bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of an Inductively Coupled Plasma for the Synthesis of Nanoparticles
Authors: Bolot R. , Coddet C. , Shreuders C. , Leparoux M. , Siegmann S.
Published: September 2022

Nanoparticles show novel properties compared to the bulk material of same chemistry. The small size is responsible for many changes in the thermo-physical properties. Thus, there was an increasing interest in nanomaterials since the past five years. Among other methods, inductively coupled plasma (ICP) torches can be used for the synthesis of nanoparticles. In this process, the precursor material is vaporized in a first step in the plasma core. In a second step, nucleation and condensation occur in the synthesis chamber where the plasma gets colder and form high-purity nanoparticles, the growth of which is stopped by gas quenching. From their low velocity and high temperature, induction plasmas are particularly adapted for this application. Numerical modeling is a good way to achieve a better knowledge and understanding of the process. In the present paper, a two-dimensional model of an inductively coupled plasma torch was developed and validated on the basis of comparisons with data obtained by some other authors. Finally, the current frequency (13.56 MHz), pressure level (400 mbar) and gas flow rates were adjusted for the specific conditions of nanoparticles synthesis.
Unsteady 3D Large Eddy Simulation of an Ar-H2 Plasma Jet: Analysis of Initial Results
Authors: Balmigere G. , Meillot E. , Vincent S. , Caltagirone J.-P.
Published: September 2022

Suspension plasma spraying (SPS) is of great interest for the realization of thin nanostructured coatings. The thermokinetic phenomena involved in the SPS process, from the plasma/liquid interaction to the growth of the coating are difficult to forecast and experiment. The present work focuses on the 3D simulation of an Ar-H2 (45-15 slm) plasma jet issuing into ambient air. A large eddy simulation model accounts for turbulence and provides us with the instantaneous temperature and velocity fields of the plasma flow. The results obtained with the CFD library AQUILON are compared to experimental ones as well as previous simulations realized with a commercial software.
Molecular Dynamics Simulation of Flattening Process of a High-Temperature, High-Speed Droplet: Influence of Impact Parameters
Authors: Shimizu J. , Ohmura E. , Kobayashi Y. , Kiyoshima S. , Eda H.
Published: September 2022

Three-dimensional molecular dynamics simulation was conducted to clarify at an atomic level the flattening process of a high-temperature droplet impacting a substrate at high speed. The droplet and the substrate were assumed to consist of pure aluminum, and the Morse potential was postulated between a pair of aluminum atoms. In this report, the influences of the impact parameters, such as the droplet velocity and the droplet diameter on its flattening behavior were analyzed. As a result, following representative conclusions were obtained: (1) the flattening ratio increases in proportion to the droplet velocity and the droplet diameter; (2) the flattening ratio for nanosized droplet can be rearranged by the same dimensionless parameters of the proper physical properties, such as the viscosity and the surface tension, as those used in the macroscopic flattening process.
Comparison of Molecular and Argon Gases for Plasma Spraying
Authors: Pershin L. , Chen L. , Mostaghimi J.
Published: September 2022

Thermal spray torches commonly use argon for plasma generation. Low thermal properties of argon, however, limit the thermal efficiency of the torches. Use of molecular gases, which must dissociate before ionization, requires larger energy input resulting in enthalpy increase of the plasma. In this paper, the effect of various gas compositions (Ar, Ar+H2, and CO2+CH4) on the torch voltage-current characteristics, power and thermal efficiency were studied. At the same time, in-flight YSZ particle conditions were compared. The higher thermal conductivity and efficiency of CH4+CO2 gas mixture produce more favorable sprayed particle conditions, in particular temperature. At a 50mm spray distance, YSZ particle temperatures were 2470°C and 2896°C for Ar+H2 and CH4+CO2, respectively. Typical arc voltage for the torch operating in CO2+CH4 was 130-180V compared to 45-60 V for Ar+H2. Thermal efficiency was also 20-40% higher.
Study on Cold Spraying of Al-based Brazing Alloys
Authors: Lugscheider E. , Bobzin K. , Zhao L. , Ernst F. , Zwick J.
Published: September 2022

The cold spray process is interesting for brazing technology due to its special properties: low oxidation of spray materials and rupture of oxide scales on the substrate and particles surfaces during deposition. In the present study, two brazing alloys AlSi12 and AlSi10Cu4 were deposited onto 6063 and 3003 aluminium alloys using the cold spray process. The influence of the spray parameters on the particle velocity was investigated by means of DPV 2000. The influence of spray materials and parameters on coating build up and on coating microstructure was investigated. Some of the AlSi12 coated samples were heat-treated at 500 and 600 °C to investigate the effect of the rupture of oxide scales on the diffusion processes. Some of the AlSi12 deposited samples were brazed under argon atmosphere using a flux or without any fluxes. The results show that the process gas temperature influenced the particle velocity and the deposition behaviour of the powders significantly. The AlSi12 powder showed a much better deposition behaviour than the AlSi10Cu4 powder. Due to the rupture of oxide scales, silicon in the brazing alloy coating could diffuse into the substrate. The brazed samples show a very good bond between the substrate and the brazing alloy.
Investigation about the Chrome Steel Wire Arc Spray Process and the Resulting Coating Properties
Authors: Wilden J. , Bergmann J.P. , Jahn S. , Knapp S. , van Rodijnen F. , Fisher G.
Published: September 2022

