bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Coating Thickness on the Stress Distribution in Hip Implants
Authors: Wang W.-Z. , Han P. , Tu S.-T. , Wang L.-B. , Xuan F.-Z. 
Published: January 2023

Abstract
Effect of different thickness of bio-medical coatings on the bone stress distribution near the hip implant- bone interface is very important factors for the bio-coated implant design and clinical application. However, in the traditional finite element analysis, the muscle forces have not been considered, which results in a difference between the original analysis models from the actual condition. In this study, the hip contact forces, as well as the associated muscle forces are imposed. Wollastonite coatings and titanium alloy (Ti6Al4V) for implants are used in the model, which is constructed through using SolidWorks software. The bone and coating stress distributions near the hip implant coated with different thickness from 50 to 250 µm are calculated and analyzed by means of finite element analysis by ANSYS WORKBENCH Software. After hip replacement, the von Mises stress distribution is similar to that before the total hip arthroplasty, whereas the corresponding results decrease obviously. Effect of coating thickness has an indistinct influence on the bone stress near the hip implant.
Wire Arc Spray Copper Coatings in Medical Applications
Authors: Ahmadian O. Sharif , Jazi H. Salimi , Fathi M. H. , Mostaghimi J. , Pershin L. 
Published: January 2023

Abstract
Infection of medical devices and treatment rooms can cause significant morbidity and mortality. Having antibacterial surfaces such as silver and copper coated areas reduces the risk of bacteria growth considerably. In the current study, wire arc spraying technique has been utilized to produce an ultra fine microstructure Antibacterial copper coating on stainless steel substrate. The chemical composition, microstructure, and surface morphology of copper coatings were characterized with X-ray diffraction (XRD) and scanning electron microscope. Determination of thickness and adhesion of the coating were investigated. The antibacterial property of copper coatings was analyzed by both gram negative Escherichia coli NCTC 10418 and gram positive Staphylococcus aureus NCTC 11047. The antibacterial performance of coatings was compared to stainless steel 316 and a micro grain structure of the commercially available copper. Results indicated that as-sprayed copper coatings have an excellent antibacterial behavior compared to stainless steel and micro grain copper which can be contributed to the fine grain size and existing of defects and micro pores in the microstructure.
Advanced Image Processing of Ag-Based Composite Powders for the Modeling of the Cold Spray Process
Authors: Zeralli Y. , Proudhon H. , N’Guyen F. , Jeandin M. , Lenoir N. , Doublet L. 
Published: January 2023

Abstract
Cold spray can substitute for several coating processes for various applications, due to a high efficiency coupled with high properties for the sprayed product. The use of a composite powder rather than a powder blend was shown to be beneficial, especially for the cold spray of electrical contacts. The objective of this work is to optimize a composite powder (Ag-14wt% SnO2) using numerical simulation of the deformation of the particle at the impact onto the substrate (Cu). Every elementary composite particle was made of an agglomerate of Ag and SnO2 smaller particles, which exhibited more or less porosity depending on the powder processing conditions. The first step was to study the distribution of these various constituting phases plus porosity. Three types of powders which showed different phases and porosity characteristics deliberately were developed. Three-dimensional images of the agglomerate were acquired using microtomography which exhibited the porosity network well in the dual-phased particle material. These actual 3D images were used to feed a simulation of the impingement of a particulate agglomerate to result in a splat onto the substrate. For this, a two dimensional deformation model was developed on the route to a three-dimensional model which is expected to be more powerful. The influence of agglomerate characteristics, primarily porosity, on the deformation behavior was studied. Consequences on splat-substrate adhesion and deposition efficiency could therefore be investigated in the light of direct observation of the cold-sprayed material.
Deposition Behavior and Microstructural Features of Vacuum Kinetic Sprayed AlN
Authors: Park H. , Heo J. , Fei Cao , Kwon J. , Kang K. , Bae G. , Lee C. 
Published: January 2023

