bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Rare Earth Elements on the Corrosion Resistance of Fe-Cr-Ni Thermal Sprayed Coatings
Authors: He D.Y. , Jiang J.M. , Yan Y.Q. , Xiong D.J. 
Published: September 2022

Abstract
The advantage of cored wires, a new type of material in thermal spraying, is that it is easy to control their composition and convenient to develop new materials. This research is aimed at developing the Fe-Cr-Ni austenitic stainless steel corrosion-resistance thermal-sprayed cored wires with rare earth elements added. The experiments are conducted with arc spraying. The anodic polarization curves of the sprayed coatings of the developed wires and of the 1Cr18Ni9 solid wire are drawn by using MODEL 351 corrosion measuring system in the 0.5mol/L sulfuric and 3.5wt.% sodium chloride solution at a temperature of 20° C . For the sake of comparison, the substrate and the 18-8 wrought stainless steel are also measured. Results to date indicate good usability of thermal sprayed coatings in all the developed wires. Owing to added rare earth elements, the corrosion-resistance of coatings increases in the 0.5mol/L sulfuric solution. The wires with RE-3 added have exhibited good corrosion-resistance. Deterioration of the corrosion-resistance in the 3.5wt.% sodium chloride solution is caused by generation of crevices and inclusions between the deposited particles.
Influence of Thermal Spray Process on the Corrosion Behavior of High-Density 316 Stainless Steel Coatings in Simulated Marine Environment
Authors: Simard S. , Arsenault B. 
Published: September 2022

Abstract
Under marine and coastal conditions, the degradation by corrosion of low-alloyed steels is generally observed. In order to overcome such important corrosion problems, the use of thermal spray coatings made of noble materials may be an attractive solution. 316 stainless steel thermal spray coating, an iron alloy coating, is often considered for corrosion protection because of its low material cost. Also, the high velocity oxy-fuel (HVOF) is often the selected coating process because it is known to provide coatings with a very low porosity level preventing the corrosive media to reach the substrate. The present paper compares the corrosion behavior of wrought 316 stainless steel with sprayed coatings made of the same alloy on 1020 mild steel. The corrosion behavior of materials is studied under salt fog conditions and with electrochemical techniques in brine simulating the marine environment. The coatings have been sprayed by HVOF under usual conditions. The results of this study demonstrate that the material behavior with regard to corrosion is process dependent . The HVOF sprayed stainless steel coating is much more sensitive to corrosion than wrought stainless steel. Corrosion product appearing on the samples is not only linked to the corrosion of the substrate by diffusion of the corrosive solution through pores but is also generated by intrinsic corrosion of coating itself. An enhanced sensitivity of the coating with regard to corrosion is attributed to the surface of particles or droplets, which are most likely degraded during the spraying process. However, thermal spray coatings having performances as good as wrought stainless steel can be obtained. In the present work, it is demonstrated that coatings obtained using vacuum plasma spray (VPS) have similar corrosion properties than wrought stainless steel in simulated marine environment. The industries considering corrosion protection of their components in marine environments by the use of stainless steel coatings must be aware of the reliability of their coatings. During the usual HVOF spray process, particles or droplets of stainless steel 316 are subject to important modification leading to a loss of performance against corrosion. Oxidation of alloying elements necessary to obtain a good stainless steel most likely occurs. However, the use of vacuum sprayed stainless steel coatings results to efficient protection against corrosion in marine environment.
Development of Dense Corrosion Resistant Coatings By an Improved HVOF Spraying Process
Authors: Kawakita J. , Kuroda S. , Fukushima T. , Kodama T. 
Published: September 2022

Abstract
For 6 years, we have developed corrosion resistant coatings for the marine structural steels by using a thermal spray technique. Such a coating requires primarily impermeability and secondarily cleanliness. In order to make denser and highly corrosion resistant coatings, we selected spray materials and improved fabrication processes. In addition, some new methods were designed to evaluate the sprayed particle’s state and coating properties with high accuracy and sensitivity. An inert gas shroud system was attached with the commercial HVOF apparatus and this attachment enabled inflight spray particles to be accelerated over 750 m·s-1 and simultaneously to avoid to be oxidized. The coating of HastelloyC nickel base alloy by this process had zero through porosity and 0.2 mass% of oxygen content, leading to be comparable to the bulk material of HastelloyC in terms of corrosion resistance. This coating, formed on steel, demonstrated an excellent protective performance over 10 months in the marine exposure test.
Studies of Cavitation Resistant Thermally Sprayed and Welded Coatings
Authors: Marques P.V. , Lima C.R.C. 
Published: September 2022

