bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of special physical fitness of qualified acrobatic rock n' roll athletes by means of functional training
Authors: Gumeniuk Sergii , Kyzim Petro
Published: June 2023

The article is devoted to the issue of improving the special physical fitness level of qualified acrobatic rock and roll athletes of the category "main class contact style" due to functional training tools. The experts consider purposeful functional training as one of the effective means of improving the special physical fitness of athletes. The lack of scientific-methodical and special literature regarding the functional training of qualified acrobatic rock and roll athletes determined the relevance of this research. The purpose is to experimentally investigate the improvement of special physical fitness of qualified acrobatic rock and roll athletes by means of functional training. The qualified acrobatic rock and roll athletes (seven sports couples: female partners n=7, male partners n=7), aged 15-22, the members of the Ukrainian acrobatic rock-n-roll National Team in the "adult" age category ("main class contact style") were involved into the research). The qualification of the research participants: master of sports of Ukraine, master of sports of Ukraine of international class. As the result of inclusion in the training process of qualified acrobatic rock and roll athletes developed functional training complexes were statistically significant changes in all selected tests (p < 0.05; p < 0.01). It was found that the level of special physical fitness of qualified acrobatic rock and roll athletes is positively affected by the inclusion of functional complexes in training process. This research presents functional training complexes developed for athletes of the "adult" age category, for the first time, which supplemented the methodology for improving the special physical fitness of acrobatic rock and roll athletes of different age categories.
Analysis of indicators of psychological qualities of military officers under the influence of factors of military and professional activities
Authors: Oderov Artur , Pervachuk Oleh , Lesko Orest , Pylypchak Vasyl , Romaniv Ihor , Andreychuk Volodymyr , Guba Anatolii , Тymochko Oleksandr , Paievskyi Volodymyr
Published: June 2023

The constant involvement of military personnel in the performance of duties in extreme conditions can contribute to maladaptation, a decrease in the body's adaptability to various environmental conditions, neuropsychological overstrain, and the emergence of persistent negative mental states in them. Therefore, the problem of forming the psychological readiness of servicemen of the Armed Forces of Ukraine to perform the tasks of military and professional activity in today's conditions is urgent, because not only the effectiveness of the professional activity of servicemen, but also their personal safety depends on such readiness.

The system of military-professional training of personnel is dynamic and constantly improving. A number of scientists claim that the most important direction of development and improvement of the system of military activity of soldiers is the development of certain methods and means that meet the requirements of the modern concept of the development of methods of military struggle, which are based on the formation of the necessary professional skills and abilities for successful adverse conditions of combat activity and military service.

The question of forming the psychological preparedness of military personnel for actions in extreme situations, which are not only combat operations, but also certain tactical exercises, shooting with various types of weapons, changing the deployment and location of units, etc., remains relevant. It is physical training and means of hand-to-hand combat that can, to a certain extent, ensure the high-quality formation of the readiness of servicemen to act effectively in this or that extreme situation arising in the conditions of military service.
Аpplication of game tactics analysis in sports games on the example of tennis
Authors: Khanyukova O.V. , Yakovenko A.V.
Published: June 2023

The article focuses on the current state of various means, methods and systems used in tennis to analyze the tactical activity of players. The purpose of the study is to study modern approaches to the analysis of tactical activity in sports games on the example of tennis. Research methodology: analysis of special, scientific and methodological literature, analysis of computer programs and applications for the use of fixing tactical actions, systematic method, generalization and systematization of data. Results of the study. In the course of studying scientific and methodical literature and modern technologies it has been found that there are several analysis systems for conducting a qualitative and effective analysis of tennis players' tactical actions. One of them is a notational analysis, which can be both manual and computerized. This method can be considered quantitatively consistent and reliable. Areas where it can be applied in tennis: tactical analysis, technical analysis, movement analysis, database and modeling. The article pays special attention to computer programs, which can be divided into two broad categories of tracking and tagging systems. In addition, the article presents the analysis of modern devices and applications that also belong to the category of tracking systems and are particularly popular among coaches and players for training and constant monitoring of the training and competitive processes of athletes. Conclusion. The existing means, methods and computer programs for analyzing the tactical actions of tennis players are diverse, modern, useful and widely used by coaches and players in training and competitive activities.
Approbation of the program of individual physical training of future officers using modern fitness technologies
Authors: Khomenko Oleksandr , Drahunov Dmytro , Butenko Anton , Solomakha Andrii , Nepomniashchyi Oleksandr , Gunbina Svietlana
Published: June 2023

Summarizing the results of the analysis of scientific literature, it was established that the existing system of individual physical training of future officers needs scientifically based transformation in accordance with today's requirements. In addition, the members of the scientific research group found an insufficient number of scientific works devoted to solving the practical problem of forming the physical readiness of future officers in the system of individual physical training using modern fitness technologies (exercise equipment). This emphasizes the relevance and practical component of the chosen direction of scientific research.

The main goal of the study is the approval of the program of individual physical training of future officers using TRX training loops (modern technical means of training).

