bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the Influence of Flame Spraying Parameters on Microstructure and Electrical Conductivity of Al-12Si Coatings Deposited on Polyurethane Substrates
Authors: Ashrafizadeh H. , Mertiny P. , McDonald A. 
Published: August 2022

Abstract
The influence of flame spraying parameters on coating microstructure and electrical conductivity of aluminum- 12silicon coatings deposited on polyurethane substrates was studied. In order to evaluate the effect of the spray parameters on temperature distribution and its corresponding effect on coating characteristics, an analytical model based on a Green’s function approach was employed. It was found that the addition of air to the flame decreased the temperature within the substrate. Dynamic mechanical analysis (DMA) of the PU substrate revealed that the PU softened as the temperature increased. Therefore, by increasing the pressure of the air injected into the flame spray torch from 35 kPa to 69 kPa, the particles impacted a stiffer substrate. This led to increased deformation of the particles into splats upon impact, improved interlocking, and the overall coating had lower porosity and lower electrical resistance. The results obtained indicated that coating properties are sensitive to both thermal spraying parameters and temperature distribution within the substrate when depositing on elastomeric materials. The effect of torch stand-off distance on coating properties was also evaluated. It was found that higher air pressure can cool the substrate and, therefore, allow for a decrease of the stand-off distance. As a result of shorter stand-off distances, a coating with lower porosity and electrical resistance was deposited.
Evolution of Microstructure and Wear Behavior of Heat-Treated and Fused Arc-Sprayed Coatings Containing Fe2B Crystals Dispersed in Different Steel-Based Matrices
Authors: Dallaire S. 
Published: August 2022

Abstract
Thermally sprayed coatings are mechanically bonded to the substrate and present porosities and a lamellar microstructure that make them less attractive in applications requiring high coating toughness and impermeability to gas and liquids, these properties been obtained with more technically advanced overlaying processes. This paper presents the research work carried out to increase the erosion resistance of arc-sprayed coatings containing hard Fe2B crystals dispersed in mild and alloyed steel-based matrices. These arc-sprayed coatings were a) heat-treated in furnace up to 1000°C and b) fused with an oxy-acetylene torch. The sprayed specimens were tested in a particle erosion device at the impact angles of 25° and 90°. The evolution of microstructure was done by SEM and wear damage by Time- Domain Optical Coherence Tomography. It was shown that both the heat treatment and fusing processes considerably enhanced the erosion resistance of coatings particularly at the impact angle of 90°. This increase in erosion resistance is attributed to the disappearance of stringers between sprayed lamellae. Liquid phase sintering is the mechanism responsible for the homogenization of arc-sprayed coatings containing Fe2B. Grain growth observed in arc-sprayed coatings heat-treated up to 1000°C or fused with an oxyacetylene torch does not have a detrimental effect on erosion resistance.
Fatigue Performance of TBCs on Hastelloy X Substrate during Cyclic Bending
Authors: Musalek Radek , Medricky Jan , Pala Zdenek , Kovarik Ondrej , Tomek Libor , Curry Nicholas , Bjorklund Stefan 
Published: August 2022

Abstract
Our previous experiments with low-cost steel substrates confirmed that individual steps of conventional thermal barrier coating (TBC) deposition may influence fatigue properties of the coated samples differently. In this study, testing was carried out for TBC samples deposited on industrially more relevant Hastelloy X substrates. Samples were tested after each step of TBC deposition process: as-received (non-coated), grit-blasted, bond-coated (NiCoCrAlY) and bondcoated + top-coated (yttria-stabilized zirconia - YSZ). Conventional atmospheric plasma spraying (APS) with gas stabilized plasma torch was used for deposition of both bond coat and top coat. In addition, for one half of the samples, bond coat was prepared by consecutive combination of HVAF (High Velocity Air Fuel) and APS processes. Samples were tested both in as-sprayed condition and after 100 hours annealing at 980 °C, which simulated in-service conditions. Obtained results showed that different fatigue performance may be expected for various stages of the TBC deposition as well as due to the variation of the deposition process and sample temperature history.
Fracture Behavior and Lifetime Performance of Thermal Barrier Coatings in Thermally Graded Mechanical Fatigue Environments
Authors: Lu Zhe , Myoung Sang-Won , Jung Yeon-Gil , Zhang Jing , Paik Ungyu 
Published: August 2022

