses and composites with desired properties.
On the Validity of Continuum Computational Fluid Dynamics Approach in Very Low Pressure Plasma Spray Conditions
Authors: Ivchenko D. , Zhang T. , Mariaux G. , Vardelle A. , Goutier S. , Itina T. 
Published: November 2022

Abstract
Plasma Spray Physical Vapor Deposition aims to substantially evaporate a powder in order to produce coatings with microstructures ranging from lamellar to columnar. This is achieved by the deposition of fine melted powder particles and nanoclusters and/or vapor condensation. The deposition process typically operates at pressure ranging between 10 and 200 Pa. In addition to experimental works, numerical works help to better understand the process and optimize the experimental conditions. However, the combination of high temperature and low pressure with the appearance of shock waves resulting from the supersonic expansion of the hot gas in the low pressure medium, makes questionable the suitability of the continuum approach for modelling such a process. This work deals with the study of (i) the effect of the pressure dependence of the thermodynamic and transport properties on the CFD predictions and (ii) the validity of the continuum approach for thermal plasma flow simulation under very low pressure conditions. It compares the flow fields predicted with a continuum approach (ANSYS Fluent CFD code) and a kinetic-based approach using a Direct Simulation Monte Carlo method (DSMC, SPARTA code). It also shows how presence of flow gradients can contribute to the errors in the results for typical PS-PVD conditions.
Cold Spraying of WC-Co-Ni Coatings Using Porous WC-17Co Powders
Authors: Yin S. , Lupton T. , Meyer M. , Lupoi R. , Ekoi E. , Dowling D. 
Published: November 2022

Abstract
Cold spray has been successfully used to produce WC-Co coatings in recent years, showing great potential. However, due to the lack of sufficient Co matrix phase for plastic deformation, the fabrication of cold sprayed WC-Co coating naturally requires expensive propulsive gas or very high working parameters, significantly increasing the manufacturing difficulty and cost. This paper aims to use conventional high pressure cold spray to fabricate high-performance and cost-effective WC-Co-Ni coatings, and to clarify its formation mechanism. To achieve this objective, mechanically mixed porous WC-17Co and dense Ni powders were selected as the feedstock with different WC mass fraction, F1 (41.5 wt.%), F2 (64.5 wt.%) and F3 (74.7 wt.%). Working parameters were set at a moderate level (nitrogen, 3.0MPa and 350°C) to control the experimental cost. Experimental results showed that WC reinforcements had no phase transformation and were completely retained in the WC-Co-Ni coatings. The highest WC mass fraction was present in the F3 coating, reaching approximately 75% (equivalent to the feedstock), quite close to the cold sprayed WC-25Co coating. Fracture of WC-Co particles during the deposition process was found to be the reason for such high WC retainability, dominating the coating formation mechanism.
Fatigue Strength of Mg Alloy Coated with Al Coatings via In-Situ Shot-Peening Assisted Cold Spray
Authors: Wei Y. , Luo X. , Li C. , Li C. 
Published: November 2022

Abstract
In this study, pure Al coatings were deposited on ZK60-T5 Mg alloy substrates via in-situ shot-peening assisted cold spray in order to study the effect of the Al coating on fatigue behavior of coated samples. Fatigue behavior of the coated and un-coated samples has been investigated through experimental tests. The size and shape distribution of powders, microstructural characteristics of coatings and fractography of fatigue test samples have been studied using scanning electron microscopy. The average microhardness of pure Al coating is higher than 70 HV50. In order to obtain the fatigue S-N diagram for each set, coated and un-coated samples have been tested in a load-controlled condition. The tension-compression fatigue experiments reveal that the fatigue property of ZK60-T5 alloy coated with pure Al coatings has significantly deteriorated compared with un-coated samples.
Coupled Thermo-Mechanical Analysis of the Ceramic Thermal Barrier Coatings
Authors: Kokot G. , Jasik A. , Moskal G. , Białecki R. , Adamczyk W. , Kruczek T. 
Published: November 2022

Abstract
The paper is devoted to thermal and thermo-mechanical analysis of the plasma sprayed thermal barrier coatings (TBC). The temperature and stress distribution using the finite element method in the microscopic scale is presented. The finite element model is based on the microscopy scan (dimension 5mmx3.5mm) and represent three levels of barrier structure: basement AMS 5599,undercoat NiCrAlY and ceramic layers of ZrO2×8Y2O3, Gd2Zr2O7 and DCL (double ceramic layer) Gd2Zr2O7/ZrO2×8Y2O3 type. The layers material properties are fully temperature dependent and coupled thermo-mechanical analysis is performed. The numerical results will be compared with the experimental one.
An Investigation of the Corrosion and Cavitation Resistance of Different Thermally Sprayed Coatings in River and Marine Environments
Authors: Fedorova M. , Baldaev L. , Baldaev S. , Baldaev N. , Akhmetgareeva A. , Martyanova V. 
Published: November 2022

