bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Dynamics Simulations of Titanium Dioxide as Model System for Size Effects in Aerosol Deposition
Authors: Daneshian Bahman , Gaertner Frank , Weber Wolfgang , Klassen Thomas , Assadi Hamid , Hoeche Daniel 
Published: September 2021

Abstract
Up to now, the role of particle sizes on deformation features of ceramic particles in aerosol deposition (AD), is not fully understood. For distinguishing general features, two-dimensional molecular dynamics (MD) simulations are applied to study associated phenomena. The nanoparticles are assumed to have original sizes of 10-300 nm and to impact the substrate at velocities of 100-800 m/s. The applied Lennard-Jones potential for the modelled nanoparticles were adjusted to mimic the mechanical properties of TiO2-anatase. For small particles, the simulations reveal three different impact behaviors of (i) rebounding, (ii) bonding and (iii) fragmentation based on initial size and impact velocity, whereas, the larger ones do not show the bonding behavior. The upper limit of the bonding regime shrinks with increasing particle sizes, the field then diminishing for the largest ones. The different impact phenomena were analyzed by evolution of the stress, strain and temperature fields. Stress and strain field results showed that “localized inelastic deformation” occurred at particle sites spreading from the interface to the substrate to the particle core. Calculated temperature fields show a local rise of around 1200 Kelvin due to the inelastic deformation, which is probably sufficient for thermal activation of further deformation features.
Predicted Anode Arc Attachment by Local Thermodynamic Equilibrium (LTE) and Two-Temperature Arc Models in a Cascaded-Anode dc Plasma Spray Torch
Authors: Zhukovskii Rodion , Chazelas Christophe , Rat Vincent , Vardelle Armelle , Molz Ron 
Published: September 2021

Abstract
Anode erosion is a common concern in dc plasma spray torches. It depends largely on the heat flux brought by the arc and the dimensions, residence time, and mode of the arc attachment to a given location on the anode wall. This paper compares anode arc attachment modes predicted by LTE (local thermodynamic equilibrium) and 2-T (two-temperature) arc models that include the electrodes in the computational domain. The analysis is based on a commercial cascaded-anode plasma torch operated at high current (500 A) and low gas flow rate (60 NLPM of argon). It shows that the LTE model predicted a constricted anode arc attachment that moves on the anode ring while the 2-T model predicted a diffuse and steady arc attachment. The comparison between the predicted and measured arc voltage indicated that the 2-T prediction is closer to the actual voltage. A post-mortem observation of a new anode ring on a plasma torch operated under the same conditions confirmed the diffuse arc attachment predicted by the 2-T arc model.
3D Microstructure-Based FE Simulation of Cold-Sprayed Al-Al2O3 Composite Coatings under Indentation and Quasi-Static Compression
Authors: Sayahlatifi Saman , Shao Chenwei , McDonald André , Hogan James David 
Published: September 2021

Abstract
This study developed microstructure-based finite element (FE) models to investigate the behavior of cold-sprayed aluminum-alumina (Al-Al2O3) metal matrix composite (MMCs) coatings subject to indentation and quasi-static compression. Based on microstructural features (i.e., particle weight fraction, particle size, and porosity) of the MMC coatings, representative volume elements (RVEs) were generated by using Digimat software and then imported into ABAQUS/Explicit. State-of-the-art physics-based modelling approaches were incorporated into the model to account for particle cracking, interface debonding, and ductile failure of the matrix. This allowed for analysis and informing on the deformation and failure responses. The model was validated with experimental results for cold-sprayed Al-18 wt.% Al2O3, Al-34 wt.% Al2O3, and Al-46 wt.% Al2O3 metal matrix composite coatings under quasi-static compression by comparing the stress versus strain histories and observed failure mechanisms (e.g., matrix ductile failure). The results showed that the computational framework is able to capture the response of this cold-sprayed material system under compression and indentation, both qualitatively and quantitatively. The outcomes of this work have implications for extending the model to materials design and under different types of loading (e.g., erosion and fatigue).
Peridynamic Simulation of Particles Impact and Interfacial Bonding in Cold Spray Process
Authors: Ren Baihua , Song Jun 
Published: September 2021