Abstract
The effects of bond coat species on the fracture behavior and lifetime performance were investigated in thermal barrier coating (TBC) systems through thermally graded mechanical fatigue (TGMF) tests. Two types of process, air-plasma spray (APS) and high-velocity oxygen fuel (HVOF), were employed to prepare the bond coats of about 300 μm thickness, and then the top coat of about 600 μm thickness was coated on the both bond coats by APS process. The TGMF tests with two tensile loads of 100 and 150 MPa were performed until 900 cycles at a surface temperature of 850 and 1100 °C for a dwell time of 10 min, and then the sample was cooled at the room temperature for 10 min at each cycle. When the tensile load applied in TGMF tests was 100 MPa at 850 °C, the TBC with APS bond coat showed delamination phenomena at the interface between the top and bond coats and small cracks on the surface after about 250 cycles, while the TBC with HVOF bond coat showed a long crack at interface between the top and bond coats without delamination phenomena until 900 cycles. As the tensile load in TGMF tests was increased to 150 MPa at 850 °C, delamination and/or cracks were created at the relatively low cycles, after about 130 and about 279 cycles for the TBCs of the APS and HVOF bond coats, respectively. When the tensile load applied in TGMF tests was 100 MPa and the temperature increase to 1100 °C, the TBC with APS and HVOD bond coats were delaminated after about 65 and about 110 cycles, respectively. These evidences indicate that the TBC with HVOF bond coat is more efficient in improving lifetime performance than that with APS bond coat in the thermal and mechanical environments.
Influence of Grit Blasting on the Interface Roughness and Adhesion Strength of Cold Sprayed Copper Coatings
Authors: Maev R.Gr. , Leshchynsky V. , Strumban E. , Dzhurinskiy D. , Maeva E. 
Published: August 2022

Abstract
Surface preparation is very important for reliable adhesive bonding of cold sprayed coatings to the substrate. In this work, the grit blasting of low-carbon A516 steel substrates with Al2O3 particles was studied and the roughness parameters Ra and Rt of the grit blasted surfaces were then measured. The influence of alumina grit size on the roughening of the A516 steel substrate, and the resulting effect on the roughness of the Cu coating – steel interface were studied. The results showed that variations of the grit blast size had significantly affected the resultant surface roughness of the substrate. The adhesive strength of the formed copper coatings on A516 steel substrates depends on the surface roughness and hardness of the base material. The adhesive strength about 110-200MPa was achieved. The specific features of the Cu coating-A516 steel interface topography were examined and discussed.
Influence of Microstructure on Thermal Properties of Columnar Axial Suspension Plasma Sprayed Thermal Barrier Coatings
Authors: Ganvir Ashish , Curry Nicholas , Markocsan Nicolaie , Nylen Per , Vilemova Monika , Pala Zdenek 
Published: August 2022

Abstract
Suspension Plasma Spraying is a relatively new thermal spaying technique to produce advanced thermal barrier coatings. This technique enables the production of a variety of structures from highly dense, highly porous, segmented or columnar coatings. In this work a comparative study is performed on six different suspension plasma sprayed thermal barrier coatings which were produced using axial injection and different process parameters. The influence of coating morphology and porosity on thermal properties was of specific interest. Tests carried out include microstructural analysis with SEM, phase analysis using XRD, porosity calculation using Archimedes experimental setup, pore distribution analysis using mercury infiltration technique and thermal diffusivity/conductivity measurements using laser flash analysis. The results showed that columnar and cauliflower type coatings were produced by axial suspension plasma spraying process. Better performance coatings were produced with relatively higher overall energy input given during spraying. Coatings with higher energy input, lower thickness and wider range of submicron and nanometer sized pores distribution showed lower thermal diffusivity and hence lower thermal conductivity. Also, in-situ heat treatment did not show dramatic increase in thermal properties.
Influence of the Plasma Radiation Scattered by Inflight Particles on Temperature Measurement in Suspension Plasma Spraying
Authors: Aziz Bishoy , Moreau Christian 
Published: August 2022