Abstract
Vacuum kinetic spray (VKS) technology was employed to fabricate AlN films. In order to investigate the relationship between the deposition behavior with change of the size and microstructure of feedstock, AlN powders were pre-treated through ball-milling and heat-treatment. It is observed that the particle size decreased and defect density increased after the ball-milling. After the heat-treatment of the ball-milled powder, on the other hand, the particle size was not changed significantly, while the defect density was reduced by recovery. The coatings of ball-milled and heat-treated powder were obviously thicker than that of only ball-milled powder. It is inferred that, during the heat-treatment, although the defects were reduced by recovery, the dislocations were aligned, through which the cracks were able to propagate more easily. By the combined effects of ball-milling and heat-treatment, more fragmentations with new surfaces of the particles were generated during VKS, which would improve the deposition efficiency. Therefore, in VKS process, the deposition behavior is shown to be affected by not only particle size, but also the defect density and microstructure of the feedstock powder.
Comparisons of Two Models for the Simulation of a DC Arc Plasma Torch
Authors: Huang Renzhong , Fukanuma Hirotaka , Uesugi Yoshihiko , Tanaka Yasunori 
Published: January 2023

Abstract
The hypothesis of local thermal equilibrium (LTE) in thermal plasma has been widely accepted. Most of the simulation models for the arc plasma torch are based on the hypothesis of LTE and its results indicate a good validity to mimic the pattern of the plasma flow inside the plasma torch. However, due to the LTE hypothesis, the electrical conductivity near the electrodes is significantly low because of the lower gas temperature. Consequently, it is difficult for the flow of electrical current to pass between the anode and cathode. Therefore, a key subject for a model depending on the LTE assumption is to deal with the low electrical conductivity near the electrodes. In this study, two models, determining the electrical conductivity at the vicinity of the electrodes with two different assumptions, were employed to calculate the flow patterns inside a non-transferred DC arc plasma torch. A comparison of the gas temperature, velocity, voltage drop and the heat energy of the plasma arc between the two models were carried out. The results indicate that plasma arc inside the plasma torch fluctuates as simulated by both of the two models. It seems that the model can obtain comparable accuracy compared with the experimental results if the plasma gas electrical conductivity is determined by a nominal electron temperature.
HVOF Process Control Enabling Strategies
Authors: Ghabchi A. , Varis T. , Holmberg K. , Sampath S. , Varis T. , Holmberg K. , Sampath S. 
Published: January 2023

Abstract
Complexity in dynamics and mechanism of supersonic flame formation and effects of processing variables has made the understanding of interaction of particles and flame a difficult task. Lack of such understanding limits the possibilities of controlling the process to obtain desired in-flight particles temperature and velocity and consequent particles state. This problem is even more pronounced in TS systems with no dedicated decoupled temperature and velocity controlled regime. Different approaches based on total volume flow, back pressure and fuel to oxygen ratio have been examined to address the robustness of each approach to control the temperature and velocity. WC-CoCr material was used employing DJ-2600 torch. A guideline to control the in-flight particles temperature and velocity based on process variables is provided. A process map was developed to establish a correlation between process, in-flight particles state, microstructure, properties and performance.
Kinetic Metallization of Ceramic Armor Tiles
Authors: Tapphorn R. , Gabel H. , Premuda L. , Crowe T. , Hashimoto K. 
Published: January 2023

Abstract
Ceramic tiles are widely used as ballistic armor due to their ability to absorb high specific impact energy. However, ceramic materials often exhibit very low ductility and have a tendency to exhibit multiple fractures in spider-web patterns around the point of impact. One method used to introduce ductility is to encapsulate the tile in a metal jacket, or to provide a strongly adhered metallic backing plate. Aluminum and titanium metals are of primary interest to decrease the overall weight of the armor material system. The low temperature Kinetic Metallization (KM) process allows direct deposition of the metals onto the ceramic tiles. This is not possible with thermal spray processes due to the extreme mismatch in thermal expansion and adverse metallic-ceramic chemical reactions at high temperatures. Kinetic Metallization has been used to deposit aluminum and titanium coatings onto silicon carbide (SiC) and proprietary ceramic matrix composite (CMC) tiles. Ballistic testing of coated tiles has shown decreased fracturing of the armor material, leading to improved performance for subsequent impacts.
Kinetic Metallization Repair of Ion Vapor Deposited Aluminum Coatings
Authors: Tapphorn R. , Gabel H. , Hashimoto K. , Crowe T. 
Published: January 2023