Abstract
Recently, cold spray (CS) technology has attracted extensive interest as an alternative to thermal spray methods to build a coating, which uses high kinetic energy solid particles to impact and adhere to the substrate. To date, numerous numerical studies have been carried out to investigate the deposition processes and associated mechanisms during multiple particle impact in CS. However, in the commonly used numerical techniques, the individual powder particles are often treated separately from one another, thus fail to properly consider the adhesion mechanisms during deposition. In this study, we propose a new numerical approach on base of peridynamics (PD), which incorporates interfacial interactions as a part of constitutive model to capture deformation, bonding and rebound of impacting particles in one unified framework. Two models are proposed to characterize the adhesive contacts: a) a long-range Lenard-Johns type potential that reproduce the mode I fracture energy by suitable calibrations, and b) a force - stretch relation of interface directly derived from the bulk materials mode I fracture simulations. The particle deformation behavior modeled by the peridynamic method compares well with the benchmark finite element method results, which indicates the applicability of the peridynamic model for CS simulation. Furthermore, it is shown that the adhesive contact models can accurately describe interfacial bonding between the powder particles and substrate.
Numerical Simulation of Solid Ti6AI4V Particles Impinging on a Stainless-Steel Substrate at High Speed: Influence of the Particle Temperature
Authors: Khamsepour P. , Moreau C. , Dolatabadi A. 
Published: September 2021

Abstract
Additive manufacturing processes have been used to produce or repair components in different industry sectors like aerospace, automotive, and biomedical. In these processes, a part can be built by either melted particles as in selective laser melting (SLM) or solid-state particles as in the cold spray process. The cold spray has gained significant attention due to its potential for high deposition rate and nearly zero oxidation. However, the main concern associated with using the cold spray is the level of porosity in as-fabricated samples, altering their mechanical properties. These pores are primarily found in the regions where adiabatic shear instability does not occur. It is worth noting that the deformation of the impacted solid particle plays a vital role in reaching the shear instability. Therefore, for investigating the adiabatic shear instability region, an elastic-plastic simulation approach has been used. For this purpose, it is assumed that an elevated temperature solid Ti6Al4V particle impacts on a stainless-steel substrate surface at high velocity. The results show that increasing particle temperature will significantly enhance particle deformation because of thermal softening. Additionally, they illustrate that a material jet responsible for producing a bonding between particle and substrate by ejecting the broken oxide layer will be formed when the particle has a temperature above 1073 K and substrate remains at room temperature. In the end, it should be noted that increasing particle temperature up to 723 K will not have a significant effect on substrate deformation and final substrate temperature.
Novel Strategy for Developing Bulk-Like Dense Metallic Coatings by Plasma Spraying
Authors: Li Chang-Jiu , Dong Xin-Yuan , Zhang Li , Zhu Yong-Sheng , Zhou Zhe , Luo Xiao-Tao , Li Cheng-Xin 
Published: September 2021

Abstract
Thermal spray coatings are widely used to protect materials from corrosion, wear, and oxidation, but they have yet to reach their full potential because of porosity limitations and the detrimental effects of oxidation on interlamellar bonding. This paper investigates an atmospheric plasma spraying process that deposits oxide-free dense metallic coatings with well bonded lamellae. The process produces ultrahigh temperature metallic droplets, up to 2650 °C, using specially designed powders that are deoxidized in-flight through the evaporation or gasification of oxides. The impact of these oxide-free ultrahigh temperature droplets has a spreading-fusing, self-metallurgical bonding effect resulting in fully dense bulk-like metallic coatings. Various coating materials, including NiCrMo, 304SS-Mo, NiCrBSi, and Al, are investigated, demonstrating the versatility of the new technique.
Durability of Lubricated Icephobic Coatings under Multiple Icing/Deicing Cycles
Authors: Donadei Valentina , Koivuluoto Heli , Sarlin Essi , Vuoristo Petri 
Published: September 2021