Abstract
The temperature of in-flight particles in plasma spraying is one of the main parameters affecting the coating microstructure. Temperature measurement has been carried out before for inflight particles in air plasma spray (APS) and other thermal spraying processes. Suspension plasma spray (SPS) is an emerging coating deposition technology that permits the deposition of nanostructured coatings with unique structural characteristics. The aim of this work is to evaluate the influence of radiation emitted by the plasma and metallic vapors on temperature measurement of SPS particles performed by two-color pyrometry. To do so, spectroscopic analysis in the visible to near-infrared range is carried out on the jet stream when suspension of 20wt% YSZ particles in ethanol is sprayed. The analysis takes into account the radiation scattered by the particles (Mie scattering) as well as the radiation directly detected from the jet stream, and it was found that the effect of the scattered radiation by the particles on temperature measurement is 1 degree at its melting point (2700°C) and 16 degrees at 2500°C.
Investigation of Alumina and Yttria Coating Microstructures Manufactured by Suspension Plasma Spray
Authors: Aubignat E. , Planche M.-P. , Montavon G. , Allimant A. , Billieres D. 
Published: August 2022

Abstract
Alumina and yttria coatings, manufactured by suspension plasma spraying, were investigated to understand the “material effect” in the coating building. Some particle image velocimetry measurements were carried out to evaluate the particle velocities into the plasma. Some particle collections were performed to get information on their molten state. Splats were observed by scanning electron microscopy (SEM) and their dimensions were measured with an interferometric profilometer. Coating cross sections were finally observed by SEM and porosity rates were evaluated by image analysis and ultra-small angle X-scattering. This study revealed no real difference between the two materials concerning particle velocity. However, splat analyses highlighted a better flattening ratio for yttria particles, due to a lower difficulty to melt of this material. This property seems to enhance particle vaporization whose condensates are found on coating surface. These observations explain the difference of pore size distributions observed for both coatings.
Investigation of the Interface of Overlapping Splats for a WC-Based Cermet
Authors: Hussong B. , Lünnemann V. , Tillmann W. 
Published: August 2022

Abstract
In this investigation, the behavior of overlapping HVOF-sprayed WC-Co splats is analyzed. Samples are sprayed and documented in several steps with a low density of splats. This method enables to distinguish between several splats in areas where overlapping clusters of splats occur. The splats are sorted according to their chronological order of impact. With this information, cross sections are made of these clusters to study the porous structure, developing in the center and at the boundaries of the splats. An ion-polishing method was employed to avoid the corruption of small pores and structures by mechanical force. It turns out that pores in HVOF coatings are initiated by the overlapping regions at the edges of the splats. Splats impacting directly onto each other show very dense microstructures at the interface in the center region of the impact.
Joining of Dissimilar Materials by the Cold Spray Process
Authors: Champagne Victor Kenneth , West Michael K. , Reza Rokni M. , Curtis Todd 
Published: August 2022

Abstract
This paper presents a concept to develop a practical method to join dissimilar materials by the cold spray process currently not possible with conventional technologies. The novel aspect of the process includes the development of a joint design using cold spray as the enabling technology to join dissimilar materials. The emphasis in this study will be on the method used in the joining of cast ZE41A-T5 magnesium and wrought 6061 aluminum by the cold spray process (CSP) in combination with friction-stir welding (FSW) and the subsequent materials characterization. Microstructural analysis by electron and optical microscopy, along with mechanical test results will be presented. Comparisons will be made to conventional joining techniques and the importance, as well as the applications of this technique, will be discussed.
Low Cost Suspension Plasma Spraying of YSZ Coatings
Authors: Shahien Mohammed , Suzuki Masato 
Published: August 2022

