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Journal of Thermal Spray Technology
Journal Prestige (SJR): 0.688  Citation Impact (citeScore): 2 Number of Followers: 5  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1544-1016 - ISSN (Online) 1059-9630 Published by Springer-Verlag  [2468 journals]
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- Micro-cold Spray Deposition of YSZ Films from Ultrafine Powders Using a
Pressure Relief Channel Nozzle-
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Abstract: Abstract The use of ultrafine powders in the micro-cold spray (MCS) process, also referred to as the aerosol deposition method, typically results in porous and/or poorly adhering films because the particles do not impact at a high enough velocity for sufficient plastic deformation and interparticle bonding to occur. Under typical operating conditions, particles < 100 nm accelerate to high velocities but then are slowed by the stagnant gas in the bow shock that forms just upstream of the substrate. Using larger particles reduces particle slowing, but large particles can cause erosion of the film at high impact velocity, decreasing deposition efficiency. In this study, a pressure relief channel nozzle using helium as a carrier gas is proposed such that high-velocity deposition of yttria-stabilized zirconia particles as small as 10 nm in diameter is possible. This is well below the size range of powders previously used for MCS. The proposed nozzle design increases impact velocities for 10, 20, and 50 nm particles by ~ 880, 560, and 160 m/s, respectively, when compared to a conventional nozzle. Experimental deposition of ultrafine 8YSZ powder shows that the pressure relief channel nozzle results in lower porosity and more uniform deposits, with a ∼ 186% increase in deposition efficiency.
PubDate: 2024-08-27
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- Simulation of the Axial III Plus Plasma Torch and Its Arc Fluctuations
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Abstract: Abstract The demand for utilizing the Axial III Plus plasma spray system has prompted the numerical modeling of its arc plasma torch, integral to creating a digital twin of the suspension plasma spray process. The Axial III Plus plasma torch is a highly efficient and reproducible tool with a unique three-torch exit jet arrangement that allows the axial injection of solid/liquid feedstock, not possible with a single cathode/anode–plasma torch setup. In this study, we employ the local thermodynamic equilibrium approximation of the magnetohydrodynamic (MHD) model to simulate plasma flow inside the single gun plasma torch of Axial III, considering electrode–plasma interactions. Describing electric arc dynamics during restrike proves intricate; thus, a restrike model is used relying on cutoff criteria based on a threshold value Eb of the predicted radial electric field at the electric arc fringes. The model successfully replicates typical electric arc behavior and saw-toothed voltage profiles during restrike, notably capturing the characteristics of the Axial III anode’s unique and complicated design variations in electric arc motion and its corresponding arc voltage profile. Analysis extends to studying variations in Eb, which directly influence mean electric arc length, arc voltage, and mean arc spot time, potentially impacting energy generation and losses in the torch. These findings provide a valuable foundation for future simulations of this design, especially with swirl gas injection and ternary gas mixtures.
PubDate: 2024-08-23
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- Influence of Friction Stir Spot Processing on Grain Structure Evolution
and Nanomechanical Behavior of Cold-Sprayed Al Coating on Ti Substrate-
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Abstract: Abstract The grain structure evolution and nanomechanical behavior of cold-sprayed Al coating on Ti substrate with friction stir spot processing (FSSP) were studied by the electron backscatter diffraction and nanoindentation methods. The low-angle boundaries (LAGBs) fraction and the density of the geometrically necessary dislocations (GNDs) decreased from the base zone (BZ) to the stir zone (SZ). The average grain size, the LAGBs fraction and the density of the GNDs were various in different locations of the SZ, which can be attributed to the variety of local shear strain and temperature gradient during FSSP. The B/ \(\stackrel{{-}}{\text{B}}\) component, the C component, and the A*1/ A*2 component were mainly developed in the SZ. The highest intensity of the B/ \(\stackrel{{-}}{\text{B}}\) component appeared in the 3/8D of the SZ, indicating that the plasticized materials flowed downward experienced the highest shear strain. The materials in the heat affected zone (HAZ) underwent static recrystallization, while the continuous dynamic recrystallization (CDRX) and the geometric dynamic recrystallization (GDRX) occurred in the thermo-mechanically affected zone (TMAZ) and SZ. The nano-hardness and elastic modulus of the cold-sprayed Al coating after FSSP were comparable to those of pure Al bulk. The grain size and dislocation density were the main factors affecting the nano-hardness in the SZ.