Abstract
In subzero conditions, atmospheric ice naturally accretes on surfaces in outdoor environments. This accretion can compromise the operational performance of several industrial applications, such as wind turbines, power lines, aviation, and maritime transport. To effectively prevent icing problems, the development of durable icephobic coating solutions is strongly needed. Here, the durability of lubricated icephobic coatings was studied under repeated icing/deicing cycles. Lubricated coatings were produced in one-step by flame spraying with hybrid feedstock injection. The coating icephobicity was investigated by accreting ice from supercooled microdroplets using an icing wind tunnel. The ice adhesion strength was evaluated by a centrifugal ice adhesion tester. The icing performance was investigated over four icing/deicing cycles. Surface properties of coatings, such as morphology, topography, chemical composition and wettability, were analyzed before and after the cycles. The results showed an increase in ice adhesion over the cycles, while a stable icephobic behaviour was retained for one selected coating. Moreover, consecutive ice detachment caused a surface roughness increase. This promotes the formation of mechanical interlocking with ice, thus justifying the increased ice adhesion. Finally, the coating hydrophobicity mainly decreased as a consequence of the damaged surface topography. In summary, lubricated coatings retained a good icephobic level after the cycles, thus demonstrating their potential for icephobic applications.
Next Generation Axial III Torch
Authors: Kamble Ash 
Published: September 2021

Abstract
The Axial III, launched in 1994, is a patented plasma spray torch with axial injection of feedstock. In comparison to the traditional radial injection, axial injection technology has proven to offer greater deposition efficiency, throughput, and cost savings on numerous applications [1]. Despite these benefits, the original Axial III M600 torch had several limitations due to its size, mass, and number of components. To address these shortcomings, a smaller, lighter, and more ergonomic version of the torch was developed, called the Axial III Plus, that produces the same high-quality coatings at high feed rates and deposition efficiency. This paper highlights the innovations in this new torch and the potential applications it opens for the plasma spraying industry.
Suspension Spraying Tip: High Molecular Weight Solvent
Authors: Cizek Jan , Musalek Radek , Medricky Jan , Tesar Tomas , Lukac Frantisek , Chraska Tomas , Dukovsky Daniel 
Published: September 2021

Abstract
In suspension spraying, the two most frequently used solvents are water and ethanol. In this study, we test a potential alternative, a high-molecular weight solvent. Two organic solvents are compared: ethanol (serving as a benchmark, suspension formulated at 10 wt.% solid load) and di-propylene glycol methyl ether (two suspensions at 10 wt.% and 20 wt.%). Submicron alpha-alumina powder is used as a model material to formulate the suspensions. It is shown that ethanol- and ether-based-feedstock coatings are fully comparable in terms of their microstructure, porosity content, surface roughness, and hardness. However, the ether-based coatings exhibit slightly higher levels of α-Al2O3 phase than their ethanol-based counterpart (17 wt.% vs. 6 wt.%). The use of 20 wt.% solid load in the ether solvent leads to a twofold increase in the deposition rate while, as opposed to ethanol, successfully retaining a dense microstructure. Ether also costs less than ethanol and is safer to handle.
Development of 45S5/PEEK Bioactive Coatings by Cold Gas Spray for Orthopedic Implants
Authors: Garrido B. , Albaladejo-Fuentes V. , Cano I.G. , Dosta S. 
Published: September 2021