Abstract
Suspension plasma spraying (SPS) process is showing promising improvements for the Thermal barrier coatings (TBCs) performance. This study will focus on the development of a low cost suspension plasma spray system with an axial feeding of yttria stabilized zirconia (YSZ) coatings. A unique twin-cathode plasma spray gun with three plasma torches; P-torch (reversed polarity: cathode nozzle and anode), and two N-torches (normal polarity: anode nozzle and cathode) was used. During operation, the electric power is supplied between P-torch anode and N-torches cathodes to maintain the plasma jet. The system requires only argon as plasma gas, since the enthalpy of plasma jet is enough high for melting ceramic powders, which makes it as cost reduction system. Moreover, the p-torch electrode is hollowed anode and therefore commercial dual tube nozzle was used for the axial feeding to increase the deposition efficiency. It was possible to fabricate dense and/or porous 8YSZ coatings with using only Ar plasma gas through using the twin cathode plasma spray system and the axial injection. The coating microstructure and porosity level can be controlled by appropriate changes in the solids amount in the suspension and the spraying parameters. To control the microstructure the main factor is controlling and adjusting the splat size.
Mechanistic Study and Characterization of Cold Sprayed Ultra-High Molecular Weight Polyethylene-Nano Ceramic Composite Coating
Authors: Ravi Kesavan , Ichikawa Yuji , Ogawa Kazuhiro , Deplanke Tiana , Lame Olivier , Cavaille Jean-Yves 
Published: August 2022

Abstract
The cold spray deposition of ultra high molecular weight polyethylene (UHMWPE) powder mixed with nano alumina, fumed nano alumina and fumed nano silica was attempted on two different substrates namely polypropylene (PP) and aluminum (Al). Approximately 4mm and 1mm thick coating were observed on Al and PP substrates respectively with UHMWPE and fumed nano alumina mixture. The nano ceramic particles played an important role as a bridge bond between the particles. The coatings with nano alumina, fumed nano alumina and fumed nano silica were very contrasting in terms of coating thickness. Gas temperature and pressure played an important role in the deposition. The differential scanning calorimetry (DSC) results of the coatings showed that UHMWPE was melt crystallized after the coating. The substrate properties also affected the deposition mechanism greatly.
Modeling of the Self-Assembly of Nanoparticles into Branched Solid Aggregates for a Suspension Droplet
Authors: Zhang He , Shan Yanguang 
Published: August 2022

Abstract
In the suspension plasma spray, nanosized particles are suspended in a liquid and the suspension is injected into the plasma to deposit coatings. The structure of the highly branched solid aggregates has significant influence on the microstructure and performance of the coating. In this paper, we investigate the formation of branched nanoparticle aggregates resulting from the evaporation of nanofluid droplets. A kinetic Monte Carlo (KMC) approach is used to simulate the drying process of a nanofluid droplet in a circular domain. It is found that the two-dimensional lattice-gas-based Monte Carlo model can describe the self-assembly of nanoparticles into a highly branched solid aggregate. The results reveal that the fingering contact line instabilities can emerge under a given condition and force the formation of a branched nanoparticle structure. The results also show that the initial chemical potential of boundary and the rate of chemical potential change have significant influence on the resulting patterns and the finger number.
Preparation and Characterization of Transparent Hydrophobic Al2O3 Surface by Vacuum Cold Spray
Authors: Li J. , Zhang Y. , Li C.-X. , Pan X.-D. , Yang G.-J. , Li C.-J. 
Published: August 2022

Abstract
Transparent hydrophobic materials have broad application prospects in industry and daily life due to its transparent and super-hydrophobic characteristics, while its performance will be significantly influenced by the materials and its surface morphology. Hydrophobicity and transparency are competitive properties from the viewpoint of surface roughness. However, there are still a lot of problems to be solved to satisfy hydrophobicity and transparency simultaneously in the prepared surface. A novel and simple method to fabricate transparent hydrophobic surface is introduced in the present paper. Micron and sub-micron mixed Al2O3 powders were deposited on the glass and plastic substrate by vacuum cold spray. The coatings were modified by 1,1,2,2- Tetrahydroperfluorodecyltrimethoxysilane (FAS) to reduce the surface energy. The surface morphology was characterized by scanning electron microscopy (SEM) and 3D laser microscopy (LSM). The transmittance of the coating was also investigated. The results show that the as-sprayed surfaces exhibit submicron structure. After FAS absorbing treatment, the contact angle of water droplets on the coatings ranged from 108° to 136° depending on the local surface morphology, and the transmittance of Al2O3 coatings are all above 80% in the range of visible light.
Stress Formation within the First Layer in Plasma Sprayed Coatings
Authors: Mutter Markus , Mauer Georg , Mücke Robert , Vaßen Robert , Back Hyoung Chul , Gibmeier Jens 
Published: August 2022