Nowadays wire arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications. In order to optimize the process parameters and to evaluate the effect of the spray parameters DoE based experiments have been carried out as well. In this paper, the effects of the process parameters of spray current, voltage and atomizing gas pressure on the particle jet properties of mean particle velocity and mean particle temperature as well as plume width are presented. To monitor these values the AccuraSpray system was used. The properties of the coatings with regard to morphology, composition and phase formation are included as well. These investigations are part of the development of new power supplies and the enhancement of spray parameter range. As a result of these experiments the spray parameters can be adjusted according to the requirements of the chromium steel coatings.
New Process Adapted Power Supplies for Wire Arc Spraying
Authors: Knapp S. , van Rodijnen F. , Fischer G.
Published: September 2022

The precondition of a cost efficient wire arc spraying process is an ideal process setup according to the wire material. Modern power supplies are equipped with electronic control circuits to ensure stable arc conditions at the wire tips. This is necessary for high quality wire arc sprayed coatings. The key factors to achieve this are the arc energy and fluid mechanics as well. By the use of a PID controller to maintain set spray parameters, it is possible to reduce the spray voltage down to 15 V for zinc as feedstock material. Furthermore temperature dependent parameter fluctuations can be compensated with the electronic controller, while working at maximum capacity with one hundred percent duty cycle. The paper discusses the influence of a new power supply with regard to the process stability and the enhancement of former power supply based process limitation as well as the operator guidance.
A New Method for the Production of Particle Reinforced Coatings
Authors: Wilden J. , Bergmann J.P. , Jahn S. , Reich S. , Knapp S. , van Rodijnen F. , Fischer G.
Published: September 2022

A method for the production of particle reinforced coatings by wire arc spraying will be presented in this paper. This technology is based on twin-wire electric arc spraying (TWEA) process. Here, additional particles were injected into the atomizing gas stream and sprayed in a non molten state along with wire feedstock material onto the substrate. According to the reinforcing particles, the process can be applied to produce coatings with a high wear resistance as well as a high surface roughness. In a wide range of applications, these coating characteristics are required. Due to economic constraints, coatings of large surfaces have to be done in short times at low costs. Based on wire arc spraying, the thermal spray process with the highest deposition performance, the mentioned industry requirements can be fulfilled.
Influence of Microstructure on the Thermal Cycling Performance of Thermal Barrier Coatings
Authors: Vaßen R. , Stöver D.
Published: September 2022

Thermal barrier coatings (TBCs) with different types of microstructures were produced with the atmospheric plasma-spraying (APS) process. The investigation includes a variation of the micro-crack density and of the porosity level. In addition, also segmented TBCs were produced. Finally, also PVD-TBC systems have added to the investigation. The different TBC systems were cycled in a natural gas/oxygen burner rig with a surface temperature of about 1250°C and a bond coat temperature of about 1100°C or below. The use of relatively low surface temperature guarantees a failure mode close to the bond coat promoted by the growth of the thermally grown oxide (TGO). After failure, metallographic inspection was made to determine the thickness of the TGO layer and the β-phase depleted zone. In addition, the crack path was analyzed and compared for the different microstructures.
Thermal Fatigue Behaviour of Thick and Porous Thermal Barrier Coatings Systems
Authors: Scrivani A. , Rizzi G. , Bardi U. , Giolli C. , Muniz Miranda M. , Ciattini S. , Fossati A. , Borgioli F.
Published: September 2022

High temperature thermal fatigue causes the failure of Thermal Barrier Coating (TBC) systems. This paper addresses the development of thick TBCs, focusing attention on the microstructure and the porosity of the Yttria Partially Stabilized Zirconia (YPSZ) coating, in relation to its resistance to thermal cycling fatigue. Thick TBCs, with different grade of porosity, were produced by means of a CoNiCrAlY bond coat and Yttria Partially Stabilised Zirconia top coat, both sprayed by Air Plasma Spray. The thermal fatigue resistance of new TBC systems and the evolution of the coatings before and after thermal cycling were evaluated. The limit of thermal fatigue resistance increases with amount of porosity in the top coat. Raman analysis shows that the compressive in-plane stress increases in the TBC systems after thermal cycling, nevertheless the increasing rate has a trend contrary to the porosity level of top coat.
The Growth and Influence of Thermally Grown Oxide in a Thermal Barrier Coating
Authors: Wu X.J. , Chen W.R. , Patnaik P.C.
Published: September 2022

The growth characteristics of thermally grown oxides (TGO) and their influence on microcracking in an air-plasma sprayed (APS) thermal barrier coating (TBC) were studied. The TBC samples were prepared in either as-received condition or with a pre-heat treatment. In the as-received TBC, TGO that formed upon thermal exposure predominantly consisted of layered and clustered chromia, spinels and nickel oxide, whereas in pre-heat treated samples the TGO was predominantly alumina. The growth characteristics of TGO was found to exhibit a three-stage behavior that was most pronounced in the as-received TBC. Micro-cracks were found to nucleate in clustered oxides, these cracks would grow in association with thickening of the TGO layer. Eventually, oxide-induced cracking and cracking along pre-existing discontinuities near the ceramic/bond coat interface led to spallation of the topcoat. A relationship between the maximum crack size and TGO thickness was established based on fracture mechanics considerations. This relationship is shown to be useful for TBC life prediction.
Microstructure and Thermal Cycling Behaviors of Thermal Barrier Coatings on Near-α Titanium Alloy
Authors: He B. , Li F. , Zhou H. , Dai Y. , Sun B.
Published: September 2022