As a result of an empirical study, we tested the program of individual physical training of future officers of the NGU using TRX training loops (modern technical means of training). When comparing the indicators obtained as a result of the empirical study (before and after the approval of the experimental program with an emphasis on the use of TRX training loops and modern training equipment), it was established that, that the results obtained at the end of the pedagogical experiment in the studied groups increased relative to the initial data, and these differences are mostly reliable (Eg, P≤0.05). Prospects for further research in the chosen direction of scientific research include the development of an experimental program of individual physical training of female cadets using TRX training loops (modern fitness technologies).
Formative assessment of children's learning results in physical culture lessons in New Ukrainian School
Authors: Yarmoshchuk Olena , Vasylyuk Vasyl , Hryhorovych Oleksandr
Published: June 2023

The thesis analysed modern methodical approaches to the assessment of educational achievements of students in physical education lessons at the New Ukrainian School at various stages of education. The main determinants had identified of the activity of the physical culture teacher in relation to the organization of formative assessment

Furthermore, in the process of work, it had found that the barriers to the wider use of formative assessment are: the discrepancy between formative assessment and final tests, which are designed to ensure the accountability of schools regarding the educational achievements of students; the lack of consistency between assessment and evaluation at the school and classroom levels and the perception that formative assessment is too resource-intensive and time-consuming to be practical.

The methodology of formative assessment techniques is justified. Assessment in physical education is carried out in the following areas: cognitive domain - what students know and understand; health-related physical fitness - improvement of physical fitness levels; psychomotor skills - what students can do and perform; affective domain - attitudes and beliefs towards the subject. It is noted that assessment in the affective domain involves: identifying behaviors; communicating actions (indicators) that are acceptable for students to meet the expectations regarding the assessed characteristics/behavior; using checklists, rating scales, journals, event records, exit slips, written tests. General behavioral characteristics include: effort (willingness to participate); fair play (sportsmanship); readiness to cooperate (teamwork). These characteristics may have different significance for different individuals, so it is the teacher who decides which characteristics/behaviors are most important for the lessons.
Bond Coat Engineering Influence on the Evolution of the Microstructure, Bond Strength and Failure of TBCs Subjected to Thermal Cycling
Authors: Lima R. S. , Marple B. R. , Nagy D.
Published: June 2023

Different thermal spray technologies were used to apply CoNiCrAlY bond coats to Inconel substrates. Powder compositions were the same in all cases and particle size recommendations were followed for each torch. YSZ topcoats were deposited via APS on bond coat samples selected based on roughness, porosity, residual stress, oxidation, and isothermal TGO growth. The TBCs were furnace cycle tested for 10-1400 cycles as well as to failure and changes in bond strength and TGO thickness were recorded. It was observed that bond strength values, which are relatively stable during thermal cycling, decrease significantly just before failure brought on by topcoat spall off.
Shrouded Plasma-Sprayed Cr3C2-NiCr Coatings: Effect of Shroud-Substrate Distance
Authors: Matthews S.
Published: June 2023

During heat treatment of Cr3C2-NiCr thermal spray coatings, regions of carbide dissolution have been observed to precipitate very small grains that grow into finely structured carbide networks. This study investigates the potential of developing tailored submicron carbide composites based on that process. The approach taken is to spray a conventional Cr3C2-NiCr powder under high-power plasma conditions to generate a supersaturated solid solution of Ni-Cr-C from which carbides could be precipitated via heat treatment. Preliminary trials assessed the effect of a broad range of plasma parameters to determine what conditions generate the greatest carbide dissolution with the lowest carbon loss. Follow-up trials investigated the most promising parameters in more detail to determine the effect of spray distance, with and without shrouding, on carbon loss and carbide dissolution. This paper presents the results from one of these trials in which an Ar-H2 plasma was sprayed with a low-velocity nozzle. Gas shrouding had a minimal effect on carbide dissolution but was effective in reducing air entrainment in the plasma and the degree of decarburization.
Interface Fracture Characterization of Plasma Sprayed and HIP Bonded Zr Coatings on U-Mo Sheet using Bulge Testing
Authors: Hollis K. , Liu C. , Leckie R. , Lovato M.
Published: June 2023

This study demonstrates the use of bulge testing to evaluate fuel plates for high-performance nuclear reactors. Uranium-molybdenum alloy substrates were plasma sprayed with zirconium and clad between aluminum sheets by hot isostatic pressing. The coated-and-clad samples were cut into disks, the top cladding was thinned, and a small hole was milled through the bottom cladding. The samples were then placed in a pressure cell and a syringe pump was used to inject distilled water through the hole in the bottom Al sheet. Two cameras measured bulge height while fluid pressure was simultaneously recorded. Test results show that all failures occurred at the plasma-sprayed Zr/U-Mo interface rather than the HIP-bonded Zr/Al interface. It is also shown that the use of transferred arc (TA) cleaning prior to spraying improves both failure pressure and initiation fracture toughness, especially under high ac current. TA cleaning facilitates the formation of strong diffusion bonds by removing oxide from the substrate and increasing interface temperature.
Optimization of an Emulator Based on Nonlinear Auto Regressive Model with Exogenous Inputs for an Atmospheric Plasma Spray Torch
Authors: Liu T. , Planche M.-P. , Deng S. , Montavon G.
Published: June 2023

