bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal-Glass Composites for Application in TBC Systems
Authors: Mack D.E. , Gross S.-M. , Vaßen R. , Stöver D. 
Published: September 2022

Abstract
A new type of thermal barrier coating (TBC) based on metal-glass composite (MGC) has been recently presented. Beside the availability of conventional manufacturing routes of the coating, e.g. by vacuum plasma spraying (VPS) or slip casting, there are two main advantages of the new TBC: The thermal expansion coefficient can be easily adjusted to the substrate by changing the metal to glass ratio of the composite and the severe oxidation of the bondcoat layer can be reduced due to the gastightness of the glassy phase. Nevertheless, oxidation of the metal phases cannot be fully suppressed up to now. Concepts for a multilayer system and an improved oxidation resistance of a MGC based on suitable heat treatments and on alternative glass compositions have been developed. Results from isothermal oxidation experiments and from thermal cycling in burner rig facilities will be discussed.
Process Residual Stresses and High Temperature Oxidation Performance of Thermal Barrier Coatings
Authors: Lima C. R. C. , Nin J. , Guilemany J.M. 
Published: September 2022

Abstract
Thermal barrier coatings (TBCs) allow increasing combustion temperatures of gas turbines and diesel engines thus improving the system performance. Residual stresses due to the differences of thermal expansion coefficient between metallic bond coat and ceramic top coat as well as the stresses due to the oxidation of the bond coat and the consequent increase in the thermally grown oxide (TGO) layer lead to ceramic debonding and subsequent failure of the thermal barrier system in service conditions. Extensive research has been carried out to minimize such events by applying multilayered coatings, intermediate diffusion or protective layers and other methods. In this work the TBC systems were obtained by applying distinct bond coats and top coats. The bond coats were applied by High Velocity Oxygen Fuel (HVOF) and the ceramic top coats were applied by Air Plasma Spraying (APS). Residual stresses were measured by the Modified Layer Removal Method (MLRM). Isothermal high temperature oxidation tests were performed and the results were correlated with the post spraying stress state and the coating thermal history. Results show that the residual stresses are mainly influenced by the thermal history regarding the quenching of individual splats and the plastic deformation of ceramic deposits.
Effect of Particle Impact on Residual Stress Development In HVOF Sprayed Coatings
Authors: Bansal P. , Shipway P.H. , Leen S.B. 
Published: September 2022

Abstract
The application of thick HVOF coatings on metallic parts has been widely accepted as a solution to improve their wear properties. The adherence of these coatings to the substrate is strongly influenced by the residual stresses generated during the coating deposition process. In an HVOF spraying process, due to the relatively low processing temperature, significant peening stresses are generated during impact of semi-molten particles on the substrate. At present, FE models of residual stress generation for the HVOF process are not available due to the increased complexities in modelling the stresses generated due to the particle impact. In this work, deposition of an HVOF sprayed copper coating on a copper substrate is considered as an example system. An explicit finite element analysis is carried out to study the effect of particle impingement. The results from the analysis are subsequently used in a thermo- mechanical FE model to allow the development of the residual stresses in these coatings to be modelled.
The Effect of the Substrate Hardness on Particle Morphology in High Velocity Thermal Spray Coatings
Authors: Neufuss W. , Dyshlovenko Trompetter , Markwitz A. , Hyland M. , McGrouther D. , Munroe P. 
Published: September 2022

Abstract
In this study, Ni-chrome alloy particles were thermally sprayed onto a variety of substrate materials using the high velocity air fuel (HVAF) technique. Although the various substrate materials were sprayed using identical powder material and thermal spray conditions, the type and variation of splat morphologies was strongly dependent on the substrate material. Predominantly solid particles are observed penetrating deeply into softer substrates, such as aluminium, whereas molten splats were observed in harder substrates, which resisted particle penetration. While the observed correlation between molten splats and substrate hardness could be due a dependency of deposition efficiencies of solid particles and molten splats on the substrate material, it was found that conversion of particle kinetic energy into plastic deformation and heat, dependent on substrate hardness, can make a significant contribution towards explaining the observed behaviour.
Relationship Between the Suspension Properties and Liquid Plasma Sprayed Coating Characteristics
Authors: Toma F.L. , Bertrand G. , Rampon R. , Klein D. , Coddet C. 
Published: September 2022