Two kinds of thermal barrier coatings with NiCoCrAlY bond coatings (BCs) deposited by electron beam-physical vapor deposition (EB-PVD) and high velocity oxy-fuel thermal spraying (HVOF), respectively, as well as their top 8wt.%Y2O3-ZrO2 (YSZ) ceramic layers deposited in one batch by EB-PVD were prepared on near-α titanium alloys. The field emission scanning electronic microscopy and microhardness indentation are used in comparatively study of microstructures, microhardness of samples. Cracking modes and crack characteristics in TBCs are investigated after thermal cycling in atmosphere, along with the discussion of roles of residual stresses, bonding strengths and mechanical properties of bond coatings in different failure extents. It is found that morphologies of BCs deposited by different methods (EB-PVD and HVOF) result in the different microstructures and microhardness of their upper YSZ. The denser and more homogeneous BC prepared by EB-PVD leads to the YSZ with finer and denser columnar clusters and higher microhardness, and the inhomogeneous and porous latter results in the upper YSZ with coarser and loosely bonded columnar grains and lower microhardness, and the TBC with BC deposited by EB-PVD is more protective, which is synthetically induced by residual stresses, bonding strengths and mechanical properties of bond coatings.
Making Dense Coatings with the Solution Precursor Plasma Spray Process
Authors: Jordan E.H. , Gell M. , Bonzani P. , Chen D. , Basu S. , Cetegen B. , Wu F. , Ma X.
Published: September 2022

The Solution Precursor Plasma Spray process allows the creation of coatings directly from chemical precursors, thus avoiding the task of making sprayable powders. To date, our research has been based on injecting chemical precursors into a DC plasma torch. The process has proven to be useful in making vertically cracked thermal barrier coatings and has shown special advantages for making thick thermal barrier coatings (up to 4 mm). More recently, the process has been modified to produce dense, crack free coatings. This development was enabled by an improved understanding of the process, including making a coating almost exclusively from ultra-fine splats and avoiding the formation of vertical cracks. A crack free, dense alumina-yttria stabilized zirconia coating has been produced which is 98% dense and has an average Vickers hardness (300 gf) of 1177.
The Effect of Nanostructured YPSZ Coating Microstructure on the Thermal Conductivity
Authors: Wang Q.S. , Wang F.C. , Liu Y.B. , Ma Z.
Published: September 2022

6~8% Y2O3 partially stabilized ZrO2 (YPSZ) nanostructured coatings were fabricated by atmospheric plasma spraying (APS). The fractured cross-section morphologies of the samples were observed by scanning electron microscopy (SEM). The thermal conductivities of free-standing pure nanostructured YPSZ coatings samples were determined using the laser flash technique. Specific heat was measured through a differential scanning calorimeter. The results showed that there is a great difference between the fractured cross-section microstructure of nanostructured and conventional zirconia coatings. The nanostructured one exhibits a bimodal distribution of microstructure, viz. directional crystal and isometric crystal structure. Plasma spraying parameters have a significant effect on the microstructure through changing the content of isometric crystal structure in the coating. The thermal conductivity decreased with increased isometric crystal microstructure content. The thermal conductivity can be lowered up to 60%.
Durability of HVOF Sprayed MoB/CoCr Coating on the 316L Stainless Substrate in Molten 55%Al-Zn-1.5%Si Bath
Authors: Lv H.P. , Wang J. , Zhai C.S. , Li F. , Sun B.D.
Published: September 2022

In order to develop protective coatings for sink rolls in continuous hot-dip galvanizing, a sprayed MoB/CoCr cermet coating was formed on a 316L stainless steel by the HVOF spraying process and its durability in the molten 55%Al-Zn- 1.5%Si bath (923 k) has been investigated by SEM and EDS. The immersion test revealed that the MoB/CoCr coating has much higher durability (640 hours) in 55%Al-Zn-1.5%Si bath than the conventional sprayed coatings (120 hours), such as WC-Co, WC/Co/Cr and ceramics. It was found that the failure of MoB/CoCr coating is mainly caused by the mismatch of coefficient of thermal expansion (CTE) between the top coating and the substrate. The failure procedure is that first crack is generated because of heat stress, then the crack proceeds and causes scaled delamination, at the same time molten Al-Zn will enter into cracks and/or Al-Zn reaches the undercoat and/or substrate, finally molten Al-Zn dissolves the substrate.
Thermal Shock Behavior of the Supersonic Plasma Sprayed CeO2-Y2O3-ZrO2 Functionally Graded TBC
Authors: Han Z.H. , Wang H.J. , Guo Y.B.
Published: September 2022