Abstract
The residual stresses within plasma sprayed coatings are an important factor which can influence the lifetime of the coatings. The investigation of the evolving stresses during deposition and post-deposition cooling of YSZ coatings by measuring in-situ the specimen’s curvature with the so-called ICP sensor is a powerful tool to identify the different stress generation factors. Under certain spray conditions one can observe that the first torch pass leads to a significantly higher increase in specimen´s curvature than the following deposition passes, which indicates significantly higher stresses within the interface coating region. The reason for this steep curvature increase was investigated. It is suggested to be a combination of a stronger bonding of those splats being connected directly to the substrate and the relief of compressive stress within the substrate. The slope of this increase depends on the spray parameters as well as on the substrate conditions, which was investigated also.
Taguchi Design and Analysis of 3D-Computer Fluid Dynamic (CFD) Experiments (TDACE) for the Optimization of Air-Cap Configuration in Arc Spraying
Authors: Tillmann W. , Abdulgader M. , Anjami N. , Bezerra D. 
Published: August 2022

Abstract
The computational fluid dynamic approach is adopted in this work, using L16-Taguchi matrix, to study the effect of different secondary atomization gas outlet configurations on the gas velocity, jet divergence, and pressure distribution at cap outlet. The spraying process variables that are integrated in this study are primary and secondary atomization gas pressure, PG and SG respectively. In addition, the geometrical variables of the SG air-cap like the position, the number and the angle of the outlet holes for SG are a part of the L16-Taguchi matrix. The effect of the process variables and geometrical design variations are analyzed on the obtained gas flow characteristics. Increasing the number of the SG outlet holes leads to a higher gas velocity at the cap outlet. The amount and the angle of the SG outlet holes have a direct effect on the plume divergence. The SG outlet angle determines the distance between the flow intersection point (PG-flow and SG-flow) and the air-cap outlet. Increasing the SG outlet angle leads to a reduction of the gas velocity. The use of Design of Experiment (DoE) in the optimization of the air-cap design by implementing CFD-simulation was proved to be a very useful and efficient tool to design high performance air-caps of twin-wire arc-spraying.
The Many Facets and Complexities of 316L and the Effect on Properties
Authors: Miller Ingrid Hauer 
Published: August 2022

Abstract
One of the most widely accepted and versatile materials used with many coating deposition methods is austenitic stainless steel 316L. This is due to the combination of good corrosion and mechanical properties that are suitable for numerous varying applications. As a result of our familiarity with 316L we assume the properties achieved will be within the expected frame as described in the literature. Deposition techniques and component size and shape have an impact on the heating and cooling variations which will then affect the microstructure of the final coating. This in turn will result in variations in the properties achieved. Some of these numerous factors such as: deposition technique, component geometry and size, impurities in the substrate and chemistry of the substrate will be considered. The influence of these factors on the microstructure and the definitive properties of 316L will be presented.
The Shear Test According to DIN EN 15.340—Advantages, Disadvantages, Improvements, and Important Directions
Authors: Hartmann S. 
Published: August 2022

Abstract
The shear test developed within a European research project has important advantages compared to the coating strength test mainly in use today, the adhesion strength test according to DIN EN 582 or ASTM C 633. One of the main advantages is that no glue is used avoiding any possible influences of the glue. Furthermore the test is a rapid process compared to the adhesion strength test as there is no gluing procedure. However a number of very important directions have to be obeyed in order to make sure that the shear test is correct and comparable results can be reached. This is very important as in many cases it is not possible to control after the test if the directions had not been correctly obeyed. A number of further rules need to be followed to make sure the test results are correct. Within this presentation these direction will be summarized and essential hints will be given to make sure the test is carried out in the correct way. Finally a comparison will be given between the tensile adhesive test and the shear test from the practical and economical point of view of obz innovation gmbh, a thermal and cold spray job shop.