Abstract
The suspension plasma spraying using a liquid as material feedstock is a promising technique to elaborate thin and nanostructured coatings. This work deals with the study of suspensions in order to obtain specific microstructural coatings. The slurries were prepared starting from nanosized titania powders. Distilled water and alcohol were used as solvents and appropriate dispersing agents were employed to stabilize the suspensions. An external injection system that ensures the atomisation and radial injection of the suspension into Ar-H2 plasma under atmospheric conditions was designed. The coatings were characterized by scanning electron microscopy and differences in the microstructure of the deposits were observed. Efforts were made to understand the relationship between liquid feedstock properties, injection/plasma parameters and coatings microstructural characteristics.
Wear and Corrosion Resistant Amorphous / Nanostructured Steel Coatings For Replacement of Electrolytic Hard Chromium
Authors: Branagan D.J. , Marshall M.C. , Meacham B.E. , Aprigliano L.F. , Bayles R. , Lemieux E.J. , Newbauer T. , Martin F.J. , Farmer J.C. , Haslam J.J. , Day S.D. 
Published: September 2022

Abstract
In severe corrosive or abrasive environments, steel is rarely used since the range of properties available, in existing steels, are insufficient, resulting in the prevalent usage of either corrosion resistant materials like nickel based superalloys or abrasion resistant materials like tungsten carbide based hardmetals. Recently, a host of carbide based alloys including WC-Co-Cr, NiCr-Cr3C2, WC-WB-Co etc. have been developed in an attempt to bridge the gap between providing both wear and corrosion protection. Data will be presented showing how a newly developed steel coating, SAM2X5, with an amorphous / nanocomposite structure can bridge the gap between conventional metallic alloys and ceramic hardmetal performance with excellent combinations of properties including corrosion resistance superior to nickel base superalloys in seawater / chloride environments and wear resistance approaching that of tungsten carbide. The unique combination of damage tolerance developed should be especially applicable for the replacement of electrolytic hard chromium coatings.
Nanostructured Photocatalytic Titania Coatings Elaborated by Suspension Plasma Spraying
Authors: Toma F.-L. , Bertrand G. , Lamy S. , Klein D. , Coddet C. , Meunier C. 
Published: September 2022

Abstract
This paper deals with the elaboration of titanium dioxide coatings designed for photocatalytic applications, obtained by suspension plasma spraying (SPS), an alternative of the atmospheric plasma spraying (APS) in which the material feedstock is a suspension of the powder to be sprayed. Two different TiO2 powders were dispersed in distilled water and ethanol and injected in Ar-H2 or Ar-H2-He plasma under atmospheric conditions. SEM and XRD analysis were performed to study the microstructure and surface features of the titania coatings. Photocatalytic efficiency of the elaborated samples was evaluated from the conversion rate of different air pollutants: NOx and SO2. The present results showed that the suspension plasma spraying allows to produce reactive surfaces for the removal of air pollutants that in the same working conditions, present a higher photocatalytic activity compared to that of the initial raw powders.
Preparation of an SOFC LSM/YSZ Composite Cathode by Air Plasma Spraying
Authors: White B.D. , Kesler O. , Ben-Oved N. , Burgess A. 
Published: September 2022

