bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance Analysis and Modeling of Thermally Sprayed Resistive Heaters
Authors: Lamarre J.-M. , Marcoux P. , Perrault M. , Abbott R. C. , Legoux J.-G. 
Published: November 2022

Abstract
Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by eliminating the air gap between the heater and the surface to be heated. This paper is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated using a plasma-sprayed alumina dielectric insulator and a wire flame sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425°C for up to four months. SEM cross-section observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as: emissivity and time-dependent temperature profile (infra-red camera), resistivity (four probe technique), thermal diffusivity (laser flash method) and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated.
Effect of Suspension Characteristics on Microstructure of Suspension Plasma Sprayed SiC Submicron Coatings
Authors: Mubarok F. , Puranen J. , Vuoristo P. , Johnsen R. , Espallargas N. 
Published: November 2022

Abstract
Thermal spraying of pure SiC is difficult due to decomposition issues at elevated temperatures. However, the development of suspension plasma spray opens a new path to investigate the deposition of this material since the liquid carrier can hinder this phenomenon. The present work investigates a new route for producing SiC submicron structured coating by suspension plasma spraying (SPS). Classical SiC manufacturing routes using suspension (i.e: spray drying, tape casting) are studied regarding their feasibility to be used on suspension plasma spraying. Aqueous-based suspensions containing 10 wt.% SiC powder (0.60 µm) along with sintering additives are dispersed and stabilized. Both suspensions are sprayed on martensitic stainless steel substrate (AISI 440C) to achieve finely structured and dense coatings. Digital image analysis, X-ray diffraction and scanning electron microscopy are utilized to characterize the coating microstructures. Their dependency on suspension characteristics and spray operation parameters are discussed with respect to the final coating performance.
Silicon Carbide Based Plasma Sprayed Coatings
Authors: Tului M. , Giambi B. , Pulci G. , Valente T. 
Published: November 2022

Abstract
Coatings containing up to 65 volume % of silicon carbide were deposited by plasma spray. Potential applications can be found in the protection of CMC (Ceramic Matrix Composite) against wear and high temperature oxidation. It is well known that SiC can not be deposited by thermal spray because it decomposes before melting. To face this problem, a mixture of SiC and ZrB2 was deposited, since those two compounds form an eutectic phase, at a temperature lower to the one of SiC decomposition. Coatings microstructure was characterised by XRD, SEM, and EDS, confirming the presence of SiC in the deposited layer and the formation of the eutectic phase during spraying. Samples of the coatings were exposed in air at high temperature, in the range between 1373 and 1873 K. The oxide scale was investigated by means of SEM and EDS. It was constituted by a SiO2 layer, which includes islands of ZrO2. Test results showed the good potentiality of the material investigated to be used as a protection against the high temperature oxidation.
Synthesis of Porous Super-Capacitor Electrodes using the SPPS Deposition Technique
Authors: Golozar M. , Chien K. , Coyle T. W. 
Published: November 2022

Abstract
Electrical double-layer capacitors (EDLCs) owe their large capacitance to high specific surface area carbon-based electrode materials adhered to a current collector via an adhesive. However, recent studies attribute greater electrical energy storage capacity to transition metal oxides/nitrides: a new generation of electrode materials for use in super-capacitors with mixed double-layer and pseudo-capacitive properties. Solution Precursor Plasma Spray (SPPS) deposition is a technique that allows coatings to be fabricated with fine grain sizes, high porosity levels, and high surface area; characteristics ideal for application as transition metal oxide super-capacitor electrodes. A liquid injection apparatus was designed to inject the liquid into the DC-arc plasma and to investigate the effects of various operating parameters such as spray distance, solution concentration and solution flow rate on the chemistry and surface topography of the deposits. Understanding and controlling the evolution of the precursor solution in the DC-arc plasma jet is crucial in producing coatings of the desired structures. DTA/TGA, SEM, XRD, and electrochemical analyses performed to characterize the coatings will be discussed, and the potential of the deposits for use in super-capacitors will be assessed.
Deposition of Nickel-Yttria Stabilized Zirconia and Nickel-Samarium-Doped Ceria by Solution Precursor Plasma Spraying for Solid Oxide Fuel Cells
Authors: Metcalfe C. , Lay E. , Kesler O. 
Published: November 2022