PubDate: 2024-08-22
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- Effect of Powder Oxidation on Microstructures and Mechanical Properties of
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Abstract: Abstract This study investigated the effect of powder pre-oxidation on the microstructures and mechanical properties of cold-sprayed nickel coatings. The artificially pre-oxidized nickel powders at 200, 300 and 400 °C for 5 h show the resulting oxygen contents of 0.27, 0.36 and 0.41 wt.%, as compared to 0.21 wt.% in the feedstock powder. Microstructurally, the higher oxygen contents of the impact particles significantly increased in both the number and size of the pores in the as-sprayed coatings by using the pe-oxidized powders, as a result of the porosities of 0.7, 1.5 and 3.3% compared to 0.4% by using the as-atomized powder (natural oxidation condition). Mechanically, the increased oxygen contents of powders result in the reduced properties for the as-sprayed Ni coatings, as the microhardness of 263.2 HV0.1, 245.3 HV0.1 and 236.3 HV0.1 and the tensile strength of 94, 76 and 61 MPa by using oxidized powders compared to those of 289.2 HV0.1 and 208 MPa by using natural oxidation powder. In addition, post-spray heat treatment at 800 °C for 2 h effectively reduces the small-sized pores and nonbonded particle-particle boundaries within the coatings, which is attributed to a combination effect of annealing twins and dislocation slip during heat treatment. As a result, the microhardness significantly decreased to 135.3 HV0.1, 126.7 HV0.1, 124.5 HV0.1 and 114.7 HV0.1, while the tensile strength is increased to 210, 166, 133 and 117 MPa, respectively.
PubDate: 2024-08-22
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- Fabrication and Characterization of HVOF Sprayed CoNiCrAlY-6%Al2O3 Coating
to Improve High-Temperature Oxidation Resistance-
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Abstract: Abstract Alumina nanoparticles were incorporated into CoNiCrAlY powders to fabricate an overlay coating of improved oxidation resistance for gas turbine blades via thermal spraying. In this regard, 6 wt.% alumina nanoparticles were agglomerated with CoNiCrAlY powders by modified suspension route and applied to samples of CMSX-4 nickel-based superalloy by high velocity oxygen fuel (HVOF) process. The coatings were characterized by X-ray diffraction, scanning electron microscopy and field emission scanning electron microscopy, EDS and elemental mapping, Vickers hardness and roughness measurement. Cyclic oxidation tests were performed to study the high-temperature oxidation behavior at 1100 °C. The results showed an increase in hardness, roughness and porosity with the addition of alumina nanoparticles to the coating. Furthermore, the oxidation resistance of CoNiCrAlY + 6 wt.% Al2O3 was improved as compared to conventional CoNiCrAlY after 100 cycles of oxidation; a reduction in the thickness of oxide layer and β depletion zone was observed. Formation of a dense and protective α-Al2O3 phase, instead of θ-Al2O3, was confirmed during the oxidation process in the coatings containing nanoparticles. It was concluded that nanoparticles prevent the penetration of elements to the surface and reduce the formation of non-protective oxide layer.
PubDate: 2024-08-19
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- Bonding Mechanism of Arc-Sprayed ZnAl Coatings on Polypropylene Films:
Numerical Simulation of Particle Behavior-
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Abstract: Abstract Interface microstructures of metallic coatings at end faces are critical for durability of metallic polypropylene (MPP) capacitors. However, the microstructures are difficult to be regulated efficiently due to the specificity of the polymer substrates. Therefore, ZnAl coatings were deposited at end faces of MPP capacitors by arc spraying. The temperature and velocity of in-flight droplets were regulated with different spray distance. A modified numerical simulation with a combustion model was employed to calculate the temperature and velocity of the droplets. The interface microstructures and equivalent series resistance of the capacitors were characterized. The results show that the temperature of the droplets continued to increase during the flight due to exothermic oxidation. The interface of the coatings with the spray distance of 150 mm presented a dendritic microstructure with deeper embedment depth and more bonding layers. The bonding layers reduced as the spray distance decreased to 120 mm because of the damage of the MPP layers. The embedment depth of the coatings decreased as the spray distance increased to 180 mm due to lower temperature of the droplets. The equivalent series resistance of the capacitors decreased to 7.84 mΩ with the dendritic interface microstructures. The research provides a new numerical model to optimize arc spraying and improve the quality of MPP capacitors.