Abstract
To evaluate the corrosion resistance of various coatings applied by the flame spraying method, and to compare their protective properties in sweet- and sea-water samples with seven types of coatings were made, one of them is paint, used to coat ship’s bottom. SEM, Neutral spray salt, according to ASTM B117, erosion-corrosion (E-C) tests in sweet- and sea-water were carried out. The test results showed that coatings based on zinc alloys and polymer are much more effective than standard epoxy coatings and can be compared with expensive zinc-filled paints, because the latter require frequent repairs and repainting. Moreover, the developed coatings are supposed to protect against fouling. At the moment, the fouling tests are continuing.
A Review of Utilization of Niobium and Tantalum for the Enhancement in Corrosion Resistance and Biocompatibility of Bio-Implants
Authors: Singh G. , Singh Sidhu B. , Singh B. 
Published: November 2022

Abstract
A bio-implant is a medical device used to support, replace or enhance a biological structure. Bio-implants have incalculable importance for mankind due to their crucial applications in situations like heart diseases, joint replacements, bone fixation and bone replacements etc. The materials which are used to manufacture bio-implants are generally called biomaterials. Corrosion and biocompatibility of biomaterials are the two issues, which are needed to be addressed to enhance the life span of the bio-implants. Various strategies were used to enhance the performance of biomaterials; however surface modification and alloying are the two main strategies among them. To employ these two strategies; various ceramic, metallic and composite materials were utilized as coatings and alloying elements with different biomaterials. Among all these materials, Niobium and Tantalum metals are studied by various researchers and proved to improve the corrosion resistance as well as biocompatibility of the bioimplants. This article gives a systematic overview of research work carried out in the area of bio-implants by utilizing Niobium and Tantalum for the enhancement of corrosion resistance and biocompatibility.
Plasma Processing of AB2 Alloy as Negative Electrode Material for NiMH Batteries
Authors: Onur Şahin E. , Eyovge C. , Öztürk T. 
Published: November 2022

Abstract
The present work deals with a Laves phase C14 AB2 alloy, namely (TiZr)(VNiMnCrSn)2. The alloy in many ways is a good alternative to a rare earth AB5 alloy with a superior capacity reaching a value of 400 mAh/g. A drawback with this alloy is that it is difficult to activate and therefore it is desirable to develop processing techniques which would readily activate the alloy. In this study we have plasma processed the alloy so as to see if this processing would exercise a positive effect on activation. AB2 powder was therefore fed to plasma torch with 25 kW power. The powders of -325 mesh had a range of particles sizes, the finer ones were evaporated and condensed into nanoparticles less than 100 nm in size. The larger ones spheroidized and were collected in the form of two groups of powders. We have characterized all three groups of powders both chemically and the latter two in terms of electrochemical performance.
Microstructural and Mechanical Investigations of Dissimilar Metal Joints of T91 and T22 Ferritic Steels
Authors: Mittal R. , Singh Sidhu B. 
Published: November 2022

Abstract
Ferritic steels are commissioned as one of the preferred structure materials for the boilers of nuclear and thermal power plants. The mechanical characterization and microstructural evolution of shielded metal arc welded dissimilar joint between ferritic SA213T91 (T91) and ferritic SA213T22 (T22) steels has been investigated by virtue of microstructures, micro-hardness, XRD and SEM/EDS analysis. Comparative performance of distinctive zones in the weldment i.e. heat affected zone, base metal and weld pool has been explored. The T91 HAZ and T22 HAZ zones of the weldment are observed to have high micro-hardness by virtue of martensitic morphology along with the presence of delta ferrite in T91 HAZ and carbide as well as intermetallics in T22 HAZ.
The Effect of Splats Morphology and Post-Treatment on the Microstructure of Sprayed Coating
Authors: Pakseresht A. , Shahbazkhan A. 
Published: November 2022

Abstract
In the thermal spray process, particulate materials can be melted by plasma atmosphere due to its high local temperature from 8700 °C to 15,000 °C. Therefore, the material powders turn into droplets after being melted by injection into the hot flame. Molten droplets are accelerated toward a substrate and form the splats which quickly solidify; finally, the film is formed by pile-up splats. Splat morphology and post treatment can determine the microstructure, mechanical and physical properties of the coating. In this study, BaTiO3 films were deposited onto a mirror polished stainless steel substrates kept at room temperature and 500 °C. At the elevated temperatures, the desorption of adsorbates and condensate at the substrate surface are the most important factor which change the morphology of the splats, from irregular- splash morphology to disk-like shape. Splat morphology can determine deposit microstructure and improve the coating properties. The morphology of individual splats and the post treated films were studied using scanning electron microscopy. Results indicated that the porosity in the film produced at room temperature was higher than that in the film deposited on the heated substrates. Also, post heat treatment can improve coating properties