The primary aim of this work is to develop an emulator to accurately simulate the dynamic behavior of a plasma torch. To that end, a nonlinear autoregressive model with exogenous inputs was designed around a mono-cathode torch used for atmospheric plasma spraying. Operating parameters such as current and gas flow rate were used as input variables and in-flight particle characteristics were used as output variables. In order to compensate for unstable and random process phenomena, data smoothing is used to decrease signal noise and improve data relevance. This is a key step as it allows most of the in-flight particle properties to be processed. Prior to implementation in the emulator, the smoothed data are optimized to get the best possible match with actual measured values. With the refined data, the difference between simulated and measured particle temperature and velocity is less than 3%.
Influence of Welding HAZ Stresses on Adhesion Strength of APS Ceramic Coatings
Authors: Barr J. , Estrada C. , Harrison J. , White B.
Published: June 2023

The purpose of this study is to determine if a GTAW (TIG) repair weld under an APS ceramic coating would cause a reduction in adhesion strength. Two stainless steels and a titanium alloy were selected for the study. For each material, 300 buttons were machined and further processed in groups of 50 through the application of one-pass, three-pass, or full pad welds. Welded buttons were lapped parallel to within 0.0002 in. and their lengths were compared with measurements obtained from buttons that had not been welded. NiCrMo bond coats were applied by HVOF spraying to both welded and unwelded samples, which were then top-coated with a ceramic layer (Cr2O3, Cr2O3-Al2O3, or TiO2) deposited by air plasma spraying. A ten-cycle heat treatment was conducted on half of the samples to determine if the weld would amplify thermal expansion stresses. Based on adhesion test results, the welding had no measurable effect on adhesion strength nor did the heat treatment. Heat input from the HVOF flame and the plasma jet was sufficient to reduce weld-related solidification stresses.
Cold Spraying of Cu-Al-Bronze for Cavitation Protection in Marine Environments
Authors: Krebs S. , Gärtner F. , Klassen T.
Published: June 2023

The present study investigates the microstructure and properties of cold spray coatings produced from gas-atomized CuAl10Fe5Ni5 powders. To obtain information relevant to ship rudder cavitation-erosion performance, GL-A shipbuilding steel, equivalent to S235, was chosen as the substrate material. Thick Cu-Al-bronze coatings were deposited on grit-blasted plates using a wide range of parameter sets with different powder treatments, nozzle geometries, gas and substrate temperatures, and particle impact conditions. Coating samples were examined via SEM and XRD analysis, cavitation tests were performed, and bond strengths were measured. Powder and single impact morphologies were also investigated and, along with coating properties and structures, are correlated with spraying conditions. The results indicate that cold sprayed bronze coatings have good potential for ship rudder protection.
Characterization and Optimization of Cold Sprayed Nickel and Nickel-Based Alloys on Aluminum and Steel Substrates for Corrosion Protection and High Temperature Applications
Authors: Lubkowitz S. , Trenkle F. , Luth J. , Hartmann S.
Published: June 2023

In this study, nickel and Inconel coatings were deposited on aluminum and steel substrates by cold gas spraying. Fine, standard, and coarse nickel powders and two standard Inconel (625 and 718) powders were selected as feedstock materials and sprayed at different gas pressures and temperatures. A coaxial air-cooled nozzle was used in spray trials, except for the fine Ni powder, which required a water-cooled nozzle to prevent clogging at high temperatures. Coating microstructures were examined and various properties were measured including shear strength, adhesive tensile strength, hardness, and porosity. Cross-sectional images of different coating samples are presented and discussed along with test results.
Corrosion Resistant Coatings for Cylinder Bore Applications in Passenger Car Engines
Authors: Ernst F. , Kube D. , Xavier F.-A. , Schmid J.
Published: June 2023

In this study, two high-Cr stainless steel feedstocks and a post-spray honing process are evaluated for potential use on cylinder running surfaces in passenger car engines. The two materials, X12 CrNi 25-4 and X6 Cr17, were deposited by plasma transferred wire arc (PTWA) spraying on aluminum cylinder bore surfaces that were mechanically roughened prior to coating. The coatings were then honed to a mirror finish using progressively finer diamond tools. Coating surfaces were analyzed by SEM and REM imaging, roughness profiles were recorded, and coating hardness and porosity were measured. The results are presented and discussed along with recommendations for additional work.
Columnar Structured Thermal Barrier Coatings (TBCs) by Suspension Plasma Spraying (SPS)
Authors: Schlegel N. , Ebert S. , Mauer G. , Vaßen R.
Published: June 2023

In this study, a suspension containing Mg-Al-spinel nanopowder was deposited on bond-coated IN738 and stainless steel disks by suspension plasma spraying with and without substrate cooling. Coating surfaces and cross-sections were examined by SEM, EDS, and XRD analysis and thermal cycling tests were performed. SEM images of coatings obtained on cooled stainless steel show a unique columnar microstructure with a cauliflower-like surface. XRD spectra of the nanopowder and coatings revealed evidence of phase changes in the material deposited on cooled substrates. In preparing samples for thermal cycling tests, a YSZ layer was deposited on bond-coated IN738 prior to spraying the suspension. Double-layered Mg-Al-spinel/YSZ thermal barrier coatings produced on cooled substrates exhibited a thermal cycling lifetime of 2000 cycles at 1390°C, compared to 101 cycles for the TBCs sprayed without substrate cooling. The superior performance of the TBCs sprayed with substrate cooling is attributed to the densification of the coatings, revealed by SEM images, and possibly the formation of CaO-6Al2O3 needles and Al2O3 precipitates as identified by EDS measurements.
Transfer of Micro-Structures by Transplantation of Thermal Sprayed Coatings
Authors: Knödler P. , Peuker A. , Freiburg D. , Otten M. , Möhwald K. , Biermann D.
Published: June 2023