A functionally graded thermal barrier coating (FG-TBC) of CeO2-Y2O3-ZrO2/NiCoCrAlY was prepared using a recently developed supersonic plasma spray (S-PS) system. The system had dual powder feed ports through which the metal alloy powders were fed into the lower temperature region of the plasma plume, to prevent over oxidation, and the ceramic powders were fed into the high temperature region, to produce complete melting. Such an approach enabled fine configurations having a continuously graded composition transition to be obtained. The thermal shock testing of the deposited samples with 1mm thick FG-TBC system on Ni-based alloy substrates was performed using an in-house-designed multi-functional rotational thermal shock tester. In this tester, the heating-cooling curves and surface morphology of tested specimens can also be observed by a microscope with a CCD (charge-coupled device) camera and recorded on line by means of accessorial computer system to evaluate the thermal shock resistance of tested samples while they were heated by a high heat flux of oxygen-acetylene flame to 1200° C in a time interval of 15~20s followed by water-quenched to ambient temperature. The temperature fields and relevant thermal stresses distribution through the thickness of disk samples were calculated by means of ANSYS finite element method. The numerical approach shows that the maximal tensile stress occur at the C-YSZ top coating at the center of disc samples at the start of rapid cooling by water-quenched, where small reticulated surface cracks were observed, which then propagated perpendicularly about 350µm deep to near the interface between the pure C-YSZ coating and the FGMs layer transition between the C-YSZ and the NiCoCrAlY coatings. These vertical cracks appeared to be arrested without any delamination after 200 thermal shock cycles.
HVOF Coatings of MoB/CoCr Against Erosion by Molten Al-Zn Alloy
Authors: Mizuno H. , Tawada S. , Aoki I. , Kitamura J.
Published: September 2022

MoB/CoCr with excellent durability against molten metal has been developed to be applied to aluminum die casting parts in automobile and to hot continuous dipping rolls in Zn and Al- Zn plating lines for steel industries. Our previous study has revealed that the MoB/CoCr coating prepared by high velocity oxy-fuel (HVOF) spraying has much higher resistance against attack of the molten Al-45wt%Zn alloys compared to conventional WC/12wt%Co coating from evaluation by laboratory scaled molten metal immersion test. However, performance with no damage is only limited when applying onto the substrate with smaller thermal expansion similar to the MoB/CoCr coatings. This paper describes the solution to prepare the MoB/CoCr coating without damage onto austenitic stainless steel of AISI316L with larger thermal expansion, whose material is commonly utilized for the hot continuous dipping rolls. It has been found that use of undercoat is effective to reduce the negative influence of large difference in thermal expansion between the MoB/CoCr coating and substrate of AISI316L. Optimized thickness of topcoat and undercoat and its combination showed intrinsic performance of low reactive MoB/CoCr without any mechanical damage such as crack and/or peeling.
Resistance of HVOF Nanostructured WC-12Co Coatings to Cavitation Erosion
Authors: Ding Z. , Zhang Y. , Zhao H.
Published: September 2022

Cavitation erosion is one of the major problems of hydraulic machinery and may cause the equipment to reduce power and then to stop working. Now with the study of nanomaterials, some special properties of nanostructured coatings are recognized and HVOF nanostructured WC-12Co coating may possess far more excellent potential to protect equipment from cavitation erosion than the conventional HVOF coatings. In the present paper nanostructured and conventional coatings were deposited by HVOF. Resistance of the coatings to cavitation erosion was studied by ultrasonic vibration cavitation equipment. Cavitation pits and craters were observed by SEM and cavitation mechanisms were explored. The results showed that nanostructured coating demonstrated more excellent performance in cavitation erosion and the erosion rate is approximately one third that of conventional one. The nanostructured existence and the increase in microhardness and toughness of the coating are important factors, which influence the resistance of coatings to cavitation erosion.
Liquid Precursors Plasma Spraying of TiO2 and Ce- Doped Ba(Zr0.2Ti0.8)O3 Coatings
Authors: García E. , Zhang Z.B. , Coyle T.W. , Hao S.E. , Mu S.L.
Published: September 2022

In this work was studied the suitability of Solution/Suspension Precursors Plasma Spray (SPPS) technique to produce titanium dioxide (TiO2) and cerium doped barium zirconium titanate (Ce doped Ba(Zr0.2Ti0.8)O3 or BZT) coatings. The precursors were sol-gel solutions typically employed to produce powders of those compositions. We report on the formation of porous TiO2 coatings on stainless steel substrates. The microstructures found this coatings are characterized by features typically found in solution precursor plasma spray processes; a combination of melted and unmelted deposits and small hollow spheres. Transmission electron microscopy revealed submicron/nanocrystalline features forming those deposits. Anatase was the main crystalline phase present in the TiO2 coatings. The rutile phase was also found in the coatings. The photocatalytic activity of the coatings was measured and compared with the results obtained for commercial anatase powders dispersed in liquid. Preliminary results obtained for Ce doped Ba(Zr0.2Ti0.8) O3 coatings deposited on mild steel substrates showed microstructures and crystalline phases suitable for dielectric applications.
Fabrication of Nano-TiO2 Coating for Dye-sensitized Solar Cell by Vacuum Cold Spraying at Room Temperature
Authors: Fan S.-Q. , Li C.-J , Yang G.-J. , Zhang L.-Z. , Gao J.-C. , Xi Y.-X.
Published: September 2022