PubDate: 2024-08-19
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- A Particle-Based Numerical Model for Impact-Induced Bonding in Cold Spray
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Abstract: Abstract A computational framework is proposed for modelling particle bonding in cold spray. The model is based on the commonly-held view that bonding is a consequence of jetting, namely, the large plastic strains occurring at extreme rates upon particle impact. The model incorporates a bonding criterion at contacting boundaries by introducing a novel strain-like history variable referred to as the bonding parameter conjugate to a rate-dependent evolution law. In doing so, an analogy is made with classic damage mechanics where bonding is viewed as a similar but opposite process to fracture. Two new material constants are introduced, namely, the bonding toughness and the bonding toughness rate. Furthermore, a numerical implementation of the model in the Material Point Method (MPM) is presented which, thanks to a proposed regularization technique, is free of non-physical dependence on discretization parameters. The mesh-free nature of the MPM allows avoiding the numerical issues in conventional Lagrangian and Eulerian methods such as mesh distortion and artificial dissipation. The model is calibrated numerically for aluminum-aluminum material pair using an in-house computer program. Several numerical results are presented to demonstrate that the model can accurately capture material jetting and directly relate it to bonding within the simulation.
PubDate: 2024-08-15
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- Wear and Corrosion Resistances of Arc-Sprayed FeCr Alloy and Fe-Based
Coatings for Boiler Heat Exchanger Pipelines-
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Abstract: Abstract Wear and corrosion of boiler tubes in coal-based boilers are one of the serious problems. Trying to solve this issue, FeCr alloy with 45%Cr-content coating and Fe-based coating with 13%Cr-content were arc sprayed onto carbon steel substrates to enhance both the wear and corrosion resistance of boiler heat exchanger pipelines. The microstructure, chemical compositions, and phases of the coatings were analyzed using a scanning electron microscopy, energy-dispersive spectrometer, and x-ray diffraction, respectively. The wear resistance of the coatings was assessed at 25 and 300 °C using a ball-on-disk wear tester. The corrosion resistance of the coatings was evaluated based on seawater immersion, electrochemical impedance, and polarization tests. The porosities of FeCr alloy and Fe-based coatings were 4.05 and 5.75%, respectively. The microhardness values of FeCr alloy and Fe-based coatings were 377.50 ± 46.88 HV0.5 and 666.69 ± 57.64 HV0.5, respectively. FeCr alloy coating with lamellar structure was mainly composed of FeCr solid solution phase and a small amount of Cr oxide and Fe3O4 phases, and Fe-based coating was composed of a mixture phase of amorphous and crystalline, and a small amount of Fe3O4 phase. FeCr alloy coating had better wear resistance than Fe-based coating at both 25 and 300 °C. The wear mechanisms of the coatings were also studied. The corrosion resistance of FeCr alloy coating was better than that of Fe-based coating in corrosive solutions. Therefore, FeCr alloy coating can provide better high-temperature wear resistance and anticorrosion performance for boiler heat exchanger piping, compared with Fe-based coating.
PubDate: 2024-08-14
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- Numerical Analysis of Quenching Stress in Thermal Spray Process Using SPH
Method-
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Abstract: Abstract Thermal spray is an important surface treatment technique used in many industrial applications. Thermal spray processes involve molten droplets sprayed onto substrates. Heat transfer between the droplet and the substrate at different temperatures results in sharp temperature gradients and a phase change. Quenching stresses arise as a combined effect of phase change and the thermal mismatch between materials. It is important to characterize quenching stress for predicting material durability. However, such characterization is challenging due to the complex physics involved. In this study, the smoothed particle hydrodynamics method is used to predict the quenching stress in the thermal spray process for different droplet materials, including yttrium-stabilized zirconia (YSZ), stainless steel (SS), aluminum (Al), and alumina (Al2O3) impinging on various substrate materials. The present numerical model is validated against the experiments and previous numerical studies for splat behavior, time evolution of substrate temperature, and quenching stress. A parametric study investigates the main contributing factors to quench stress. The parametric study reveals that elevated substrate temperatures reduce thermal gradient, thus quenching stress. Compared to the differences in droplet material, the quenching stress shows increased sensitivity to the substrate material. Additionally, materials with high thermal diffusivity, such as SS, exhibit lower quenching stress due to their ability to dissipate heat quickly. Conversely, materials with lower thermal diffusivity, such as YSZ, show higher quenching stress because of slower heat dissipation. These findings provide critical insights into optimizing thermal spray processes to minimize quenching stress and enhance material durability.