Manufacturing a die-cast workpiece with a thermal spray coating usually requires multiple steps. An alternative approach demonstrated in this study integrates the spray process into a high-pressure die casting step, eliminating the need for surface preparation and post processing of the coating. To achieve this, the coating is applied to a mold insert rather than the workpiece. During pressure casting, the melt infiltrates the coating and thus creates a joint. Depending on the coating and substrate, a bonding connection similar to brazing is possible. The ability to manufacture coatings this way makes it possible to coat inside diameters well below the limit of an internal spray gun.
Mechanical Properties of Cu-Ag Alloys Deposited by Cold Spray
Authors: Coddet P. , Verdy C. , Coddet C. , Debray F.
Published: June 2023

This work focuses on the properties of Cu-Ag alloys deposited by cold spraying. Helium was used as the carrier gas, accelerating particles to 823 m/sec, which is in the middle of the deposition window for Cu alloys. To avoid oxygen contamination, the gun was placed in a helium-filled chamber and a closed-loop circulating system was used to minimize helium loss. Deposition parameters were varied during spraying and their effect on hardness, tensile properties, residual stress, and porosity was assessed in as-sprayed and heat-treated samples. Ultimate tensile strengths of 450 MPa and yield strengths of about 420 MPa were obtained for the as-sprayed samples and it was shown that strength and ductility can be tailored by heat treating, reaching elongation values higher than 45%. An increase in deposition rate from 55 to 142 g/min was also achieved without a significant decrease in mechanical properties.
Relationships Between In-Flight Characteristics and Microstructural Properties of Plasma Sprayed Yttria Stabilized Zirconia
Authors: Sesso M. L. , Berndt C. C. , Wong Y. C. , Ang A. S. M
Published: June 2023

This study investigates relationships between in-flight particle characteristics and the microstructural properties of air plasma sprayed YSZ. Particle velocity and temperature were measured at different stand-off distances and contour plots were created. Coating porosity and hardness were measured and plotted over the same area. It is shown that in-flight particle characteristics are strongly affected by particle size distribution. Smaller particles in trajectories above the torch central axis were found to be 10 m/sec slower on average than larger particles in the center and lower section of the plume. The section of the plume with the highest temperatures and velocities is about 2 mm below the central axis and is shown to generate dense, hard layers with less than 7% porosity and hardness values on the order of 700 HV. Reynolds numbers determined from in-flight particle data also provide an indication of microstructural properties; where Reynolds numbers exceed 1000, coating porosity is less than 5%.
On the Dielectric Behavior of Annealed Plasma Sprayed Forsterite and Alumina Coatings
Authors: Lamarre J.-M. , Cojocaru C. V. , Legoux J.-G.
Published: June 2023

This study compares the dielectric properties of annealed forsterite (Mg2SiO4) and alumina coatings deposited on mild steel substrates by atmospheric plasma spraying. As-sprayed coating samples were electrically characterized then submitted to a series of one-hour annealing treatments at temperatures from 300 to 800 °F. After each treatment, impedance measurements were recorded over a frequency range of 30 to 100 kHz. An electrical model was fitted to Nyquist data (Im Z vs. Re Z) using a least-mean-square algorithm with a weighting function. Although impedance spectroscopy measurements were obtained at different temperatures, this paper focuses on the acquisition, modeling, and comparison of room temperature properties, particularly electrical resistivity and dielectric constant. It also compares the microstructure of as-sprayed and annealed forsterite and alumina coatings and discusses coating degradation mechanisms stemming from differences in CTE.
Residual Stress Analysis on Thermally Sprayed Coatings by Means of Optical and Mechanical Methods
Authors: Martínez García V. , Pedrini G. , Killinger A. , Gadow R. , Osten W.
Published: June 2023

The residual stresses present in coatings and layer composites are influenced not only by the thermal and mechanical loads generated during manufacturing, but also by the mechanical and thermophysical properties of the coating and substrate materials. In-process measurement of transient, process-induced stresses may thus enable the manufacturing of coated parts with a residual stress state that lies within a predefined application-oriented stress regime. This paper presents a quasi-nondestructive method by which such measurements may be obtained. A small amount of material is removed from the surface of a part by laser ablation, while optical interference sensors monitor surface deformation caused by stress relaxation and heating due to absorbed laser energy. The new method is evaluated by four-point bend testing using Al5754 plates coated with Al/TiO2 by atmospheric plasma spraying.
Quality Designed Twin Wire Arc Spraying of Aluminum Bores
Authors: König J. , Lahres M. , Methner O. T.
Published: June 2023

This paper describes the development and implementation of a twin wire arc spraying process used to apply iron-carbon alloy coatings to cylinder bores in aluminum engines made for high-performance luxury vehicles. It presents and analyzes measurement data that quantify the uniformity of the coatings and the speed at which they are applied. It also discusses key technological achievements and their impact on the coating process.
Ultra-Smooth Hardface Coatings Applied by Advanced HVOF Process
Authors: Ma X. , Ruggiero P.
Published: June 2023