Abstract
Cold Gas Spray (CGS) technology has allowed the development of biofunctional composite coatings composed of 45S5 and Polyetheretherketone (PEEK). The combination of a bioactive glass material embedded in a biocompatible polymeric matrix becomes this new composite in an interesting material for orthopedic applications since meet the biomechanical and biological requirements of an artificial implant. In the present study, blends of bioactive glass 45S5 and PEEK powder with different granulometry and 45S5/PEEK ratio have been prepared. These mixtures of powders have been deposited onto PEEK substrates by CGS with the goal of incorporating a bioactive additive to the biocompatible polymer, which can improve the bone-implant interaction of PEEK. The deposition efficiency (DE) and thickness of the coatings have been evaluated and from the results obtained, it was possible to conclude that DE and coating thickness are significantly affected by the granulometry and by the 45S5/PEEK ratio of the blends. By Scanning Electron Microscopy (SEM) inspection, it was observed that the use of blends with high 45S5/PEEK ratio led to the deposition of coatings with high content of 45S5 particles embedded in the polymeric matrix. Finally, the friction behavior of the coatings was analyzed performing ball-on-disk tests and these experiments showed that the presence of glass particles has a beneficial role in the wear resistance of the coatings.
Tribological Properties of Cold Gas Spraying FeMnCrSi Alloy
Authors: Vaz Rodolpho F. , Dosta Sergi , Cano Irene G. , Pukasiewicz Anderson G.M. 
Published: September 2021

Abstract
FeMnCrSi and 316L alloy coatings were deposited on carbon steel substrates via high-pressure cold gas spraying and their microstructure, hardness, and wear resistance were obtained. Ball-on-disk testing (ASTM G99) was used to measure sliding wear behaviors. The mechanism of wear was found to be the same for both coatings, although FeMnCrSi had a higher coefficient of friction while 316L had less volume loss.
Cold Spray Process to Mitigate Potential Stress-Corrosion Cracking in Used Nuclear Fuel Storage Canisters
Authors: Pocquette Nicholas , Yeom Hwasung , Agiwal Hemant , Pfefferkorn Frank , Sridharan Kumar , Ross Kenneth , Kessler John , Cannel Gary 
Published: September 2021

Abstract
Cold spray deposition is being investigated for mitigation of chloride-induced stress corrosion cracking (CISCC) in dry cask storage systems (DCSS) for spent nuclear fuel. Welded regions of austenitic stainless-steel canisters in DCSS are under tensile stress and susceptible to environmental chloride corrosion, which can potentially lead to the formation of CISCC. The low thermal input and high throughput nature of cold spraying make it a viable repair and mitigation option for managing potential CISCC. Cold spray coatings are under compressive stress and act as a barrier in Cl-rich environments. Characterization data including microstructure, hardness, and corrosion resistance are presented for cold spray coatings on stainless steel substrates.
Emissions from Metallic Powder and High Energy-Based Process – Thermal Spraying, Powder Atomization, and Additive Manufacturing – Knowledge Refresh
Authors: Darut G. , Dieu S. , Schnuriger B. , Vignes A. , Bihan O. Le , Morgeneyer M. , Lezzier F. , Devestel F. , Vion A. , Berguery C. , Roquette J. 
Published: September 2021

Abstract
This paper addresses a need for information on nanoparticle emissions and related issues such as worker exposure, filtration efficiency, and dustiness. A survey has been conducted on the working conditions and safety measures used in thermal spray companies and the results compared to scientific literature and previous surveys. Responses to questions on matters of health and safety reveal a lack of information and awareness of the risks posed by the emissions of ultrafine particles generated by thermal spraying processes.
Method for Identifying In-Flight Particles based on Digital Image Technologies in Thermal Spraying
Authors: Yao Yijun , Liu Shaowu , Planche Marie-Pierre , Deng Sihao , Liao Hanlin 
Published: September 2021