Abstract
Nickel – yttria stabilized zirconia coatings and nickel – samaria doped ceria coatings were fabricated by solution precursor plasma spraying using the Northwest Mettech Axial III plasma torch. Three sets of plasma spray parameters were used resulting in comparatively low, intermediate, and high plasma powers of 63 kW, 102 kW, and 152 kW, respectively. The high and low power conditions resulted in powdery type coatings with poor adhesion to the substrate and between particles. The intermediate power conditions resulted in harder coatings with improved adhesion and electrical conductivity.
Influence of Boron Content on Microstructure and Properties of Wire-Arc Sprayed Fe-Based Coating
Authors: Zhou Z. , He D. Y. , Zhang G. Z. , Li R. , Jiang J. M. 
Published: November 2022

Abstract
A series of FeCrBCSi coatings were prepared by two-roll wire-arc spraying to investigate the influence of the boron content on the microstructure and properties of the coatings. Microstructural studies show that the as-deposited coatings present a dense layered structure with the porosity around 3%, and are primarily composed of a composite structure of amorphous phase and nanocrystalline phase. It is found that the addition of boron content within the composition range examined exhibits a significant effect on the phase component, as well as the microhardness and wear resistance of the coatings. The optimal composite phase structure, in terms of higher amorphous fraction and lesser nanocrystalline size distribution, leads to the relatively best performance of the coating with 26% boron added. The relative wear resistance of this coating is about 18 and 4 times higher than that of the Q235 steel and commercially available SHS 7170 coating, respectively, therefore wire-arc sprayed FeCrBCSi coating could be an effective and economic approach to withstand wear environment.
Investigation of Heat Treatment on Cold Sprayed Aluminum Coatings on Magnesium Substrates with Different Status
Authors: Bu H. , Jodoin B. , Yandouzi M. , Lu C. 
Published: November 2022

Abstract
Large pure aluminum powders were deposited on as cast-, T4- and T6-AZ91D magnesium substrates using cold spray. Heat treatment was applied to the coated components under vacuum at 400°C for different holding time. The effects of the heat treatment on the microstructure as well as the coating/substrate adhesion strength were investigated. Thick (~ 400µm) and dense (&lt;1% porosity) Al coatings have been obtained on the three different substrates. During heat treatment, Mg17Al12 (β) and Al3Mg2 (γ) intermetallic phases were formed at the Al/Mg interface and the thickness of the intermetallics layers increased with the holding time. No significant thickness difference of the intermetallics layers were observed on as cast- and T6-AZ91D substrates, while thicker layers took place on the T4- substrate. It is believed that the higher Al concentration within the T4-AZ91D material could be beneficial for intermetallic growth because less enrichment is required to reach the critical level for intermetallic formation in the substrate. Shear strength tests were performed on the as sprayed and after heat treatment coatings. The results revealed lower adhesion strength in the samples after heat treatment than the as sprayed ones which is attributed to the presence of brittle intermetallics layers at the coating/substrate interface.
Sliding Wear Behavior of HVOF Sprayed Coatings, Suitable for Piston Rings Application
Authors: Houdková Š. , Kašparová M. , Zahálka F. 
Published: November 2022