This paper describes the development of a high-velocity oxyfuel (HVOF) spray process optimized for hardfacing components in aircraft engines and industrial gas turbines. Experiments show that the new process can produce WC-CoCr coatings with near-net-shape, ultrasmooth as-sprayed surfaces, and improved erosion resistance. Information obtained through particle diagnostics and other analytical methods is presented, showing how different process parameters influence coating microstructures, surface morphologies, and physical and mechanical properties. With appropriate process settings, hardface coatings can be produced that require only a surface finishing step.
Design of Experiment for Advanced Nanostructured WC-12Co Coating HVOF: Three-Point Bending Tests
Authors: Al-Hamed A. A. , Benyounis K. Y. , Al-Fadhli H. Y. , Yilbas B. S. , Hashmi M. S. J. , Stokes J.
Published: June 2023

In this study, a design of experiment (DOE) approach is used to investigate the influence of powder size and mixing ratio on the microstructure and properties of thermal spray coatings. Nano and micro sized WC-12Co powders combined in different proportions with Inconel 625 were deposited on carbon steel substrates by HVOF spraying. The resulting coatings are examined and the effect of different powder combinations on hardness and yield strength is assessed. Spraying procedures and test methods are described and the findings are discussed. Of the various coatings produced, one shows great promise for wear protection, particularly in oil and gas applications.
Optimization of Grit Blasting Conditions by Supersonic Air Spraying
Authors: Lyphout C. , Björklund S. , Boccaccio P.
Published: June 2023

This work assesses the feasibility of using a high-velocity airfuel (HVAF) gun both to grit blast and spray substrate surfaces. A design of experiments (DoE) approach was used to establish relationships between grit blasting variables, substrate surface conditions, and coating properties. Alumina was selected as the abrasive media, the substrates were HSLA steel, and CrC-NiCr and Fe-based powders were used to form the coatings. Uncoated and as-sprayed substrates were characterized based on hardness, residue levels, surface roughness profiles, and adhesion strength, which are correlated with mesh size, feed rate, offset angle, and standoff distance.
Influence of the Spray Gun Type on Microstructure and Properties of HVAF Sprayed Fe-Based Corrosion Resistant Coatings
Authors: Milanti A. , Koivuluoto H. , Vuoristo P.
Published: June 2023

The aim of this study is to evaluate the microstructure and corrosion properties of Fe-based coatings produced using different HVAF spray guns. Differences in microstructure, phase composition, porosity, oxide content, and corrosion behavior were observed among the coatings depending on the gun and spraying parameters. The results are presented and discussed in detail.
A 25 Year Exposure Test of Thermal Sprayed Zn, Al, and Zn-Al Coatings in Marine Environments
Authors: Kuroda S. , Uematus S. , Kato K. , Ichiryu Y. , Saitoh H.
Published: June 2023

This paper presents key findings from an ongoing study on the marine corrosion behavior of thermally sprayed zinc and aluminum coatings. Zn, Al, and Zn-Al layers of varied thickness were applied to twelve steel pipes by arc and flame spraying and subjected to different post-spray treatments such as sealing and painting. The pipes are mounted vertically on a test rig in the Pacific Ocean and have been inspected annually to record the appearance and thickness of the coatings. After 7 years, the Zn coatings began to show signs of degradation in the immersed portion of the pipe, although no such changes occurred with Al and Zn-Al coatings. After 18 years, heavily damaged sections of three pipes were removed and new pipe was welded in place. The repaired regions were coated with Al-5%Mg, which has performed well so far.
Improved Efficiency in Paper Making by Thermal Spray Coatings
Authors: Jungklaus H.
Published: June 2023

This paper discusses the different types of rolls used in paper machines, the functions and performance required of them, and recent improvements achieved with the aid of thermal spray coatings. It presents examples showing how metal and ceramic coatings applied by HVOF and plasma spraying have reduced operating expenses and extended roll life by stabilizing and improving various surface properties.
Pulsed Laminar Arc Jet Associated with Phase Injection of Suspension for Coating Elaboration
Authors: Krowka J. , Rat V. , Chazelas C. , Coudert J. F.
Published: June 2023

This paper presents a new approach to overcome arc plasma instabilities in suspension plasma spraying. The method employs a dc plasma torch with a large cathode cavity. This design modification reduces the Helmholtz frequency of the torch, resulting in a new oscillation mode with a very regular voltage signal. In the experiments, droplets of a TiO2 suspension are injected into the pulsed laminar arc jet in synch with the Helmholtz resonant frequency. Interactions between the plasma and droplets are observed by time-resolved imagine techniques and are discussed.
Production and Plasma Spraying of Cermet Powders TiC-NiCr with Given Volume Content of Carbide Ultra-Fine Inclusions
Authors: Solonenko O. P. , Chesnokov A. E. , Smirnov A. V.
Published: June 2023