Deposition of nanocrystalline TiO2 coatings at low temperatures is becoming more attractive due to the possibility for continuous roll production of coatings for assembly lines of dye-sensitized solar cell at a low cost. In this study, porous nano-TiO2 coatings were deposited by vacuum cold spraying at room temperature on a conducting glass substrate using commercial P25 nanocrystalline TiO2 powder. The microstructure of TiO2 coatings was characterized by field emission scanning electron microscopy and N2 adsorption test. A commercial dye (N719) was adsorbed on the surface of TiO2 particles within the coating to assemble a dye-sensitized solar cell. The cell performance was evaluated employing simulated solar light at an intensity of 100 mW/cm2. The results showed that TiO2 coatings were deposited by the agglomerates of nano-TiO2 powders. The BET test of the as-sprayed TiO2 coatings yielded a porosity of 49% and an average pore size of 17 nm. The assembled solar cell yielded a short-circuit current density of 7.3 mA/cm2 and an energy conversion efficiency of 2.4%. The test result indicates that vacuum cold spraying was a promising method to deposit nanocrystalline TiO2 coating at low temperature applied to the dye-sensitized solar cell.
LPPS Thin Film: A Hybrid Coating Technology Between Thermal Spray and PVD for Functional Thin Coatings and Large Area Applications
Authors: Refke A. , Gindrat M. , von Niessen K. , Damani R.
Published: September 2022

With the new development of the LPPS Thin-Film technology (LPPS-TF), which is a special modification of conventional LPPS using reduced chamber pressures below 10 mbar, a new window has been opened to deposit uniform and dense thin layers onto large areas in short coating times. This spray process will allow the access to new market areas and will be able to bridge the gap between conventional thin film (< 1 - 10 µm) deposition using PVD/CVD processes and thick (> 50 - 200 µm) thermally sprayed layers. This paper presents the status of the LPPS-Thin Film technology as a hybrid coating process between thermal spray and vapor deposition and gives an overview of potential applications for functional thin coatings and large area coverage.
Effect of In-Flight Particle Velocity on the Performance of APS YSZ Electrolyte
Authors: Zhang C. , Li C.-J. , Li C.-X. , Gao W. , Planche M. , Liao H. , Coddet C.
Published: September 2022

In this paper, the effect of velocity on the characteristics of atmospheric plasma sprayed yttria stabilized zirconia was investigated through adjusting auxiliary helium flow. The temperature and velocity of in-flight particles were measured with DPV2000 analyzer. The results showed that helium flow significantly influenced particle velocity and less distinctly influenced particle temperature. The microstructure of the coatings was characterized by scanning electron microscopy and X-ray diffraction analyzer. The ionic conductivity of the deposits through thickness direction was measured by a potentiostat/galvanostat based on three-electrode assembly approach in a temperature range of 500-1000 °C. The specific gas permeability was estimated. The results showed that the gas permeability was improved by increasing the in-flight particle velocity. However, the in-flight particle velocity has little effect on the ionic conductivity of specimens.
Fe-base Metal Glass Coating Produced by Gas Tunnel Type Plasma Spraying
Authors: Kobayashi A. , Yano S. , Kimura H. , Inoue A.
Published: September 2022

Metal glass has excellent functions such as high toughness and corrosion resistance. Therefore it is one of the most attractive materials, and many researchers have conducted various developmental research works. However, the metal glass material is expensive and the composite material is preferred for the industrial application. Thermal spraying method is one of potential candidates to produce those metal glass composites. The gas tunnel type plasma system, which has high energy density and efficiency, is useful for smart plasma processing to obtain high quality ceramic coatings such as alumina (Al2O3) and zirconia (ZrO2) coatings. In this study, the Fe-base metal glass coatings were produced by the gas tunnel type plasma spraying, and the microstructure and mechanical property were investigated. The Fe-base metal glass coatings of 100µm in thickness were formed densely with Vickers hardness of Hv =1000 at plasma current of 300A.
Mechanical Properties of Plasma-Sprayed Hydroxyapatite Coating after Post Heat Treatment: Effect of Residual Stress
Authors: Yang Y.C. , Chang E.
Published: September 2022

Through the measurement results of the residual strains of Hydroxyapatite coatings (HACs) and the values of Young’s moduli, the initial vacuum heating treatment (<600°C) can release the compressive residual strain of HAC after plasma spraying, so enabling HACs to obtain the optimal bond strength at the heating temperature of 500~600°C. Nonetheless, the post-vacuum heating temperature higher than 600°C led to the deterioration of the bond strength of HA/Ti-substrate. With the increasing temperature, the increased compressive residual strain will weaken the interfacial adhesive force of coating to substrate, resulting in the lower bond strength with higher temperature. The results of this paper demonstrated that the proper temperature of post-vacuum heating treatment improved effectively the bonding strength between HAC and Ti-alloy substrate.
3D Visualization of Thermally Sprayed Microstructure
Authors: Ctibor P. , Hofmann P. , Chraska P. , Lechnerova R. , Benes V.
Published: September 2022

