bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Microstructure and Properties of Coating Produced by High Velocity Electric Wire Arc Spraying of TiB2/Al2O3 Cored Wire
Authors: Borchers Wang , Liuying Wang , Xunjia Su , Xuetao Zhang 
Published: July 2022

Abstract
In the paper, a newly composite TiB2/Al2O3 coating prepared by High Velocity Electric Wire Arc Spraying and cored wire with ceramic powders composed of refractory Al2O3 and TiB2 filling inside was introduced. The microstructure and composition of the TiB2/Al2O3 coating were investigated by metallgraphic microscope, scanning electron microscope and X-rayed diffraction, Bonding strength and hardness and mechanics properties were tested. The experimental results show the TiB2/Al2O3 composite coating possessed high hardness and higher bonding strength with substrate and excellent comprehensive mechanical properties. It can be used for improving shoot-proof properties in the surface of arms.
Latest Case Study and Subject of Thermal Spray Technology in Japan
Authors: Tani Kazumi , Nakahira Akira 
Published: July 2022

Abstract
The currently distinctive thermal spray applications in the surface modifying technology in Japan are introduced. Applying inventive combinations of coating materials and spraying processes have developed many unique applications. In terms of thermal spraying processes, in particular, low pressure plasma spray, atmospheric plasma spray, and high velocity oxy/fuel flame spray are employed. The profiles of industrial applications that are performed mainly by coating contract job shops are presented. For the typical coating materials, alumina, and zirconia as oxides, tungsten or chromium carbide cermet as composite materials, and special alloys were selected. The performance of coatings includes wide range field such as electrical insulation, erosion resistance, corrosion, wear resistance and so on. The current status of thermal spray market in Japan is also introduced.
Present Furnace and Pot Roll Coatings and Future Development
Authors: Fukubayashi Harold H. 
Published: July 2022

Abstract
In the recent past, automotive manufacturers worldwide started to demand sheet metals with very high surface quality, particularly those used in exposed panels. In order to meet this requirement the majority of strip producers started to use thermal spray coatings of one kind of another on essentially all the rolls in annealing, galvanizing, and other processing sections. In fact, no sheet for an exposed application can be produced without the use of roll coatings. Bridle and accumulator rolls in both entrance and exit ends of a galvanizing line are usually coated with tungsten or chromium carbide and/or oxide ceramic. These coatings prevent surface damage on the roll and provide proper friction/grip. In some cases, a properly textured coating provides the desired characteristics or profile on the strip surface. Coatings for furnace and hot tension bridle rolls prevent pickup due to slippage, iron fines, or an accidental change in the furnace atmosphere. The coating on pot and stabilizer rolls in a galvanizing pot prevents not only dross adhesion but also provides high enough friction to eliminate hydroplaning. Deflector or tower rolls are also coated with carbide or ceramic to minimize zinc pickup. The coating on rolls, in general, allows smooth operation of the line and produces an improved strip surface. At the same time, it allows an extension in service life, thus reducing frequency of maintenance shutdown. This paper attempts to review the present state of the art and predict future development.
Evaluation of Adhesive Strength of HVOF Sprayed Metallic Alloy Coatings by a Modified Tensile Test
Authors: Kuroda S. , Inoue T. , Kishi A. , Yokoyama K. , Yumoto H. , Gotoh Y. 
Published: July 2022

Abstract
A new method for evaluating the tensile adhesive strength of thermal sprayed coatings has been developed using a test specimen that incorporates an artificially introduced circumferential crack to control the stress intensity factor at the crack tip along the interface between the coating and the substrate. FEM-analysis is carried out to calculate a correction factor and the stress intensity factor for the test specimen. When the results of tensile test are sorted out using the stress intensity factor at which failure occurred, constant values should be obtained regardless of changes in geometry such as crack length and the diameter of test specimen. The method was first applied to air plasma spray (APS) coatings and then to HVOF sprayed coatings. Effects of substrate preparation such as surface roughness and preheating temperature on the resultant coating adhesion were studied experimentally.
Comprehensive Study of the Process-Property Correlations: Case Study for Molybdenum Coatings
Authors: Vaidya A. , Streibl T. , Li L. , Sampath S. , Gouldstone A. , Kovarik O. , Greenlaw R. 
Published: July 2022