This paper presents a method for producing TiC-NiCr cermet powders with particle sizes of 40-90 μm and 15-50% volume content of ultrafine carbide inclusions. The method is based on a combination of mechanoactivation of initial components and subsequent high-temperature self-propagating synthesis. TiC-NiCr powders with different amounts of carbide content were produced and their applicability for plasma spraying is assessed.
Properties and Comparison of WC-25/17/12Co Cold Spray Coatings onto Al7075-T6
Authors: Couto M. , Dosta S. , Guilemany J. M. , Putzier J.
Published: June 2023

This study evaluates the corrosion and wear resistance of WC-Co coatings produced by cold gas and HVOF spraying. Three WC-Co cermet powders varying in cobalt content were deposited on aluminum alloy substrates by both methods. The powders were characterized based on microstructure, particle size distribution, and phase composition, and the coatings based on cross-sectional microstructure, phase composition, and Vickers hardness. The coatings are also compared based on the results of ball-on-disk, rubber-wheel, and electrochemical testing, which shows that CGS has several advantages over HVOF spraying for the deposition of WC-Co coatings.
Plasma Spraying of Ceramics with Particular Difficulties in Processing
Authors: Mauer G. , Schlegel N. , Guignard A. , Jarligo M. O. , Rezanka S. , Hospach A. , Vaßen R.
Published: June 2023

This study deals with the deposition of coating materials that can be difficult to process by plasma spraying, including lanthanum and gadolinium zirconate, two pyrochlores of interest for thermal barrier applications, and lanthanum strontium cobalt ferrite (LSCF), a perovskite of interest for gas separation membranes. In addition to conventional atmospheric plasma spraying (APS), the feedstock powders were applied by suspension plasma spraying (SPS) and plasma spray-physical vapor deposition (PS-PVD). The spraying processes are described in detail along with the characteristics of the powders and coatings and the effects of various spray parameters on splat behavior and coating composition and structure.
Examination of the Origin of Intersplat Interface Debonding During Plasma Spraying of Ceramic Coating
Authors: Chen L. , Yang G.-J. , Li C.-X. , Li C.-J.
Published: June 2023

The aim of this study is to better understand the formation of nonbonded splat-to-splat interfaces in thermally sprayed ceramic coatings. To that end, the surfaces between splats in plasma-sprayed La0.5Sr0.5CoO3 (LSCO) coatings were examined and compared to free splat surfaces. The results show that free splat surfaces are relatively smooth, while adjacent surfaces at intersplat interfaces are quite rough. The observation implies that nonbonded splat-to-splat interfaces were never bonded, having fractured due to interface shear stress generated during splat cooling.
Phase Selection During Rapid Solidification of Plasma-Sprayed Alumina Splats on an Alumina Substrate
Authors: Yang E.-J. , Xin J.-J. , Li C.-J. , Wang G.-X. , Yang G.-J.
Published: June 2023

In earlier experiments, plasma-sprayed Al2O3 coatings were deposited on preheated Al2O3 substrates to study the effect of substrate temperature on splat formation and phase transformations. The aim of the present work is to develop a model to better understand the factors that affect phase selection during the solidification of Al2O3 splats. A model based on one-dimensional heat transfer and classic nucleation theory is presented and used to simulate the rapid solidification process and the influence of process parameters on phase selection. The model accounts for under-cooling phenomena, heterogeneous nucleation, and nucleation kinetics. The findings indicate that the relationship between initial substrate temperature and phase selection is primarily based on the catalytic effect of the alumina substrate on the nucleation of Al2O3 phases as a function of contact angle.
Wear Resistant HVOF Coatings for High Temperature Applications
Authors: Houdková Š. , Kašparová M. , Česánek Z. , Schubert J.
Published: June 2023

This paper evaluates and compares five wear-resistant coatings produced by HVOF spraying for high-temperature use. CrC-NiCr, CrC-CoNiCrAlY, Stellite 6, NiCrBSi, and TiMoCN-Ni coatings were sprayed on grit-blasted carbon steel substrates. Abrasive, sliding, and fretting wear resistance were measured and changes in microstructure and hardness due to high-temperature exposure were recorded. CrC-NiCr coatings exhibited the best wear properties, but the oxidation of carbides at high temperatures proved to be a problem. Based on test results, alternative coatings would include CrC-CoNiCrAlY for abrasive wear, Stellite 6 for erosive wear, and NiCrBSi for sliding wear.
Spray Plasma Processed ZrB2-Based Coatings for Oxidation Protection
Authors: Barré C. , Quet A. , Bianchi L. , Sanchez C. , Sauveroche A.
Published: June 2023

This work evaluates the potential of using a plasma spray process to introduce SiC into zirconia diboride ceramic coatings. Controlling the spraying of the ultra-refractory compound ZrB2 is the first challenge as it represents the matrix in which SiC particles will reside. To that end, the experiments focus on spraying parameters that influence the plasma jet and the nature of the precursor feedstock. The results show that ZrB2 coatings containing controlled amounts of SiC can be obtained through high-energy suspension plasma spraying. The ZrB2-SiC coatings will be evaluated in a high-temperature oxidative environment in future work.
New Types of Self-Lubricated Thermal Spray Coatings: The Use of Liquid Lubricants in a Metal Matrix
Authors: Espallargas N. , Armada S.
Published: June 2023