Abstract
The repair of damaged Ion Vapor Deposition Aluminum coatings on high strength steel aircraft components has generally required the use of brush plating with hazardous materials including cadmium. Inovati has developed a unique Al-Trans (aluminum-transition metal) coating using the Kinetic Metallization process that permits repairs of IVD-Al coatings on high strength steels. Originally the Al-Trans coating formulation was developed for commercial application on telecommunication equipment steel racks as an electrically conductive grounding strip with excellent corrosion resistance. Recent research was completed with NAVAIR to further develop this coating formulation and the Kinetic Metallization process for repair of IVD-Al coatings on aircraft components. This presentation will describe the KM repair process and the tests completed to qualify the repaired coatings. Inovati has recently developed a KM-Mobile Coating System with a handheld Spray Gun for the field repair of corrosion damaged magnesium and aluminum alloy aircraft components.
High Velocity Air-Fuel Spraying and Its Applications in Oil and Gas Industry
Authors: Verstak A. , Kusinski G. 
Published: January 2023

Abstract
Recent developments of High-Velocity Air-Fuel (HVAF) spraying and blasting focused on a substantial increase of spray particles velocity. The efforts further improved coating quality, allowing deposition of metallic and carbide-base coatings non-permeable to gas at thickness as low as 40-50 micron. The coatings demonstrate low dissolved oxygen content, a favorable combination of high hardness and toughness. Coupled with the enhanced technological efficiency of modern HVAF equipment, this initiated not only the acceptance of HVAF technologies in established thermal spray markets in the oil and gas industry, but also the development and successful implementation of new coating applications. The examples are wear and corrosion resistant tungsten carbide-based coatings on hydraulics rods of dock cranes, corrosion resistant Ni-Cr-Mo-type coatings on vessels of sulfur removal equipment, tungsten carbide coatings on restriction grid plates and slide gates of catalyst towers, high-temperature erosion resistant chromium carbide- based coatings on thermowells and valve stems, wear and cavitation resistant Co-Cr-W-C-type and carbide coatings on housing wear rings and impeller hubs of high-temperature pumps.
Oxidation Behavior of TiAl3-Al Composite Coating on γ-TiAl Based Alloy at 950 °C
Authors: Yang J. , Kong L. , Cui X. , Tao Y. , Li T. , Xiong T. 
Published: January 2023

Abstract
TiAl3-Al composite coating on γ-TiAl alloy was prepared by cold spray and subsequent heat-treatment. The Oxidation test, which was carried out at 950 °C in air, indicated that the bare alloy exhibited poor oxidation resistance, significant weight loss was observed after oxidation for 70 h. The oxides formed were the mixture of TiO2 /Al2O3. For the specimen with the TiAl3–Al coating, great improvement in oxidation resistance was observed. Approximate parabolic oxidation kinetics was observed for the oxidation period. The microstructure analysis showed a dense TiAl2 interlayer and a reticular Cr rich phase formed between the composite coating and the substrate. The oxides in the oxidized coating were mainly alumina, with only trace of titanium dioxide and titanium nitrides after oxidation up to 1000 h. A certain amount of TiAl3 phase in the coating remained unoxidized and unconsumed. The EPMA analyses of the coated samples showed that no trend of oxygen or nitride diffusion into the substrate and no oxide formed beneath the TiAl2 interlayer.
Bonding Mechanism in Cold-Sprayed Aluminum Coatings: Localized Interatomic Bonds
Authors: Zhang Yinyin , Zhang Jishan 
Published: January 2023

Abstract
It has been widely demonstrated that the bonding between particles in cold-sprayed coatings results from impact-induced extensive deformation in the interfacial area. However, the mechanism of bonding remains obscure. This present work provides theoretical and experimental evidence of localized interatomic bonds between particles. The chemical bonding energy differences between Me-O (bonding energy of metallic and oxygen atoms) and Me-Me (bonding energy of metallic atoms) indicate a preferential trend of breaking down of Me-Me bonds and therefore a new interatomic bond was established. This hypothesis is addressed in terms of dynamics based on data generated by numerical modeling. In addition, interfacial regions of cold-sprayed nanocrystalline composite coatings were observed by TEM. The results revealed that whether or not recrystallization occurred in these places was determined by development of metallic bonding between particles.
A Comparison of Thermal Shock Behavior between APS and Low-Energy VLPPS ZrO2-7%Y2O3 Thermal Barrier Coatings
Authors: Zhu L. , Bolot R. , Planche M.P. , Liao H. , Coddet C. , Zhang N. 
Published: January 2023