Abstract
A porous composite cathode containing (La0.8Sr0.2)0.98MnO3 (LSM) and yttria stabilized zirconia (YSZ) for use in a solid oxide fuel cell has been produced by air plasma spraying. Deposition was carried out using axial powder injection for increased deposition efficiency and composition control. A plasma composed of argon and nitrogen was used to decrease processing costs and avoid decomposition of the cathode material during deposition. Preliminary investigations focused on determining the range of plasma conditions under which each of the materials could be successfully deposited separately. A set of conditions was thereby determined that were suitable for the deposition of a composite cathode from pre-mixed LSM and YSZ powders. Graphite pore former was added to the powder mixture in order to achieve sufficient porosity in the final coating. A tape cast YSZ electrolyte was used as the substrate for the deposition of the cathode and also as the mechanical support layer in the finished cell. Following deposition of the cathode, an anode was produced by traditional wet ceramic processing techniques. Plasma sprayed cathode was characterized by SEM, EDX, and XRD, and the electrochemical performance of the full fuel cell was evaluated.
Properties of Polymer Coatings Fabricated by Low Temperature High Velocity Air Fuel Spraying
Authors: Yuan Xiaojing , Wang Hangong , Hou Genliang , Zha Bailin 
Published: September 2022

Abstract
The fracture behavior of polymer coatings fabricated by low temperature high velocity air fuel (LTHVAF) spray was investigated. It was shown that the coatings were dense and had a mean bonding strength of 13.5 MPa. During the tensile stress process, the fracture occurred in the interior of the coatings, which indicates that the cohesive strength within coatings is less than the bonding strength between the coatings and substrate. A significant amount of crazing and honeycombed holes existed in the fracture surface. Under a tensile stress, cracks initiated at porous defects in the coatings. Dispersed particles interrupted the crack expansion, and caused a change in direction of crack propagation.
Tailoring of Wire Feedstock and Processing Conditions in High Velocity Combustion Wire Spraying
Authors: Wielage B. , Wank A. , Rupprecht C. 
Published: September 2022

Abstract
Though wire flame spraying is a relatively old thermal spray process, modern equipment permits production of high quality coatings featuring outstanding homogeneity, high density and low roughness due to increased particle velocities as a result of increased combustion gas velocity. Typically spray particles are accelerated to velocities exceeding 250 m/s, if the wires are atomized adequately. In order to make a wide spectrum of coating materials available for wire flame spraying use of cored wires needs to be considered. A high speed camera is used to determine the particle velocity depending on process conditions for massive, grooved cored and tube cored AISI 316L wires. Thereby the influence of the wire design without simultaneous influence by the chemical composition is studied. Additionally nickel based carbide reinforced coatings are sprayed and characterized concerning their microstructure and properties in use.
Simulations of Curvature Evolution Splat-Substrate Systems under Thermal Cycling
Authors: Qu M. , Wu Y. , Gouldstone A. 
Published: September 2022

Abstract
The mechanical behavior of single splats on substrates can provide insight into a number of critical coating aspects, including stress evolution, inelastic behavior, and adhesion. Single splat studies provide a theoretically sound base for the understanding of properties, as they are essentially thin film structures on substrates – a geometrically simple arrangement. However, the experimental measurement of splat properties is non-trivial. Previous work has shown that residual stresses and hardness of splats can be measured successfully using X-ray diffraction and nano-indentation, respectively. Here we present the development of a new technique for the determination of in-plane splat properties, including modulus and flow stress, as well as splat-substrate adhesion. This method is based on the widely-used substrate curvature technique, and adaptations of the Stoney formula for electronic thin films. Critical aspects of the continuum-based analysis, including the effects of splat geometry and/or partial debonding, are discussed.
Optical Coherence Tomography for the Inspection of Plasma-Sprayed Ceramic Coatings
Authors: Veilleux J. , Boulos M. , Moreau C. , Lévesque D. , Dufour M. 
Published: September 2022

Abstract
Optical coherence tomography (OCT) is evaluated as a promising technique for microstructure characterization of plasma-sprayed ceramic coatings. OCT combines the principles of low coherence interferometry and optical heterodyne detection to obtain both a high sensitivity to weakly backscattered light and a high axial resolution. It can be used to accurately locate interfaces where the refractive index changes abruptly within translucent materials. In the present work, OCT cross-sectional images of thin yttria-stabilized zirconia (YSZ) coatings are considered. The interferograms forming the images are analyzed individually to successfully gather information related to light penetration depth inside coatings. The interferogram analysis allows the evaluation of the refractive index of the YSZ non-transformable tetragonal phase.
Evaluation of Fatigue Properties of Various Thermal Spray Coatings
Authors: Siegl J. , Adámek J. , Kovářík O. , Dubský J. , Chráska P. 
Published: September 2022