PubDate: 2024-08-14
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- Effect of Porosity on Abradability of YSZ Coatings
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Abstract: Abstract The effect of porosity on the wear behavior of YSZ abradable coating under simulated working conditions was studied using the high-temperature and ultra-high-speed abradability test rig. The results show that the porosity significantly influences the macroscopic morphology and abradability of the YSZ coating at the experimental temperatures of 1000 °C, with the blade tip velocity of 350 m/s, and the feed rate of 50 μm/s. The wear degree of the blade gradually decreases as porosity increases, and the incursion depth ratio (IDR) dramatically decreases. When the porosity reaches its maximum value, the wear scar of the coating is smoothest, and there is no discernible wear on the blade, the IDR value reaches its minimum, and the abradability of the coating reaches its maximum. Besides, brittle fracture in the YSZ coating with high porosity is concluded to be the reason for better abradability.
PubDate: 2024-08-08
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- Influencing Factors and Process Optimization of Al/SiC Powder-cored Wires
by Plasma Transferred Wire Arc Spraying-
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Abstract: Abstract Wire thermal spraying, one of the significant coating preparation technologies in the field of thermal spraying, has the advantages of low cost, high material utilization rate and fast coating deposition. Powder-cored wires, with easily controllable compositions, are used as spraying materials to prepare functional coatings with special properties. Coatings prepared by traditional wire thermal spraying technologies, mainly including wire flame spraying (WFS), wire arc spraying (WAS) and plasma wire spraying, have some defects, such as weak bonding strength and high porosity. In this paper, the plasma transferred wire arc spraying (PTWAS) technology was innovatively proposed, by which Al/SiC powder-cored wires were successfully sprayed to deposit the aluminum (Al)/Nicalon (SiC) composite coating. Furthermore, the influences of spraying current (I), argon (Ar) flow rate (LAr), hydrogen (H2) flow rate (LH2) and other factors on Al/Sic powder-cored wires prepared by PTWAS and the optimization of the coating preparation process were mainly studied via the single factor method and the response surface methodology. After experimental exploration and analysis, the optimized process parameters were finally determined as follows: LAr was 120 L min−1, I was 160 A, LH2 was 5 L min−1, the spraying distance was 100 mm, the wire feeding speed (V) was 0.18 m s−1, and the distance between the wire and nozzle (d) was 10 mm. It was found in the test that the porosity of the optimized Al/SiC composite coating was only 1.6%, the average microhardness was 102 HV0.1, and the average bonding strength was 36.5 MPa. The comprehensive properties of this coating were better than those of the Al/SiC composite coatings prepared by WFS and WAS.
PubDate: 2024-08-07
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- Thermo-Structural Coupled Finite Element Analysis of Repair Process for
Steam Turbine Blade Using Laser-Directed Energy Deposition Method-
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Abstract: Abstract This study presents a numerical additive manufacturing simulation aimed at simulating the shape recovery process of a steam turbine blade damaged by corrosion, using laser-directed energy deposition (LDED). The simulation integrates the finite element (FE) method with heat conduction and thermo-elastoplastic constitutive equations, incorporating phase transformation. The additive manufacturing process by LDED was modeled using the death-birth algorithm, wherein a deposition layer is defined as a virtual element. Its stiffness and thermal properties activated when the laser irradiation regions overlapped. In this study, the shape of the virtual element was determined based on the cross-sectional shape of the deposition layer manufactured under various laser conditions. To validate the numerical simulation results, additive manufacturing was conducted for one pass deposition in the width direction at the center of a cantilever-supported plate made of SUS304 steel, and the changes in displacement at the free edges with respect to the process time were compared. The obtained FE results are in good agreement with the experimental results. Finally, an FE simulation was performed for the shape recovery of a steam turbine blade thinned due to corrosion damage. The results revealed that the residual stress component becomes more compressive as the laser output decreases and scanning speed increases, which is advantageous for improving the fatigue strength of steam turbine blades.