Abstract
Thermal spray coatings exhibit a wide variety of microstructural characteristics that lead to variation in their functional properties. A complete understanding of the plasma spray process includes examination of the particle-flame interaction, particle impact (to form the splats), and the particle-substrate interaction during coating deposition. The links between these process parameters and coating properties has been established by using diagnostic tools in conjunction with a splat collection shutter and an in-situ curvature measurement instrument. In this study, a commercial grade molybdenum (Mo) powder was plasma sprayed; the spray stream was characterized in relation to the resulting particle state. A "splat map" was deposited through a "spray stream guillotine" to capture the fingerprint of the plume cross section. Subsequently, coatings were deposited at these spray conditions on a newly developed in-situ curvature measurement instrument to measure coating stresses and to estimate the coating modulus. Splats and coatings were subsequently characterized by micro-diffraction (for splat residual stresses), by nano and micro-indentation for elastic and elastic-plastic properties, and by electron microscopy. This complete history of the process followed by splat and coating characterization provides insight into the correlation between processing parameters, resultant particle states, and final coating properties. The role of particle temperature and velocity on the splat (and coating) morphology and residual stress is explained in the results.
Strain Tolerance Characterization for HVOF Coatings using the Acoustic Emission Tool
Authors: Bouaricha S. , Legoux J.-G. 
Published: July 2022

Abstract
The crack propagation characteristics obtained by observing the microstructure of bent coatings at different stages of applied strain were conducted. At the same time, acoustic emission (AE) features of released events were recorded. Generated cracks were found to emit weak acoustic emission events at the initiation (creation) of the crack at the coating surface, and then become strong releasing a uniform acoustic emission energy per event, when propagating transversally in the coating. However, cracks propagating at the interface with the substrate could generate both weak and strong events. It was also found that increasing the thickness of the coating leads to a decrease in the number of events and an increase of their released acoustic emission energy.
Deposition Efficiency and Microhardness of Plasma Sprayed Zirconia Coatings Using Different Powders as Feedstocks
Authors: Chen Huang , Choi Chul Ho , Lee Soo Wohn , Ding Chuan Xian 
Published: July 2022

Abstract
A typical feature of plasma sprayed zirconia-based coatings is that their depostion efficiencies are low. Thus, from the economic view of reducing cost, how to improve the depostion efficiency of plasma sprayed zirconia-based coatings is very important for practical application. In this paper, spray-dried nanostructured powders and conventional powders were used as feedstocks to deposit nanostructured and conventional zirconia coatings by atmospheric plasma spraying(APS). Deposition efficiencies for both nanostructured and conventional zirconia coatings deposited under different spraying parameters were comparatively measured. The obtained results revealed that the spray-dried nanostructured powders possessed higher deposition efficiency than that of conventional powders. In addition, it was found that spraying parameters had strongly influence on microstructure and microhardness of zirconia coatings. Therefore, in order to obtain high quality zirconia coating, proper spraying parameters must be considered.
Comparison of In-Flight Particle Characteristics and Coating Properties While Spraying NiCrBSi Powder with Different Spraying Processes
Authors: Planche M.P. , Liao H. , Coddet C. 
Published: July 2022

Abstract
The aim of this study was to compare different processes for a spraying NiCrBSi powder in order to understand how the coating properties are influenced by the particle characteristics. For that, three processes were tested: atmospheric plasma, HVOF and flame spraying. The plasma torch was a classical F4 gun from Sulzer-Metco, the HVOF gun was the CDS system manufactured by Sulzer-Metco and the flame spray gun was a Castolyn 8000 system. For each spraying process, the particles were analyzed using the DPV 2000 (Technar Ltd) at the distance corresponding to the coating build up. Particles velocity and temperature data were then correlated to the coating quality. Results indicate that the choice of the spraying technique induces important modifications in the coating properties in terms of adherence, porosity level, hardness and Young modulus. Changes in particle velocity and temperature are the key parameters determining the coating properties.
Evaluation of the Fracture Strength of Thermal Sprayed Coatings with Cracks
Authors: Kaneko K. , Ohmori A. 
Published: July 2022