Abstract
The HVOF sprayed wear resistant hardmetal coatings with favourable sliding properties are suitable for increasing the lifetime of sliding applications, such as pistons of combustion engines, pumps and other hydraulic devices. In practice, the coatings face the problem of their interaction with other media, in the case of sliding wear usually lubricants. In the paper, the friction properties of five different HVOF sprayed coatings are evaluated by pin-on-disk test according to ASTM G-99 under dry and lubricated conditions and lubricated block-of-ring test according to ASTM G77. Several types of lubricants designed for combustion engines were used to compare their influence on coatings sliding wear behavior. Based on the results, the suitability of coatings for the application on the engines parts is discussed and the effect of counterpart material and different types of lubricants on the coefficient of friction and coatings wear rate is analyzed. It was confirmed, that the CrC-based coating are more suitable for the application under the condition corresponding to combustion engines, e.g. elevated temperature and steel counterpart, than the WC-based coatings. From the group of CrC-based coatings, the superior behavior was observed at the CrC-CoNiCrAlY coating, the matrix material of which offers further enhancement of the sliding wear behavior.
Electrical Properties of Al2O3-TiO2 Plasma Sprayed Coatings for Electrode of Corona Discharge
Authors: Abukawa S. , Takabatake T. , Namba Y. , Tani K. 
Published: November 2022

Abstract
Thermal sprayed ceramic coatings are well used as the electrode of corona discharge treatment in order to modify the surface of many kinds of films and papers due to its superior durability and adaptability. Some kinds of Al2O3-TiO2 were sprayed by APS on the parallel plate electrodes, and output power of corona discharge generated by the electrodes was measured by using Sawyer-Tower circuit. In addition, discharge output power was calculated with an equivalent circuit of corona discharge. By comparing them, effects of the electrical property of the coating on discharge was researched. As a result, the electrostatic capacitance of the coatings influences the impedance of the whole circuit, and higher relative permittivity of the coating brought higher output power in a constant voltage.
Innovative Testing Method for Interconnected Porosity of Thermally Sprayed Ceramic Coatings Using Electroplating
Authors: Harada Y. , Takatani Y. , Tani K. 
Published: November 2022

Abstract
New concept and method of testing for the interconnecting porosity of thermally sprayed nonconductive ceramic coatings is proposed. This process is useful to differentiate the open porosity from the closed porosity. Thermally sprayed ceramic coating with metallic substrate is plated, and the intergranular gaps in the coating are filled by deposited metal. Typically, 304 stainless steel substrate deposited with atmospheric plasma sprayed alumina coating is immersed in copper(II) sulphate bath, and electroplated. Inward of the alumina coating, plating solution penetrates toward the interface of coating/substrate via interconnected porosity, and attains the coating-substrate interface to deposit metallic copper. Deposit of copper is gradually grown up along the coating intergranular. The exposure of deposited copper on the coating surface can be visible. Because these phenomena occur only in the interconnected pore structure, it is easy to differentiate the interconnected porosity from the closed porosity. Also the proposed process suggests the unprecedented possibility of manufacturing method of three-dimensional structure of thermally sprayed ceramic coating.
Modern Applications of the Low Pressure Cold Spray
Authors: Kashirin A. , Klyuev O. , Buzdygar T. , Shkodkin A. 
Published: November 2022

Abstract
The main advantage of the cold spray process is minimal influence on the substrate properties with sufficiently high bond strength. This advantage allows metal coating to be applied to the specific objects which were never subjected to the thermal spray process. The examples of the low pressure cold spray application to the glass objects, magnet sensors and electronic elements are presented and discussed.
Annealing Effect on the Intermetallic Compound Formation of Cold Sprayed Fe/Al Composite Coating
Authors: Wang H.-T. , Li C.-J. , Ji G.-C. , Yang G.-J. 
Published: November 2022

Abstract
In this paper, an iron/aluminum composite coating was prepared by cold spraying using iron and aluminum powder mixture and then annealed to aim at forming iron aluminides by suitable annealing treatment. The annealed coating was characterized using X-ray diffraction (XRD) to determine the coating phases and scanning electron microscope (SEM) with an EDXA energy dispersive spectroscopy (EDS) to examine the coating microstructure evolution. Results showed that the Fe2Al5 intermetallic layer along some regions of the aluminum-iron boundaries forms after annealing at a temperature of 450°C, where true metal to metal contact had occurred. The content of Fe2Al5 phase increased with raising annealing temperature. It was observed that some cracks were developed in Fe2Al5 layer after annealing treatment at a high temperature of 600°C.
Effect of In-situ Softening on the Deposition Behavior of Particles by Controlling Gas Stream Traversing During Cold Spraying
Authors: Yang G.-J. , Wang J. , Li C.-J. , Zhang Q. , Li C.-X. 
Published: November 2022