Abstract
In thermal spray processes, the characteristics of in-flight particles (velocity and temperature) have a significant effect on coating performance. Although many imaging systems and algorithms have been developed for identifying and tracking in-flight particles, most are limited in terms of accuracy. One key to solving the tracking problem is to get an algorithm that can distinguish different particles in each image frame. As the study showed, when noise and interference are treated, particles are more readily identified in the background, leading to more accurate size and position measurements with respect to time. This approach is demonstrated and the results discussed.
A New One-Step Deposition Approach for a Low Friction Graphene Nanoflakes Coating
Authors: Aissou Taki , Veilleux Jocelyn , Braidy Nadi 
Published: September 2021

Abstract
Recent studies have shown that graphene can improve the tribological performance of materials by lowering the coefficient of friction and increasing wear resistance. In this present work, the authors evaluate an inductively coupled plasma process that synthesizes graphene nanoflakes in-flight and uniformly deposits them on metallic substrates. The quality of the graphene flakes was characterized and coating surface friction was measured using a ball-on-three-plates tribometer. Test results showed that graphene nanoflake coatings reduced the coefficient of friction of steel from 0.6 to less than 0.2.
Characterization of Lithium Phosphate Deposit by Atmospheric Plasma Spraying
Authors: Sun Yin-Qiu , Wei Zheng , Luo Xiao-Tao , Li Chang-Jiu 
Published: September 2021

Abstract
Plasma spraying was used to deposit Li3PO4 coatings from sintered dense powders in three size ranges to study the effects of particle size and spraying distance. Coating microstructure, crystal structure, and composition were characterized using SEM, XRD, ICP-MS, and FTIR. It was found that sintered dense powders have a high temperature orthorhombic phase (γ-Li3PO4) that differs from the β-Li3PO4 phase associated with agglomerated Li3PO4. Plasma-sprayed coatings produced from these powders have similarly dense microstructures with fracture-surface morphology like that of sintered bulk. The effect of particle size and spraying distance on atomic ratio is also investigated in the study.
Effect of Ceramic Particle Reinforcement on the Erosion Resistance of Thermally Sprayed De-Icing Systems
Authors: Dehaghani Shahed Taghian , McDonald André , Dolatabadi Ali 
Published: September 2021

Abstract
Developing effective heating systems to prevent ice accretion on the surface of wind turbine blades and aircraft wings is of great significance for extreme cold environments. However, due to high velocity impingement of water droplets and solid particles on the surface of these components, an appreciable degree of surface material degradation may occur. In this study, nickel-chromium-aluminum-yttrium (NiCrAlY) was chosen as a metal matrix material for a coating-based heating system. Pure ceramic powders, namely, alumina and titania, and a cermet powder, tungsten carbide-cobalt (WC-12Co), were mechanically admixed with NiCrAlY powder and deposited to fabricate reinforced metal matrix composite (MMC) coatings. The powders were deposited on cylindrical low carbon steel bars by using flame spraying. The specimens were placed in a wind tunnel to conduct a comparative investigation of their erosive wear resistance under water droplet impact. A cold spraying unit was used for solid particle impact erosion tests. The erosive wear rates were quantified by measuring mass loss. The experimentally obtained results showed noticeably lower wear rate in NiCrAlY-WC-12Co and NiCrAlY-titania coatings compared to the other coatings. The results suggest that certain MMC coatings could be effectively employed to decrease the erosion rate of coating-based heating elements.
Microstructure of Atmospheric Plasma Sprayed (Al,Cr)2O3-TiO2 Coatings from Blends
Authors: Grimm Maximilian , Drehmann Rico , Lampke Thomas , Conze Susan , Berger Lutz-Michael 
Published: September 2021

Abstract
This study investigates the microstructure and hardness of coatings produced by atmospheric plasma spraying using a commercial (Al,Cr)2O3 solid solution (ss) powder blended with various amounts of TiO2. The microstructures were analyzed using SEM, EDS, and XRD measurements. It was shown that blending with TiO2 reduces porosity and defect density while increasing deposition efficiency and microhardness. Small amounts of Ti in ss (Al,Cr)2O3 splats were detected in coatings prepared from blends with higher TiO2 content. Variations in aluminum and chromium content were also observed.