Abstract
Fracture strength of a WC-12Co thermal sprayed coating is investigated experimentally and analytically. In the experiments, a pair of coated butt cylindrical specimens is subjected to combined tension with torsion stresses. Stress distributions in the coating at critical loading conditions are analyzed by using FEM analysis and the fracture criterion of the coating is investigated. It is found that normal stress distributions are common to all cases of testing stress conditions and so fracture condition of the brittle coating is represented as K ≧ Kcr in the normal stress distribution even under mixed deformation mode I and III. By using the experimental method presented in this paper and the corresponding FEM analysis, an approximation for the critical bonding strength of a coating under shearing load can be estimated.
Study on the Behavior of Arc-Spraying Coatings with High-Temperature Erosion Resistance
Authors: Liu Wei , Zeng Ke-li , Song Xi-jian , Wu Chaojun 
Published: July 2022

Abstract
Two cored wires L1 and L2, have been developed to produce arc-spraying coatings for treating high temperature erosion wear of four tubes in the power station, grit erosion experiments under various conditions such as temperature, incident angle, grit weight and shocking velocity have been taken, results show that coating L1 prepared by the new cored wire is more erosion resistance than the comparative materials 20g steel, coating L2 has different behavior varies with the distinct state, from the basis of surface structure and erosion performance, it is also concluded that coating L1 and L2 show mainly plastic erosion wear behavior during the grit erosion process.
Microstructure and Properties of FeNb and FeSi Coatings Obtained by HVOF Thermal Spraying
Authors: Cherigui M. , Fenineche N.E. , Coddet C. , Craven J. 
Published: July 2022

Abstract
Iron-based alloys were sprayed on a copper substrate using high velocity oxy-fuel process to form amorphous coatings. Two modes of cooling were used, water and air, in order to increase the particles speed solidification. Structures and magnetic properties of FeNb and FeSi deposits have been characterized. X-ray diffraction patterns showed that FeNb coatings present a partially amorphous structure, however, in the case of FeSi alloys, their structure is completely crystalline. The use of the two modes of cooling has given almost the same results for the two types of powders. As a consequence, magnetic properties of this material could be improved by using a heat treatment.
Development of Ferrous Powder Thermal Spray Coatings on Cylnder Bore in Diesel Engine
Authors: Uozato S. , Nakata K. , Ushio M. 
Published: July 2022

Abstract
Aluminum alloy has been gradually utilized in cylinder block instead of ferrous casting material for weight reduction in automobile industry these days. In order to acquire more weight reduction, a new liner-less technology - without cast iron liner used - is putting into practice in the fields of aluminum cylinder block and the target is for diesel engine. However, diesel fuel's impurity "sulfur" element and corrosive attack risk, such as sulfuric acid generated to the surface of liner is higher than gasoline fuel. Because of such disadvantage, wear and corrosion resistances applied to the inner cylinder-bore are required in order to achieve this liner-less aluminum cylinder block. This research is intended to accomplish both wear and corrosion performances using plasma thermal spray technology and to verify the feasibility of application to actual engine bore. A newly-developed ferrous powder (Fe-C-Ni-Cr-Cu-V-B alloy) revealed extremely excellent corrosion and wear resistances, compared with currently used bulk casting materials such as Fe-C-Si-B alloy and Fe-C-Si-Mo-B alloy for cylinder liner. For the last time, the new ferrous alloy powder was applied to actual engine bore by using Rota-Plasma spray coating. The experimental results with engine bore presented potential equivalent to current engine bore.
High Performance Coatings Produced by Internal Plasma Spraying on Engine Blocks of New Generation
Authors: Barbezat G. 
Published: July 2022