In this work, wire arc spraying is used to produce coatings in which oil-filled capsules are incorporated in the metal matrix. The coatings were deposited on carbon steel substrates using commercially available Zn-Al and FeNiCr alloy wires. The capsules were injected almost radially toward the substrate using an independent slurry feeder. No signs of degradation were observed during spraying and the coatings were able to keep a low coefficient of friction. Wear tracks produced by the steel ball used for friction testing were examined and volume loss was determined based on wear track profiles.
Multiscale Modelling of Microstructural Defects and Influence on Mechanical Properties and Wear Resistance of Thermal Spray Coatings
Authors: Laukkanen A. , Varis T. , Suhonen T. , Metsäjoki J. , Andersson T. , Laitinen T.
Published: June 2023

This work assesses the effects of defects in thermally sprayed chromia via multiscale modeling and imaging techniques. Defect distributions in coating samples are identified by way of image processing and synthetic 3D microstructures are generated from extracted statistical information. The properties of the microstructures are determined by subjecting them to simulated tensile testing, and the significance of different types of defects is evaluated through defect-containing coating models. The approach is able to handle complex defect morphologies, including pore, crack, and splat boundary clusters, making it a versatile tool for assessing the influence of defects on component performance.
Application of Dry-Ice Blasting in High-Velocity Oxyfuel Process for Deposition of Thick WC-Co Coating
Authors: Dong S. , Song B. , Hansz B. , Liao H. , Coddet C.
Published: June 2023

Residual stresses arising during high-velocity oxyfuel (HVOF) spraying usually impose a limit on coating thickness. In this work, dry-ice blasting is used in combination with HVOF spraying to produce thick WC-Co coatings characterized by compact microstructure, crystal refinement, high hardness, and excellent sliding wear resistance.
Plasma Sprayed Ce:YAG
Authors: Ctibor P. , Kubát J. , Pala Z. , Nevrlá B.
Published: June 2023

In this study, gas- and water-stabilized plasma torches were used to spray cesium-doped yttrium aluminum garnet (Ce:YAG) on different substrate materials and in large-area free-standing layers. The coatings were evaluated based on microstructure, crystallinity, and thermal stability, and tests were performed to measure porosity, hardness, phase composition, band-gap energy, and the presence of defects. Some coatings were also heat treated to determine how it changes their spectral response. The results of the examinations and tests are presented in the paper.
Surface Roughness of Plasma Sprayed Coatings: A Statistical Approach
Authors: Gan J. A. , Berndt C. C.
Published: June 2023

Thermal spraying produces coatings with relatively rough surfaces compared to other deposition methods. In this work, NdFeB coatings were deposited on stainless steel by plasma spraying at various standoff distances. Some of the coatings were also annealed. Surface roughness profiles of as-sprayed and heat-treated coatings were measured by contact profilometry and analyzed via statistical methods. The effect of standoff distance and annealing on roughness is discussed along with the significance of measurement direction and evaluation length.
The Effect of Severe Shot Peening as Pre/Post Treatment on Fatigue Behavior of Cold Spray Coating
Authors: Moridi A. , Hassani-Gangaraj S. M. , Vezzu S. , Guagliano M.
Published: June 2023

This study evaluates the influence of shot peening on the fatigue life of cold spray aluminum alloy 6082 coatings. A pneumatic blast machine with standard steel shot was used to peen both uncoated and coated substrates. Six test groups representing different treatment protocols were characterized in terms of residual stress, roughness, and rotating bending fatigue. The results show that the best fatigue performance is obtained by intense shot peening prior to cold spraying. Post-treatment shot peening, in contrast, had a detrimental effect as a large portion of the kinetic energy is absorbed in the coating, resulting in surface damage rather than further work hardening.
Development of Velocity Measurement Methods for Cold Sprayed Particle Clusters Using Particle Image Velocimetry Techniques
Authors: Sakata K. , Tagomori K. , Sugiyama N. , Sasaki S. , Shinya Y. , Yasuki M. , Sasaki H. , Nanbu T. , Takashima K. , Katanoda H.
Published: June 2023

In this investigation, particle image velocimetry (PIV) and direct imaging are used to measure particle velocities during cold spraying. Four feedstock powders were sprayed, including Ni, WC-Co, carbonyl Fe, and Cr steel. Multiple exposures at 500 ns intervals were used to measure in-flight particle velocities via direct imaging with a high shutter speed camera. Velocimetry measurements were made with a double-pulse laser and a high-resolution camera. With the minimum frame straddling time set to 100 ns, a maximum particle velocity of 1052 m/s was measured.
Micro-Scale Interface Strength Evaluation of Cold Sprayed Deposit
Authors: Ichikawa Y. , Watanabe Y. , Nonaka I. , Miura H.
Published: June 2023

The aim of this study is to clarify the factors that control the macroscale strength of cold spray coatings by evaluating local strength at the microscale. Using pure copper powder and high-pressure cold spray equipment, thick (15 mm) copper layers were deposited on aluminum substrates. The coatings were evaluated by SEM and EBSD analysis, then freestanding Cu specimens were fabricated in a FIB system, where in-situ micro tensile tests were carried out. The results are presented and discussed along with the role of microvoids.
Disorder and Bonding in Cold Spraying of Fe40Al
Authors: Cinca N. , Gärtner F. , Klassen T. , Guilemany J. M.
Published: June 2023