Abstract
Yttria-stabilized zirconia (YSZ) coatings have been frequently used as a thermal protective layer on the metal or alloy component surfaces. In the present study, ZrO2-7%Y2O3 thermal barrier coatings (TBCs) were successfully deposited by DC (direct current) plasma spray process under very low pressure condition (less than 1 mbar) using low-energy plasma guns F4-VB and F100. The experiments were performed to evaluate the thermal shock resistance of the different TBC specimens which were heated to 1373 K at a high-temperature cycling furnace and held for 0.5 h, followed by air cooling under room temperature during 0.2 h. For comparison, the corresponding APS counterparts were also elaborated to carry out the similar experiments. The results indicated that the VLPPS coatings displayed better thermal shock resistance. Moreover, the failure mechanism of the coatings was also elucidated.
Influence of Al2O3 Content on the Microstructure and Microhardness of NiAl- Al2O3 Composites with Micro-Sized Al2O3 Strengthening Particles by Plasma Activated Sintering
Authors: Yang G.-J. , Zhao S.-N. , Li C.-X. , Li C.-J. 
Published: January 2023

Abstract
Thermal spraying may be a promising approach for the deposition of NiAl-Al2O3 composite coatings. To understand the intrinsic mechanical property of NiAl-Al2O3 composite, dense NiAl-Al2O3 composites were prepared by plasma activated sintering using the ball milled Ni/Al- Al2O3 composite powders contain both micro-sized Al2O3 strengthening particles and submicron-sized Al2O3 dispersoids homogeneously distributed in the NiAl matrix phase. The angular morphology of the Al2O3 particles in composite powder was changed to spherical or near spherical morphology after plasma activated sintering. Compared to the NiAl-Al2O3 composites with low Al2O3 content, NiAl- 60vol.%Al2O3 composite consisted of less fine submicron-sized Al2O3 dispersoids. Melting induced mechanism was proposed to explain the spheroidization and the change of Al2O3 particle size distribution. The hardness of the NiAl-Al2O3 composites with both micro-sized Al2O3 strengthening particles and submicron-sized Al2O3 dispersoids increased with the increase of Al2O3 content. The relation was employed to theoretically estimate the hardness using volume fractions of components and corresponding hardness. The estimated hardness was compared with the observed ones. It was found that bimodal sized particles reinforcement results in a higher hardness than the theoretical value, which could be attributed to the dispersion hardening effect.
Microstructure and Properties of Porous Ni50Cr50- Al2O3 Cermet Support for Solid Oxide Fuel Cells
Authors: Zhang Shan-Lin , Li Cheng-Xin , Li Chang-Jiu , Yang Guan-Jun 
Published: January 2023

Abstract
Microstructure of cermet support influences significantly the performance and stability of solid oxide fuel cells (SOFCs). The properties required for the support include high electrical conductivity, necessary permeability, good match of thermal expansion with other layers and high temperature strength. In this study, a porous Ni50Cr50-Al2O3 cermet was designed as the support of SOFC. The porous cermet was deposited by flame spraying with a powder mixture of 30%vol Al2O3 and 35%vol Ni50Cr50 and 35%vol polyester. The effect of cermet microstructure on its gas permeability was investigated. The electrical conductivity, thermal expansion coefficient and bending strength of cermet support were also studied. The results showed that the gas leakage rate of the cermet support increased with the increase of polyester content in the starting powder. The thermal expansion coefficient of the composite cermet decreased with the increase of the volume fraction of Al2O3. Moreover, the electric conductivity of the cermet increased significantly after high temperature sintering, and reached 1015 S/cm after sintering at 1000°C for 15 hours. The three point bending strength of the Ni50Cr50-based cermet support reached 171 MPa. The cermet stability at high temperatures and SOFCs performance were discussed.
Preparation and Characterization of Super-Hydrophobic Surface through Particle Deposition by Vacuum Cold Spray
Authors: Guo T. , Li C.-J. , Yang G.-J. , Li C.-X. , Qiao G.-J. 
Published: January 2023