Abstract
Thermal spray is a flexible technique enabling deposition of wide choice of feedstock materials including ceramics, metals or the mixture of both. Various spray technologies are available, such as different types of thermal plasma methods, electric arc based methods, HVOF and other combustion methods. Obviously, the fatigue properties of coated bodies will differ based on the choice of feedstock material and on the spray technology used. Comparison was made of fatigue properties of bodies with Alumina, Ni-5wt%Al and composite coatings produced by gas and water stabilized plasma spray. It has been found, for instance, that Alumina coatings sprayed by water stabilized plasma torch (WSP) had substantially increased fatigue life times of specimens compared to specimens with coatings of the same feedstock deposited by the gas stabilized plasma torch. Measured fatigue data were related to a detailed structural characterization of the tested coatings. Obtained results are discussed with regard to our previous results obtained during fatigue tests of specimens with one-component coatings.
Laser Cladding of Ni-Cr-B-Fe-Al Alloy on a Steel Support
Authors: Levcovici S.M. , Gheorghies C. , Boiciuc S. , Levcovici D.T. 
Published: September 2022

Abstract
In order to increase the wear and corrosion resistance of 0.45% C surface steel layers, a multilayer coating was tested by injection of a powder with 8.9% Cr, 4.5% Fe, 5.1% B, 2.4% Al, 0.6% Cu and all remainder of Ni in the melted bath produced using a CO2 continuous wave laser. To determine the optimal melting regime, the layers obtained by different laser conditions were characterized by macro and microstructure analysis, as well as a phase qualitative analysis by X-ray diffractometry and microhardness analysis.
Laser Post-Treatment of Plasma Sprayed Al2O3-Cr2O3 Coatings
Authors: Dubský J. , Kolman B. , Chráska P. , Jančárek A. 
Published: September 2022

Abstract
Chromia admixture to alumina feedstock is used to block the formation of γ-Al2O3 in plasma sprayed coatings. In this work, a mechanical blend of alumina-chromia powders was used with the water stabilized plasma to make thick coatings. When additional post-treatment by a quasi-continuous laser was applied to the surface, the amount of the corundum phase substantially increased. Careful examination of the treated surface revealed that the individual splats at and near the surface were fully remelted and the structure is formed by a homogeneous phase with no visible splat boundaries. Segregation of Chromium has been detected in the remelted zones, which strongly affects the final properties of coatings. Fast melting and cooling of the ceramic material under certain laser parameters may result in the formation of undesirable cracks between traces of individual passes of the laser beam.
Thermal Barrier Coating Systems for Gas Turbine Engines by Thermal Spray and EBPVD—A Technical and Economic Comparison
Authors: Feuerstein A. , Knapp J. , Taylor T. , Ashary A. , Bolcavage A. , Hitchman N. 
Published: September 2022

Abstract
The most advanced thermal barrier coating (TBC) systems for aircraft engine and power generation hot section components consist of EBPVD applied yttria stabilized zirconia and platinum modified diffusion aluminide bond coating. Thermally-sprayed ceramic and MCrAlY bond coatings, however, are still used extensively for combustors and power generation blades and vanes. This paper highlights the key features of plasma spray and HVOF, diffusion aluminizing and EBPVD coating processes. The coating characteristics of thermally sprayed MCrAlY bondcoat as well as low density and dense vertically cracked (DVC) Zircoat TBC are described. Essential features of a typical EBPVD TBC coating system, consisting of a diffusion aluminide and a columnar TBC, are also presented. The major coating cost elements such as material, equipment and processing are explained for the different technologies, with a performance and cost comparison given for selected examples.
Micro and Nanomanufacturing Technologies – A Case for Using Thermal and Cold Spray Techniques
Authors: Jackson M.J. , Ahmed W. 
Published: September 2022