PubDate: 2024-08-06
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- Development of Tungsten Repair Technology by Atmospheric Plasma Spraying
of Tungsten and Friction Stir Processing-
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Abstract: Abstract Tungsten (W) has a high melting point, excellent thermal conductivity, and irradiation resistance, making it the most promising plasma facing material for divertors in fusion reactors, which are currently under development. However, since the divertor is exposed to an extremely harsh environment, it is considered necessary to develop suitable and cost-effective repair techniques. In this study, the applicability of the atmospheric plasma spraying (APS) method using a gas shroud as a repair technique for W components was investigated, in particular the possibility of strengthening the repaired part by applying friction stir processing (FSP) as a post-treatment. It was found that the application of a gas shroud can suppress in-flight oxidation to some extent, even when the W is deposited in air. In addition, the FSP treatment reduced grain size and porosity, resulting in an increase in microhardness of approximately 37.5% compared to the base material (W substrate) and 203.5% compared to the as-sprayed material. The gas shroud APS and FSP post-treatments have been shown to have potential as repair techniques for tungsten components in future fusion reactors.
PubDate: 2024-08-05
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- Achieving Superior Durability of Environmental Barrier Coatings through
the Use of a Modified Silicon Bond Coat-
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Abstract: Abstract The growth of a thermally grown oxide (TGO) layer has been identified as a major driving force for the failure of environmental barrier coatings (EBCs). It is always desirable to reduce the TGO growth rate in order to achieve a highly durable EBC system. In this study, an Al2O3-modified Si bond coat was developed for EBC applications. Both a Yb2Si2O7/Si baseline EBC and a Yb2Si2O7/(Si-Al2O3)-modified EBC were deposited using the air plasma spray process. The TGO growth behavior and cycling life of the EBCs were evaluated at 1316 °C in a 90% H2O (g) + 10% air environment. The TGO growth rate in the baseline EBC is over four times faster than that of the modified EBC. The modified EBC survived 1000 cycles of steam testing without failure, while the baseline EBC has an average life of 576 cycles under identical conditions. The superior durability of the modified EBC can be attributed to the significantly reduced TGO growth rate.
PubDate: 2024-08-05
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- Process Optimization of Ni60A Coating Preparation by Plasma
Spraying-Cladding Technique-
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Abstract: Abstract Ni60A spraying-cladding coatings were innovatively prepared on the surface of the Q235 steel substrate by plasma spraying-cladding technique. Ni60A powder with a particle size of 30 μm was further selected as the optimum spraying-cladding powder based on preliminary numerical simulation. The spraying-cladding distanceØ was optimized, and the optimum distance was determined as 18 and 16 mm, respectively, for the internal feeding process and external feeding process. The microhardness of the spraying-cladding coating could reach 875.6 HV during the internal feeding process at a spraying-cladding distance of 18 mm, and reach 791.6 HV during the external feeding process at a spraying-cladding distance of 16 mm. Meanwhile, the thermal effect of the plasma spraying-cladding technique on the Q235 steel substrate was less.
PubDate: 2024-07-29
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- Journal of Thermal Spray Technology Volume 32 Best Paper Awards
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PubDate: 2024-07-24
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- Effect of Nano-Fly Ash Additive on the Mechanical and Microstructural
Properties of Plasma-Sprayed Mullite Coatings-
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Abstract: Abstract The effect of MCrAlY and nano-fly ash additive powders on the mechanical and microstructural properties of mullite coatings was examined in this work. Three distinct mullite-based coatings, namely M (100% mullite), MM (95% mullite − 5% MCrAlY), and MMF (90% mullite − 5% MCrAlY − 5% nano-fly ash), were deposited onto a martensitic stainless steel (AISI 410) substrate through air-plasma spraying. MMF coatings achieved the best coating integrity during the experimental trials, with a porosity of 7.65%, and an optimum fracture toughness of 1.40 MPa m0.5. The results revealed that incorporating MCrAlY particles into mullite coatings resulted in an optimal hardness of 638 HV1. The addition of nano-fly ash significantly increased the adherence of MMF coatings to the AISI 410 substrate, which is critical to their durability and efficacy. Furthermore, the MMF coatings demonstrated a remarkable 60% reduction in crystallite size, yielding a finer size of 47 nm. Furthermore, dislocation density increased by 125%, reaching 44.8 × 10−5 nm−2, compared to MM coatings. It was also revealed that the presence of MCrAlY and fly ash nanoparticles increased shear resistance by restricting the mobility of the shear plane, obtaining the highest adhesion strength of 76 MPa. These findings show that combining MCrAlY particles with nano-fly ash in mullite coatings provides various benefits, including enhanced hardness, crystal characteristics, adhesion, and shear resistance.