Abstract
Super-hydrophobic materials have broad application prospects in industry, agriculture and daily life. Not only the types of the materials but also the structure and the morphology of their surface have a significant impact on the hydrophobicity of materials. In this study, nano-structured TiO2 coatings were deposited on glass surface by vacuum cold spray using agglomerated nano-TiO2 powder and aggregated nanostructured TiO2 powder to create nanostructured and micro-nano hierarchical structured TiO2 surface. The surface morphology of nanostructured TiO2 deposited surface was characterized by scanning electron microscopy and 3D laser microscopy. The influences of the surface morphology, annealing and fluoroalkylsilane adsorption treatment on the wettability of the surfaces were investigated. The results showed that the nanostructured TiO2 coatings in the as-sprayed and annealed states were hydrophilic. However, after adsorbing treatment by fluoroalkylsilane, the nanostructured TiO2 deposited glass surface exhibited super-hydrophobicity. The contact angle of water drops on TiO2 coating surfaces became greater than 120° up to 170° depending on the local surface morphology. Moreover, micro-nano hierarchical structured TiO2 coatings obtained by VCS using aggregated nano-TiO2 after fluoroalkylsilane adsorption exhibited excellent super-hydrophobic performance and the contact angle was greater than 170° and water droplets tended to roll on the surface with extremely low adhesion.
Process and Microstructure of Nano-Zirconia Coatings Prepared by Solution Plasma Spraying
Authors: Yang Hui. 
Published: January 2023

Abstract
Nanostructured zirconia coatings were prepared by solution plasma spraying. The phase composition and microstructure of the coatings and powders dried from solution were observed by XRD and SEM. Fine grained nanostructured zirconia coatings can be obtained. Nano-zirconia coatings adhered well with the substrate, and exhibited few vertical cracks.
Evaluation of Sprayed Coatings by Electrical Method
Authors: Morisawa Y. , Maruyama T. 
Published: January 2023

Abstract
A method for evaluating the adhesion of metallic thermally sprayed coatings by measuring the electrical resistance of the coating sprayed on a metal substrate was carried out. The thermal sprayed coatings were made of zinc alloy on carbon steel substrates. The electrical resistance levels between the substrates and coatings were evaluated. The electrical resistance increases with increasing measurement time. The larger the rate of increase of the electrical resistance, the lower the adhesive strength. There is a possibility to evaluate qualitatively the adhesion properties.
Implementation of a Low Cost Monitoring and Control System to a Radial Injection Plasma Spray Process Towards Manufacturing of High-Quality, Consistent Coatings at Improved Efficiency and Lower Cost
Authors: Matikainen V. , Niemi K. , Kylmälahti M. , Vuoristo P. , Larjo J. , Kriikka N. , Linden I. 
Published: January 2023

Abstract
In order to produce plasma sprayed coatings with best economical, technical and environmental qualities several factors need to be taken into consideration. These include properties of the powder feedstock, equipment reliability, optimized process parameters and stability of the spray process. In case of plasma spray guns with conventional and frequently used radial powder feeding configurations, proper and constant powder feeding during spraying plays an important role. Once optimized spray parameters need to be preserved and optimal spray conditions for best coating quality and highest deposition efficiency should also be kept constant during possible changes of the spray parameters, e.g. due to electrode wear, powder quality variations etc. Various spray process monitoring tools are available and useful for this purpose; especially if they are cost-effective to be adopted by industrial thermal sprayers. In the present work, a conventional 40 kW plasma spray process equipped with a typical radial single point powder feeding was studied with the robust and industrially viable “SprayWatch G” system with an on-line monitoring CCD camera. The plasma spray torch was run under slightly varying spray conditions typical to normal industrial spraying; the spray process was monitored, and various actions, e.g. powder carrier gas flow rate adjustment, were realized in order to restore the most optimum conditions. Special attention was paid on finding correlations between the temperature, brightness, shape, and direction of the spray plume and the properties, e.g. deposition efficiency and physical properties of the sprayed alumina coatings.