A short survey is given of various techniques of 3D visualization of voids and other structural defects that are inherently present in thermally spray structures. It is proven that the only condition for visualization is possibility to set up a distinguishable threshold based on the gray scale of the microscopical image of the structure. Segmented images are then further processed by commercial software for image analysis, animations and anaglyph files creation. Several softwares were applied and combined, such as Lucia, Voxblast, Amira and Voxler. The visualization technique was demonstrated on a ceramic plasma sprayed coating, where two kinds of voids – semi-globular pores and large interlamellar pores could be separated. Similarly, this visualization technique can be used to distinguish between pores and oxide particles in case of metallic coatings. The visualization is done in a real Cartesian space without any transformation. The results can be useful mainly for: a) teaching to get a better insight into the microstructure of thermally sprayed coatings, b) research, where in combination with mathematical quantification the visualized structure can show important distinctions between coatings sprayed by different techniques and with variety of process parameters.
Evaluation of Strain Field Around Impacted Particles by Applying Electron Moiré Method
Authors: Watanabe M. , Kishimoto S. , Shinoda K. , Kuroda S.
Published: September 2022

Recently, the thermal spray community has focused considerable attention on Cold Spray and Warm Spray techniques, in which the temperatures of sprayed particles are kept under the melting points and adhesion occurs based on the impact phenomenon between a solid particle and a substrate. The mechanisms of adhesion are still unclear but the degree of the mechanical deformation at the interface is considered to be one key factor. However, it is very difficult to directly measure the strain at the interface. Instead, in this work, the strain fields on a substrate around an impacted particle were measured by applying Electron Moiré method, and corresponded to the spray conditions by a warm spray deposition.
Impingement Resistance of HVAF WC-based Coatings
Authors: Deng C. , Zhou K. , Liu M. , Song J. , Wu C.
Published: September 2022

HVO/AF (High-Velocity-Oxygen/Air-Fuel) WC-17Co and WC-10Co4Cr coatings exhibit great potential in the replacement of electrolytic hard chrome (EHC) coating, and comprehensive properties of such coatings should be not worse than those of electrolytic hard chrome coating. The impingement-resistance of HVAF coatings sprayed on 300M ultra-high strength steel was studied in this paper. As an important property index, the fracture toughness of HVAF WC coatings was measured using micro-indentation method at the load of 9.8, 19.6, 24.5, 29.4 and 49.0N respectively. The cracks resulted from stress concentration in the micro-indentation were analyzed. The impingement-resistance for two HVAF WC coatings and EHC was evaluated according to the ASTM D3170 standard, and steel ball dropping experimentation was performed at the height of 0.61, 1.52, 1.83, 2.36 and 2.59m respectively. The cracks caused by both impingements were analyzed using SEM and optical microscopy in comparison with cracks in micro-indentation test.
Investigation of the Corrosion Behavior of HVOF-Sprayed Carbide Cermet Coatings in Molten Al-Zn-Si Alloy Bath
Authors: Tan X.H. , Jiang Z.H. , Zhang Y.G. , Sun J.S.
Published: September 2022

In the continuous hot-dip galvanization process, the corrosion and chemical stability of the sink roll in the galvanizing bath are important issues that affect quality and productivity. In order to protect the sink roll, carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3C2- cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50wt.% aluminum at 833K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in the coating and corrosion behavior of these coatings were investigated by XRD, SEM and EPMA, etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were proposed.
Erosion Properties of Plasma Sprayed Ceramic Coatings Against Process Plasma in Semiconductor Production Equipment
Authors: Kitamura J. , Ibe H. , Mizuno H. , Aoki I.
Published: September 2022

Erosion properties of high purity alumina (Al2O3) and yttria (Y2O3) coatings prepared by plasma spraying have been investigated against process plasma in semiconductor and liquid-crystal-display (LCD) production equipments for dry etching. Studies on plasma power dependency have revealed that yttria coatings have showed higher anti-plasma erosion resistance than alumina coating as well as sintered alumina bulk at every condition. Although yttria coatings are inferior to sintered yttria bulk, the difference of the resistance becomes smaller with increasing plasma power. This result positively promotes the application of the yttria spray coating because of increasing plasma power in actual process. Erosion properties of the coatings against Ar/CF4/O2 plasma, whose composition is increasingly being used in commercial process, are also investigated where physical etching effect becomes stronger than the typical CF4/O2 case. It has been found that order of durability (yttria bulk > yttria coatings > alumina bulk > alumina coating) is independent of the gas species used in this study. The mechanism of the plasma erosion is discussed through micro-structural analysis of the eroded surfaces.
Microstructure and Properties of Silicon Coating Prepared by Air Plasma Spraying
Authors: Niu Y.R. , Liu X.Y. , Zhou X.M. , Ding C.X.
Published: September 2022

In the present work, silicon coating was deposited using air plasma spraying technology. The temperature and velocity of particles in the plasma spraying were measured. The phase composition and microstructure of the coating was studied. And some mechanical and thermal properties of the coating were evaluated.
Influence of Particle Size on Microstructure and Properties of Al2O3 Coatings Deposited by Plasma Spraying
Authors: Yin Z.J. , Tao S.Y. , Zhou X.M. , Ding C.X.
Published: September 2022

In the present study, Al2O3 coatings were deposited by plasma spraying using feedstock of different particle sizes. The effects of particle size on their velocity and temperature in the plasma jet, the microstructure and properties of the coatings were investigated. The results revealed that in view of the smaller inertia effects and lower heat capacity, the smaller particles can be easily accelerated and heated, and have higher in-flight velocity and temperature, which contributed to produce a denser coating with lower porosity and higher mechanical properties. It was also found that the coating deposited using the finest starting powder has the lowest thermal diffusivity. This may be reasonably correlated with the microstructural characteristics. In addition, the coating manufactured using the intermediate feedstock in terms of particle size (D50 of 19.3µm) exhibited the highest wear resistance.
Properties of Copper Coatings Deposited by Multi-function Micro-plasma Spraying
Authors: Liu G. , Wang L.Y. , Wang H.G. , Hua S.C.
Published: September 2022