The aim of this work is to determine whether local disordering plays a role in the bonding of FeAl intermetallic coatings produced by cold spraying. XRD analysis of the powder and coatings revealed superlattice peaks, indicative of an ordered intermetallic structure. Nevertheless, locally disordered structures were detected in the deposits by TEM imaging. This may be related to a deformation induced order-to-disorder transformation due to the high strains involved in cold spraying, which is supported by comparing the magnetic properties of the deposits with those of HVOF sprayed coatings produced using disordered ball-milled feedstock.
Effects of Al Content and Addition of Third Element on Fabrication of Ti-Al Intermetallic Coatings by Heat Treatment of Warm Sprayed Precursors
Authors: Sienkiewicz J. , Kuroda S. , Minagawa K. , Murakami H. , Araki H. , Kurzydłowski K. J.
Published: June 2023

In this study, titanium and aluminum powders mixed in different ratios were deposited on stainless steel substrates by warm spraying. Microstructure and composition of as-sprayed and heat-treated samples were characterized and the effect of adding a third element was assessed. It was found that Al content has a major influence on the thickness and porosity of heat-treated Ti-Al coatings and that adding silicon to the powder mixtures reduces the melting point of Al, causing a loss of Al-Si particles during spraying.
Improvement of Delamination Resistant Properties for Thermal Barrier Coatings by Formation of Wedge-Like Thermally Grown Oxide
Authors: Hatta S. , Ogawa K. , Takanezawa T. , Yamazaki H.
Published: June 2023

Previous work on thermal barrier coatings (TBCs) has shown that Ce-containing bond coats promote the formation of a wedge-like interface oxide that improves delamination resistance. The oxide was found to form at temperatures greater than 1100 °C, which in many applications, may not be reached. In this study, TBC samples consisting of a YSZ topcoat and various cold-sprayed bond coats were prepared. In order to obtain a wedge-like thermally grown oxide (TGO), pre-oxidation was carried out for 20 h at 1100 °C prior to high-temperature testing for 1000 h at 1000 °C. It was confirmed that the pre-oxidation treatment produced a wedge-like TGO that continued to grow at 1000 °C, which improved delamination resistance as four-point bend tests showed. A wedge-like oxide was also observed in some TBCs exposed to temperatures of 1000 °C, without pre-oxidation.
Columnar Structured Thermal Barrier Coatings Deposited by Suspension Plasma Spraying
Authors: Tao S. , Zhong X. , Zhao H. , Zhao Y. , Li D. , Ding C.
Published: June 2023

This investigation evaluates the microstructure and properties of thermal barrier coatings produced by suspension plasma spraying. A YSZ suspension was injected axially into a plasma jet and deposited on a superalloy substrate with a CoNiCrAlY bond coat. SEM examination revealed a columnar microstructure with a network of vertical segmentation cracks and horizontal branching cracks. In furnace cycle testing, the TBCs withstood 166 thermal shock cycles with failure attributed to partial spallation of the columnar segments initiating at the edge and center of the coatings. The TBCs were also subjected to burner rig tests to assess thermal insulation properties and to heat treatments up to 1600 °C to evaluate thermal stability based on phase composition, grain size, and microhardness.
Healing of the Interface Between Splashed Particles and Underlying Bulk Coating and Its Influence on Isothermal Oxidation Behavior of LPPS MCrAlY Bond Coat
Authors: Zhang B.-Y. , Shi J. , Yang G.-J. , Li C.-X. , Li C.-J.
Published: June 2023

Thermally grown oxide (TGO) that naturally forms on bond coat surfaces plays an important role in determining the lifetime of thermal barrier coatings (TBCs). Splashed particles on thermally sprayed MCrAlY bond coat surfaces are weakly bonded to the underlying bulk coating, leading to the formation of mixed oxides that contribute to TBC failure. In this study, various heat treatments are used to modify the weakly bonded splashed particles on LPPS CoNiCrAlY bond coats in order to restrain the formation of mixed oxides and prevent associated failures.
Workplace Exposure to Nickel During Thermal Spraying Processes
Authors: Blättler M. A. , Pletscher C. , Miedinger D. , Koller M.
Published: June 2023

To assess workplace exposure to nickel during thermal spraying, an air quality study was conducted at a thermal spray facility between 2007 and 2010 and 22 thermal spray operators were monitored. Results show that certain activities and operations have the potential for high exposure to nickel compounds. It is also shown that the biological agent tolerance value (BAT-value) of water-insoluble nickel compounds can be respected if specific technical, organizational, and personal-protective measures are consistently implemented.
Process Control of Thermal Spraying Processes by Means of Acoustic Emission Analysis
Authors: Tillmann W. , Abdulgader M. , Wang G. , Zielke R.
Published: June 2023

This study demonstrates an experimental setup in which acoustic emission sensing is used to monitor a twin wire arc spraying (TWAS) process. Emitted acoustic signals were recorded by broadband sensors attached to the spray nozzle and mounted under the substrate. Sensor outputs were converted from the time domain to the frequency domain by fast Fourier analysis. Acoustic emission amplitude plots were produced and are correlated with gas pressure, arc voltage, in-flight particle velocity and temperature, coating thickness, and crack formation due to cooling.