Abstract
Since about the year 2000, cast aluminum automobile engine blocks have been coated in production lines using internal plasma spraying technology. Using this approach, the coefficient of friction between the cylinder wall and the piston assembly can be reduced to 30% and oil consumption is reduced of a factor two in comparison with cast iron. The extremely low wear rate of the friction elements increases engine life and reduces maintenance costs. The fuel consumption of the cars can be reduced from 2 to 4% in the case of gasoline and diesel engines. The coating costs are strongly dependent on production volume. For high volume production, the costs can be similar to those for cast iron liners. This paper reviews results from laboratory and field tests evaluating the performance and cost efficiency of plasma sprayed engine block liners.
Cast Iron Coatings Containing Graphite Structure by Atmospheric Plasma Spraying
Authors: Ozdemir I. , Ueno T. , Tsunekawa Y. , Okumiya M. 
Published: July 2022

Abstract
The excellent wear-resistant performance of cast iron coatings considerably depends on the formation of graphite structure with an inherent self-lubricating property. In the present study, two types of cast iron powders produced by gas- (GA) and water-atomization (WA) were deposited on an aluminium alloy substrate by atmospheric DC plasma spraying. WA powders are generally characterized by high oxygen content, irregular appearance and inexpensiveness compared with those of GA powders. Although alloying elements of silicon and aluminium work as a strong graphitizer and anti-oxidizer, graphite structures are not recognized in coatings sprayed with as-atomized high silicon and aluminium powders. Therefore, either pre-annealing of powders or post-annealing of coatings is required to achieve cast iron coatings containing graphite structure. A marked decrease in graphite occurs to the coatings with pre-annealed GA powder, since there exists precipitated graphite mainly on a GA powder surface. A short period of post-annealing is also valuable for graphitization. The weak oxide layers are observed in coating cross-sections with GA and WA powder, however, their oxidized levels are much lower than those with bearing steel powder containing low silicon and aluminium. Hence, graphitized cast iron coatings sprayed with inexpensive WA powder exhibit a splendid anti-wear performance.
Formation of TiO2 Photocatalyst Through Cold Spraying
Authors: Li Chang-Jiu , Yang Guan-Jun , Huang Xin-Chun , Li Wen-Ya , Ohmori Akira 
Published: July 2022

Abstract
TiO2 photocatalyst in the form of coatings are of many advantages over those in powder form in practical applications. Various processes have been used to form TiO2 coatings including sputtering, Sol-Gel, vapor deposition, thermal spraying, etc. In all those processes, the coatings are deposited under temperatures from 300 to more than 2000 °C. High temperature during those processing may change the microstructure of the as-received TiO2 to a less effective one for photocataltyic performance. In the present study, TiO2 coating was deposited through cold spraying process using two types of powders, which were agglomerated with anatase ultra-fine particles in micro-size and nano-size. Microstructures of both powders and deposited coatings were characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. The results showed that the nanostructured TiO2 coatings were evenly deposited on stainless steel substrate through cold spraying. The thickness of the deposits reached up to 15 µm. The coating presented a rough surface and porous structure. Owing to the low temperature of spray powders, no change occurred to the phase and grain size of TiO2 during deposition process. It was also found that the cold sprayed TiO2 deposits were photocatalytically active for photodegradation of acetaldehyde.
Study of Aluminum Bronze Coating By Cold Spray Process
Authors: Xiong Tianying , Gu Chunlei , Zhang Weiqiang , Wu MinJie , Wu Jie , Jin Huazi , Li Tiefan 
Published: July 2022

Abstract
Cold spray is a promising potential material deposition process of which the main advantage is that the material to be sprayed is not heated to high temperatures. But one problem encountered is that the coatings for some powders are not well bonded to the substrate. The mechanisms of bonding of cold-sprayed coating to substrates are not at present clearly understood. This work considers the deposition of aluminum bronze by cold spray process onto stainless steel. The micro diffusion along the interface between the substrate and coating as well as the beta-phase depletion of the cold-sprayed coating is observed. Results obtained are important not only for understanding the interaction of the particles with the substrate but also for optimizing the spray parameters for the cold spray process.
Deposition of Copper by Cold Gas Dynamic Spraying: an Investigation of Dependence of Microstructure and Properties of the Deposits on the Spraying Conditions
Authors: Calla E. , McCartney D.G. , Shipway P.H. 
Published: July 2022