Abstract
The deposition behavior of particles during cold spraying is determined by plastic deformation of both substrate and impinging spray particles. In this paper, the in-situ heating and subsequent softening of the local substrate were examined to reveal their influence on the deposition behavior of spray particles and the microstructure and property of the cold-sprayed 316L stainless steel and copper coatings. Results show that the temperature of the substrate surface, where the spray gas stream and high velocity particles were projected on, increased to 300°C when the gas temperature was 500°C. Such effect is referred to as the in-situ substrate heating. The in-situ heating of the substrate surface was enhanced with the decrease in the gun nozzle traverse speed. With the decrease of nozzle traverse speed from 100 to 20 mm/s, the relative deposition efficiency significantly increased and the porosity of cold-sprayed 316L coatings decreased from 5.6% to 2.5%, and the micro-hardness of the coatings increased from 283 Hv to 351 Hv. The influence of the nozzle traverse speed on the microstructure and property of cold-sprayed coatings is discussed based on the influence of the in-situ heating and softening effect of substrate surface on its deformation behavior and particle deposition upon the impact of spray particles. The in-situ substrate surface heating is proposed as an essential processing parameter as a function of gun traverse speed during cold spraying.
Thermal Analysis of Cold-Sprayed Copper Coatings
Authors: Alishir F. , Nekoumanesh H. , Assadi H. 
Published: November 2022

Abstract
In this study copper coatings were deposited by cold spraying, under different spraying conditions. Microstructure of the coatings was investigated by optical and scanning electron microscopy. Additionally, differential scanning calorimetry (DSC) and thermal gravimetric analysis were used to examine the quality of the coatings, especially with regards to the extent of the bonded area between the particles. The DCS results indicated exothermic reactions at certain temperatures, which revealed correlations with the spraying conditions and some of the observed microstructural features. In view of these results, it is concluded that thermal analysis can be utilized reliably to assess the quality of coatings, and in particular, to examine the fraction of bonded areas in cold-sprayed deposits.
Influence of Deposition Conditions and Heat Treatment on Tensile Strength of Cold Spray Aluminium Coatings on Al2O3 and AlN Substrates
Authors: Kuemmel S. , Grund T. , Loeschner P. , Wielage B. 
Published: November 2022

Abstract
A novel process to produce dense, well adherent aluminium coatings on ceramic materials is cold gas spraying (CGS). The mechanical, physical and chemical processes leading to the bonding of cold-sprayed coatings on ceramic substrates have only been described rudimentarily. A survey of the literature on adhesion mechanisms of cold spray coatings is given, where influences on bond strength are discussed and parameters identified. Using the example of coating Al2O3 and AlN substrates with pure aluminium via cold gas spraying, a process and substrate parameter variation is presented. A significant raise in tensile coating strength was seen at elevated substrate temperatures and after subsequent annealing. Tensile strength also depended on chemical composition and roughness of the substrate. The results allow the discussion of the bonding mechanisms of cold spray aluminium on ceramic substrates as a function of deposition and annealing parameters.
Interface Reactions in Composite Coatings Deposited by Cold Spray and Detonation Spraying
Authors: Leshchynsky V. , Bielousova O. , Ryashin N. , Yadroitsava I. , Smurov I. 
Published: November 2022

Abstract
Deposition of Metal Matrix Composites (MMC) has been the subject of extensive research in the recent years. The desired functional properties of a composite coating can be achieved by analyzing and controlling the major structural processes taking place during deposition. The latter are reactions at the particle-particle and particle-substrate interfaces which can be controlled by applying advanced spraying technologies. Cold Spray (CS) and Computer Controlled Detonation Spraying (CCDS) are well-proven reliable methods for deposition of composite coating. The energy (thermal and kinetic) imparted to the particles-in-flight by CS and CCDS allows initiating interface reactions that will define distinct properties of the deposited composite layers. The applied spraying technologies are characterized by different ratio of thermal-to-kinetic energy that results in different conditions of the compounds interaction. The objective of the present study is to define the effect of CS and CCDS technologies on structure and properties of Al-Ti-based composite coatings by analyzing intermetallic reactions occurring during the process. It is shown that both CS and CCDS composites present differently sized zones of interfacial reactions.
Corrosion Behaviour of HVOF-Sprayed Ni-20Cr Coating in a Molten Salt Environment at 900°C
Authors: Kaushal G. , Singh H. , Prakash S. 
Published: November 2022