In this paper, copper coatings were deposited on a metallic substrate by means of multi-function micro-plasma spraying under different processing parameters. The microstructure and phase structure of copper coatings were investigated using a scanning electron microscope and X-ray diffraction, bonding strength were tested by an electron tensile tester, droplet impinging and flattening on a flat substrate surface and the residual stress after solidification were studied numerically. The experimental results show that the density of copper coatings was improved with increasing plasma power and operating gas flow, and this copper coating possessed high adhesion strength and low residual stress, still without obvious oxidation. This spraying system extends the application field of tradition plasma spray. Through changing the processing parameters, materials with different melting points, even as low as copper can be produced.
Effects of Laser Irradiation on Plasma Sprayed AI2O3 Coatings
Authors: Kobayashi Y. , Ohmura E. , Ueki S.
Published: September 2022

In order to clarify the effects of two kinds of laser irradiation on plasma sprayed alumina coatings, microstructure, crystallization and mechanical properties of the spacemen were examined and heat conduction in the laser irradiation processes were analyzed by a finite element method. One is CW CO2 laser irradiation of low power density, and the other is pulse excimer laser irradiation of high intensity but low energy density. Al2O3 coatings were irradiated by CO2 laser with low intensity, fine structure formation composed of α- Al2O3 was confirmed and the surface roughness was improved although the hardness decreased a little. The modified layer was corresponding to the area that was heated above 1000 to 1100°C in the calculated maximum temperature distribution. It was also confirmed that the excimer laser pulse has a potential to improve the properties of surface layer to a depth of several micrometers.
Effect of the Blasting Angle on the Amount of the Residual Grit on Blasted Substrates
Authors: Maruyama T. , Akagi K. , Kobayashi T.
Published: September 2022

The residual grit weight and the penetration depth of the embedded grit were investigated by dissolution of the blasted substrate with a mixed acid solution. A carbon steel substrate was blasted by white alumina grit (WA #30). The blasting angle varied from 30° to 90°. The residual grit amount and the penetration depth increased with increasing blasting angle. The residual grit amount was 2-12 g/m2, and the penetration depth was 26-34 µm. When the blasting angle increased from 30° to 90°, the increase ratio of the residual grit amount was 6.0, although the increase ratio of perpendicular component of impact energy by blasting was 2.0. To reduce the residual grit amount, a decrease of blasting angle is more effective than the decrease of grit mass. For the reduction of the penetration depth of the embedded grit, the blasting angle effect is small.
Microstructure and Electrical Conductivity of Atmospheric Plasma Sprayed LSM-YSZ Composite Cathode Coating
Authors: Zhang C. , Li W.-Y. , Liao H. , Coddet C. , Li C.-J. , Li C.-X.
Published: September 2022

Yttria stabilized zirconia and lanthanum strontium manganate (YSZ/LSM) have been employed to fabricate the composite cathode functional layer for solid oxide fuel cells (SOFCs). In the present study, the YSZ/LSM composite coating was deposited by atmospheric plasma spray (APS). The electrical conductivity of the composite coating was measured by the means of Direct Current (DC) measurement in a temperature range of 500-900 °C. The electrical conductivity of YSZ- 50%LSM coating changed from 2.17 S/cm to 3.60 S/cm along the direction parallel to the coating surface at the temperature range. For the same specimen, the electrical conductivity in the perpendicular direction is less than one-tenth of that in the parallel direction. The anisotropy of the electrical conductivity is attributed to the phases of different properties in the composite coating and the APS coating structure characteristics. The activation energy of the composite coating at both directions was calculated. The results showed that the electrical conduction of the composite was strongly influenced by the YSZ content.
Study on Abrasive Resistance of Arc Spraying Fe-Based Coatings Containing Cr3C2 Hard Phase
Authors: He D.-Y. , Fu B.-Y. , Jiang J.-M. , Li X.-Y.
Published: September 2022

Thermal spray processes are widely used to protect materials and components against wear, corrosion and oxidation. As commercial arc sprayed coatings have been used to a limited extent in applications involving erosion and abrasion wear, developing attractive wear resistance arc sprayed coatings has been found necessary. Abrasive wear testing was carried out on four Fe-based composite coatings containing varied contents of Cr3C2 particles as hard phases. Scanning electron microscopy (SEM) was used for observing the surfaces of the composite coatings, and wear mechanisms of the coatings were discussed on the basis of the observation. The results obtained from MLS- 225 wet sand/rubber wheel test showed that the abrasive wear resistance of composite coatings with Cr3C2 hard phase is about 28 times higher than that of Q235 mild steel. The coating method was proved effective in producing a uniform and dense lamellar structure. The excellent abrasive resistance of the composite coatings with Cr3C2 particles were found to be related to three major factors: enhanced bulk hardness, compact lamellar structure and strong bonding between matrix and hard phase, as well as a load supporting system constructed by the hard phase structure.
Possibilities for Qualification and Certification of Personnel, Companies and QM-Systems in the Field of Thermal Spraying
Authors: Böhme D. , Huber R.
Published: September 2022