Abstract
There is a plethora of micro and nanofabrication processes that have been developed over the past ten years for use in the electrical and mechanical industrial sectors. Processes such as optical lithography, x-ray lithography, LiGA, selective laser sintering, laser micromachining, wet and dry plasma etching, casting, molding, etc., are already well established. However, newly emerging processes such as laser nanofabrication, diamond nanogrinding, thermal spray and cold gas dynamic manufacturing, etc., have yet to realize their potential. The future of micro and nanomanufacturing lies in the ability to convert micro and nanofabrication techniques into mass production manufacturing processes where small-scale products can be economically manufactured in a short period of time. This may be achieved by combining micro and nanoscale processes, or by combining ‘top down’ and ‘bottom up’ manufacturing techniques. The development of so-called hybrid manufacturing processes is set to take center stage in the future development of micro and nanomanufacturing processes. This paper will focus on current developments in the field of micro and nanomanufacturing and highlights the importance of processes such as thermal spray and cold gas dynamic manufacturing.
Hypersonic Plasma Particle Deposition – A Hybrid between Plasma Spraying and Vapor Deposition
Authors: Hafiz J. , Mukherjee R. , Wang X. , McMurry P.H. , Heberlein J. V. R. , Girshick S.L. 
Published: September 2022

Abstract
In the hypersonic plasma particle deposition process, vapor phase reactants are injected into a plasma and rapidly quenched in a supersonic nozzle, leading to nucleation of nanosize particles. These particles impact a substrate at high velocity, forming a coating with grain sizes of 10 to 40 nm. As previously reported, coatings of a variety of materials have been obtained, including silicon, silicon carbide, titanium carbide and nitride, and composites of these, all deposited at very high rates. Recent studies have shown that slight modifications of the process can result in nanosize structures consisting of single crystal silicon nanowires covered with nanoparticles. These nanowires are believed to grow in a vapor deposition process, catalyzed by the presence of titanium in the underlying nanoparticle film. However, simultaneously nanoparticles are nucleated in the nozzle and deposited on the nanowires, leading to structures that are the result of a plasma CVD process combined with a nanoparticle spray process. The combination of these two process paths opens new dimensions in nanophase materials processing.
Development of Composite Nano-Coatings by Comprehensive Thermal Plasma Deposition
Authors: Huang H.J. , Li J.Q. , Ma T. , Eguchi K. , Yoshida T. 
Published: September 2022

Abstract
The development of novel thermal barrier coatings (TBCs) by a 300 kW twin hybrid plasma spraying system was conducted as a case study of the integrated and comprehensive thermal plasma deposition technique, namely, the combination of thermal plasma powder spray (TP-PS) and the thermal plasma physical vapor deposition (TP-PVD). Microstructures of the coatings deposited from either vapor or melted droplets were tailored to compose peculiar functional layered Al2O3/YSZ and YSZ/YSZ coatings in the comprehensive deposition processes, aiming to meet the severe requirements of the next-generation TBCs. Even for the vapor deposition, ultrafast deposition rate over 150 µm/min was achieved. These results showed that the comprehensive spraying process has successfully integrated the potentials of different thermal plasma deposition techniques, and the effectiveness and flexibility of this process made it very promising to be applied in future coating industry.
Properties of WC-10Co-4Cr Powders and Coatings Made of Recycled Hard Metal
Authors: Kanerva U. , Kosme K. , Lagerbom J. , Vuoristo P. , Karhumaa T. 
Published: September 2022

Abstract
HVOF sprayed WC-CoCr coatings are used to in wear and corrosion applications. Commercially available hard metal powders for HVOF spraying are normally manufactured from virgin raw materials. In the present work, the possibility to manufacture WC-CoCr spray powder with excellent properties and quality from recycled cemented carbide tools and tool bits was studied. The powders were manufactured from hard metal scrap by a series of processing steps. The powders were sprayed by using the HVOF process. The properties of the powders and coatings were studied and compared to those of commercially available state-of-the-art WC-CoCr powders and coatings with the same nominal composition. Experimental powders worked well during spraying and the quality of the coatings was equal or even better than that of the reference coatings. Equal or even better corrosion properties compared to reference coatings were obtained with the new spray powder manufactured from recycled hard metal.