Abstract
HVOF thermal spray technique was used to deposit Ni-20Cr coating on a ASTM-SA213-T22 boiler steel. The corrosion behaviour was investigated for the uncoated and HVOF spray Ni-20Cr coated boiler steel in a molten salt environment (Na2SO4-60%V2O5) at 900°C for 50 cycles. Each cycle consisted of 1 hour heating in the silicon carbide tube furnace followed by 20 min cooling in air. Mass change technique was used to approximate the kinetics of high temperature corrosion. The uncoated sample suffered intensive spallation along with a significant mass gain as compared to the coated sample. The exposed specimens were characterized by X-ray diffraction [XRD] and scanning electron microscopy/energy dispersive spectroscopy [SEM/EDS]. It was observed that HVOF sprayed Ni-20Cr coating was suitable to provide high temperature corrosion resistance to the given steel in the said(salt) environment.
Microstructure and Properties of FeAl Coatings Prepared by APS, LPPS and HVOF
Authors: Yang D.-M. , Tian B.-H. , Gao Y. 
Published: November 2022

Abstract
The FeAl intermetallic compound coatings were sprayed by low pressure plasma spraying (LPPS), air plasma spraying (APS) and high velocity oxy-fuel spraying (HVOF). The influence of three kinds of thermal spraying processes on the microstructure, microhardness, elastic modulus and fracture toughness of coatings were investigated. The results showed that the APS and HVOF coatings exhibited similar microhardness, about 540HV0.3, which is much lower than that of LPPS coatings, 860HV0.3. The elastic modulus measured for APS, HVOF and LPPS coatings using Knoop indentation were 96, 84, 176GPa, respectively. The APS coatings were also observed to have lower elastic modulus values in the in-plane direction than those in the perpendicular direction, as a result of microcracks scattered within the coatings. In fracture toughness tests, the LPPS coatings revealed the lowest fracture toughness, as compared with other two spraying processes, indicating low porosity and crack levels are related to low fracture toughness. From these results, it appeared that potential improvements to certain mechanical properties can be achieved using low pressure plasma spraying process.
Suppressing Oxidation of Ni-Cr Alloy with Addition of Si, B and C in Atmosphere Plasma Spray Process
Authors: Zeng Z. , Sakoda N. , Tajiri S. , Kuroda S. , Komatsu M. 
Published: November 2022

Abstract
Oxidation is a serious issue for thermally sprayed alloy coatings, especially in atmospheric plasma spray (APS) process, by which it is believed to be impossible to obtain alloy coatings with low oxide content. Oxidation behavior of Ni20Cr alloy and NiCrSiBC alloy in APS were compared by evaluating collected in-flight particles and sprayed coatings in our previous study. The results clearly show that the oxide content in the in-flight particles and coating of NiCrSiBC alloy was significantly lower than that of Ni20Cr alloy. In the present study, further study of the surface oxide layer of NiCrSiBC coating was carried out by TEM, which showed 10 nm thick oxygen enriched layer. The effects of particle temperature and velocity on the oxidation of the NiCrSiBC alloy were investigated. It was found that increasing particle temperature and velocity did not affect the oxidation of inflight particle of the NiCrSiBC alloy but significantly increased the oxidation after particle impacting substrate. The results are discussed in conjunction with effectiveness of preferential oxidation of Si, B, C and simultaneous vaporization of the formed oxides on suppressing in-flight oxidation and influence of a large amount of sub-particles produced upon impacting substrate on oxidation characteristics when increasing plasma power.