In the thermal spraying technology a lot of things have been and still are happening in education and training of personnel and in quality management. The QM-system that was established by the GTS e.V.– the Association of Thermal Sprayers – was pioneer and does an excellent job concerning its requirements. These GTS QM-requirements are meanwhile completed by newly created and internationally accepted EWF-education and training guidelines of supervising personnel and thermal spray workers. These guidelines involve also the new ISO standards of the Thermal Spraying Coordinator and the Approval Testing of Thermal Sprayers. Meanwhile the ETS (European Thermal Sprayer) and the ETSS (European Thermal Spraying Specialist) education and training courses are very much in demand. For the QM-System the standard ISO 14922 Part 2-4 (Quality requirements of thermally sprayed structures) is established, which includes the standard ISO 14918 (Approval Testing of Thermal Sprayers). Here, different destructive testing procedures are required depending on the spray process, which provide useful statements concerning the quality of sprayed coatings. With the GTS-Certification, the EWF-Qualifications and the ISO Standards a System is installed, which meets the increased Demands of Trade and Industry for High Quality Sprayed Coatings.
Workpiece Related Quality Management on High-End Thermal Spray Systems
Authors: Kilchenmann A. , Haas M.
Published: September 2022

In the thermal spray business quality assurance reports from a high end system usually contain only the values of the thermal spray process. But what about handling system values like spray distance and surface velocity. The paper shows the possibilities that are available today on a MultiCoat Vision thermal spray installation and focuses on a quality assurance report that includes the values of the entire system, as well as, the details from the sprayed workpiece.
ФОРМУВАННЯ ІНФОРМАЦІЙНОЇ КОМПЕТЕНТНОСТІ ЗДОБУВАЧІВ ВИЩОЇ ОСВІТИ В ПРОЦЕСІ ПРОФЕСІЙНОЇ ПІДГОТОВКИ
Authors: Плужник Оксана
Published: September 2022

У статті досліджено сутність поняття «інформаційна компетентність» та його місце у процесі професійної підготовки майбутніх фахівців за спеціальностями 015 «Професійна освіта», 029 «Інформаційна, бібліотечна та архівна справа». Проаналізувавши праці вітчизняних та зарубіжних науковців, зʼясовано, що під інформаційною компетентністю розуміють сукупність компетенцій, які дозволяють ефективно користуватись інформаційними технологіями у роботі з інформацією як у друкованій формі, так і в електронній.
Підкреслено, що важливим чинником формування інформаційно-комунікативної компетентності та забезпечення успішності професійної діяльності майбутнього фахівця є сформована інформаційна культура особистості, яка включає культуру знання оптимальних способів поведінки зі знаками, даними, інформацією, знання механізмів вдосконалення технічних засобів виробництва, зберігання й передачі інформації, вміння працювати з нею та поширювати.
Досліджено компоненти інформаційної компетентності з точки зору американських науковців та вітчизняних. В ході дослідження з’ясовано, що вони в цілому мають спільні характеристики. Так американські вчені вбачають складовими інформаційної компетентності: інструментальну, ресурсну, соціально-структурну, дослідницьку та публікаційну грамотність. Вітчизняними науковцями виокремлюються такі складові: інформаційна, комп’ютерно-технологічна та процесуально-діяльнісна компонента. 
Проаналізовано Стандарти вищої освіти України за спеціальностями 015 «Професійна освіта» та 029 «Інформаційна, бібліотечна та архівна справа» першого (бакалаврського) рівня та визначено їх особливості.
З’ясовано, що в процесі професійної підготовки майбутніх фахівців важливе місце займає блок комп’ютерних дисциплін та дисциплін інформаційно-комунікативного циклу. Також доцільно використовувати в освітньому процесі професійно орієнтовані завдання, в ході виконання яких студент не тільки оволодіває новими вміннями і навичками з дисципліни, а й набуває професійних компетенцій, необхідних в подальшій професійній діяльності.
ДЕРЖАВНЕ БУДІВНИЦТВО НЕЗАЛЕЖНОЇ УКРАЇНИ КРІЗЬ ПРИЗМУ НОРМАТИВНО-ПРАВОВИХ АКТІВ: 30 РОКІВ ДОСВІДУ
Authors: Коцур Леся
Published: September 2022

У статті проаналізовано процес державотворення незалежної України крізь призму нормативно-правових документів прийнятих упродовж останніх тридцяти років. Розкрито особливості прийняття актів, які прискорили процес унезалежнення України від СРСР та сформували кістяк майбутньої державності; документів прийнятих у перші роки розбудови молодої держави, які ухвалювалися в процесі гострих суперечностей між різними гілками влади, зокрема Президентом і Верховною Радою України; нормативно-правових актів кінця 1990-х – перших десятиліть 2000-х рр., які чітко розкривають вплив фінансових, геополітичних та цивілізаційних чинників на прийняття відповідних документів. Окрему увагу приділено ролі Конституції України у процесі будівництва держави та іншим нормативним актам покликаним зміцнити самобутність українського народу, вирвавши її ідентичність з ідеологічних лещат Кремля. Показано, що попри наявну широку нормативну базу, багато документів носили суто декларативний характер, що мало вкрай негативні наслідки під кутом зору майбутніх державотворчих перспектив