Abstract
In the Cold Gas Dynamic Spray (CGDS) process, coatings are deposited by the virtue of the high particle velocity achieved by the use of converging-diverging (de Laval) nozzle along with suitable particle characteristics and process parameters. In this study copper coatings were deposited on aluminium substrates using helium as the accelerating gas. The influence of the CGDS conditions, primarily driving gas temperature and pressure, on the nature of the deposited coatings and the deposition efficiency of the process were investigated. The results indicate that it is possible to deposit copper coatings at a wide range of process conditions, with successful deposition being observed with the driving gas at room temperature and 11 bar pressure (a condition where the nozzle is still choked). However, the nature of the coatings is strongly dependent upon the processing conditions. With room temperature driving gas, an increase in pressure lead to an increase in deposition efficiency, and increase in substrate deformation and an increase in microhardness in the deposit due to higher levels of work hardening. The use of driving gas at temperatures as low as 473 K resulted in recrystallisation in the deposit and a decrease in tendency to debond due to stress relief during recrystallisation. Recrystallisation also manifested itself in reduced hardness. The sensitivity of the recrystallisation conditions to the traverse speed of the jet over the substrate indicated that these processes are initiated by the impingement of the hot gas jet onto the deposit following deposition and not by changes in velocity or temperature of the particles upon impact.
Characterization of Microstructure of Nanostructured Fe-Si Coating Deposited by Cold Spraying
Authors: Li Chang-Jiu , Li Wen-Ya , Ma Wen-Hua , Fukanuma H. 
Published: July 2022

Abstract
The low temperature characteristic of cold spraying makes it possible to deposit the coating of temperature sensitive materials, such as nanostructured material, without any significant change in the microstructure of feedstock. In the present study, the Fe and Si powders of particle size less than 75 µm were mixed at a composition of 10wt%Si and ball-milled to produce the nanostructured feedstock. Cold spraying process was used to deposit coating with nitrogen as a driving gas at different temperatures. The microstructure of the as-sprayed nanostructured Fe-Si coating was characterized using optical microscopy, scanning electron microscopy and transmission electron microscopy (TEM). The grain sizes of the feedstock and as-sprayed coating were estimated based on X-ray diffraction analysis. The results showed that the nanostructured Fe-Si coating can be deposited by cold spraying using the ball-milled powders as feedstock. The as-sprayed coating presented a dense microstructure. The average grain size of the as-sprayed coating was comparable to that of the corresponding milled feedstock. No significant effect of the temperature of driving gas on the microstructure of cold-sprayed nanostructured Fe-Si coating was recognized. Moreover, TEM analysis showed that the amorphous phase was present in the as-milled powders and the as-sprayed coating along with the nanocrystalline.
Deposition of Amorphous Metallic Coatings by Thermal Spraying
Authors: Rohan P. , Bouaricha S. , Legoux J.-G. , Moreau C. , Ctibor P. , Nourouzi S. , Vardelle A. 
Published: July 2022

Abstract
Amorphous metallic coatings are of high interest because of their good wear and corrosion resistance as well as their high hardness and toughness relative to the crystalline alloys with the same composition. Thermal spray that makes it possible to reach quenching rates in the order of 106-107 K/s, has the ability to deposit coatings with a high content of amorphous phase. However, very few studies dealt with the understanding of the spraying factors that affect the formation of the amorphous phase under thermal spray conditions. In this work, the relationship between temperature and velocity of the spray particles and coating characteristics is investigated. Special attention is given to the degree of amorphisation of the as-sprayed coatings. The latter were produced both by plasma and wire-arc spraying in order to get a larger range of particle parameters at impact and different particle heating history in the gas flow before impingement onto the substrate. A commercial iron-based alloy available both in powder and wire forms was used. Microstructural analyses show that the as-sprayed coatings are partially amorphous and that the proportion of the amorphous phases depends on the sizes of the sprayed particles as they control the heating and acceleration of particles in the gas flow and their cooling rate on the substrate.