PubDate: 2024-07-24
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- Study on Combustion Characteristics and Flame Flow Behavior with
Ethanol-Kerosene Mixed Fuel in HVOF Spraying-
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Abstract: Abstract Aviation kerosene is a high-density, high-calorific value fuel widely used in high-velocity oxygen fuel (HVOF) thermal spraying. However, incomplete combustion of aviation kerosene generates CO2, CO, and unburned hydrocarbons, which are not conducive to sustainable development for industry. Research on new HVOF processes using clean fuels is significant for energy conservation and emission reduction. In this study, a two-dimensional numerical model of JP-8000 spray gun flow field was established based on the computational fluid dynamics method, and the ethanol was blended into aviation kerosene fuel to reduce carbon emissions during spraying. Ethanol-kerosene premixed fuel and WC-12Co particles were injected into spray gun in discrete phase form. The KHRT method and O 'Rourke method in the discrete phase model were used to deal with the breakup and coalescence of fuel droplets. Lagrange tracking method was used to capture the flight trajectory of fuel droplets and sprayed particles, and the gas–liquid–solid coupling calculation of spraying flow field was realized. The results show that adding ethanol to aviation kerosene fuel can effectively reduce CO2 emissions. When the ethanol proportion is 10%, CO2 emissions decrease by nearly 30%. Ethanol pyrolysis leads to a slight increase in CO emissions, which can be effectively reduced by appropriately increasing the oxygen/fuel ratio. This study provides an important theoretical basis for the spraying practice of HVOF mixed fuel for energy saving and environmental protection and offers new insights for further optimizing the spraying process.
PubDate: 2024-07-22
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- Effects of Laser Shock Peening on Interfacial Bonding Strength of
Cold-Sprayed Coating-
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Abstract: Abstract 7-Series aluminum (Al) alloys have been widely used in aircraft and high-speed train manufacturing owing to its excellent mechanical properties and fracture toughness. However, surface problems of corrosion, wear and fatigue failure of Al alloy parts seriously affect the service life. In the present study, the noncontact laser shock peening (LSP) was applied to improve the fatigue life of the substrate before the coating deposited by cold spraying (CS). The effect of LSP on the interfacial bonding behavior between CS Al with 50 vol.% Al2O3 composite coatings and 7075 Al alloy substrate was comprehensively investigated. Results showed that after LSP treatment, the tensile strength is reduced from 47 to 34 MPa and 32 MPa when the laser shock energy was 2 and 3 J, respectively. Under the condition of shear strength, it decreases from 41.5 to 30 MPa and 26 MPa, respectively. In addition, numerical simulations were conducted on LSP and CS processes, and the results showed that with the increase of laser shock energy, the plastic deformation dissipation energy of Al particles increases gradually, while the plastic deformation dissipation energy of the matrix decreased. Therefore, the surface hardening caused by LSP treatment is the main reason for the decrease of interfacial bonding strength.
PubDate: 2024-07-19
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- Scanning Acoustic Microscopy Characterization of Cold-Sprayed Coatings
Deposited on Grooved Substrates-
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Abstract: Abstract The effect of non-planar substrate surface on homogeneity and quality of cold-sprayed (CS) deposits was studied by scanning acoustic microscopy (SAM). Fe coatings were cold-sprayed onto Al substrates containing artificially introduced grooves of square- and trapezoid-shaped geometries, with flat or cylindrical bottoms. The Al substrates were either wrought or cold-sprayed, to comprehend their prospective influence on the Fe coatings buildup. SAM was then used to assess morphological properties of the materials from the cross-view and top-view directions. The microstructure below the surface of the studied samples was visualized by measuring the amplitudes of the reflection echoes and the velocity of the ultrasonic waves. The SAM analysis revealed that the regions of coating imperfections around the grooves are larger than what is suggested by standard scanning electron microscopy (SEM) observations. Furthermore, we found that the seemingly non-influenced coating regions that appear perfectly homogeneous and dense in SEM do, in fact, possess heterogeneous microstructure associated with the individual CS nozzle passes.
PubDate: 2024-07-16
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