Abstract
Cavitation is one of the most serious problems that affect hydraulic systems and components, mainly power turbines. Welding deposits have been traditionally used to protect components from cavitation damage. Since the protection process is normally associated to maintenance repairs (welding overlay), there are some difficulties related to weld distortion and residual stresses as well as some economic problems regarding to process efficiency and time. Thermal spraying has been recently tested as an alternative to welding in such applications. Some of the materials tested have been proved to be ineffective or inappropriate due to several causes like poor adhesion or mechanical damage. This work refers to a study of wear resistant coatings applied by thermal spraying and welding for cavitation resistance applications. The coatings were applied by High Velocity Oxygen Fuel (HVOF) and Flame Spraying and by Shielded Metal Arc Welding (SMAW). Hardness, roughness as well as cavitation resistance characteristics of the coatings were evaluated. The results show that the obtained coatings are promising for protection in cavitation resistance applications.
Erosion Behavior of WC-10Co-4Cr HVOF Coatings
Authors: Legoux J-G , Arsenault B. , Hawthorne H. , Immarigeon J-P 
Published: September 2022

Abstract
Among the WC based cermets coating materials, those using the 10%Co-4%Cr matrix demonstrate excellent wear and corrosion properties. In this paper the erosion behaviors of WC-10%Co-4%Cr HVOF coatings was evaluated under different erosion conditions. The coatings were obtained from the JP-5000 gun using kerosene as fuel and the Diamond Jet gun using propylene and hydrogen. Two types of powder morphology were used: the first type was coarse and angular while the second was smaller, porous and spherical. The coatings were submitted to dry and slurry erosion. Erosion tests were performed at room temperature for both dry and slurry erosion. Dry erosion was evaluated by jet erosion while for slurry erosion, two different tests were performed: Coriolis and jet impingement erosion. Experimental results show that for the same powder, the erosion resistance measured by the Coriolis test exhibits 100% variation while for jet impingement it varies only by 20% depending on gun and spray conditions. The results also show that the powder selection is one of the key factors controlling the coating performance. The selection of powder can affect the Coriolis erosion resistance by more than 300% and the dry and slurry erosion resistance by 75%. The results are analyzed as a function of the processing and coating microstructure.
Erosion and Abrasion Resistance of Boride and Carbide-Based Weld Overlays
Authors: Lapointe F. , Dallaire S. 
Published: September 2022

Abstract
WELD OVERLAYS, more specifically chromium carbide weld overlays, have been widely used as thick coatings to protect critical plant components from abrasion wear. These thick coatings have been also considered in applications involving severe erosion, their thickness being synonymous with long life protection. Recently, boride-based arc-sprayed coatings have been developed especially for erosion control. They have demonstrated their superiority in erosion resistance over various coatings including chromium carbide submerged arc overlays. This work was undertaken to produce dense boride-based coatings comparable in thickness with carbide-based overlays. A GMAW (Gas Metal Arc Welding) welding procedure was developed for depositing boride-based overlays from cored wires. A comparative evaluation of the hardness, erosive and abrasive wear resistance of these boride-based overlays with regards to chromium and tungsten carbide overlays was carried out. Abrasion and erosion wear testing demonstrated that boride-based overlays showed higher abrasion and erosion resistance than chromium and tungsten carbide-based overlays. Overlays with higher wear resistance can be obtained if appropriate welding procedure is used to decrease weld bead dilution and therefore increase coating hardness. Results also showed that boride-based coatings deposited by arc spraying posses higher erosion resistance than those produced by the welding process.
Plasma Sprayed Nanostructured Zirconia Coatings for Wear Resistance
Authors: Ding Chuanxian , Chen Huang , Liu Xuanyong , Zeng Yi 
Published: September 2022

Abstract
Nanostructured and conventional ZrO2 coatings were deposited by plasma spraying. The wear and friction properties of these coatings against stainless steel under dry and water lubricated conditions were comparatively studied respectively. The results obtained showed that the wear resistance of the coating produced using the nanostructured zirconia powder is greatly improved compared with the coating produced using the conventional powder. The wear rates of the nanostructured zirconia coatings are two-fifths and half of those of conventional zirconia coating under dry and water lubricated conditions. It is explained in terms of the optimization of microstructure and higher microhardness of the nanostructured coating. In comparison with the dry condition, the water lubrication improved the tribological properties of both nanostructured and conventional zirconia coatings, which could be attributed to the formation of a smooth surface mainly consisting of zirconia and Fe3O4.
Sliding Wear Evaluation of Hot Isostatically Pressed (HIPed) Thermal Spray Cermet Coatings
Authors: Stoica V. , Ahmed R. , Itsukaichi T. , Tobe S. , Escribano M. 
Published: September 2022

Abstract
The aim of this preliminary investigation was to ascertain the synergetic potential of two process technologies of thermally spraying and HIPing (Hot Isostatic Pressing) for tribological applications and address the key design factors, which need to be considered for successful applications of HIPed thermal spray WC-NiCrBSi coatings. The relative performance of the as-sprayed and hot isostatically pressed WC-NiCrBSi functionally graded coatings was investigated in sliding wear conditions. Results indicate that HIPing post-treatment can improve the sliding wear resistance of WC-NiCrBSi coatings. These coatings were deposited by a High Velocity Oxy-Fuel - JP5000 system and HIPing process was carried out at two different temperatures of 850°C and 1200°C. This study shows that un-capsulated HIPing can be successfully applied to functionally graded WC-NiCrBSi coatings, which has economical as well as technical incentives for industrial applications. Sliding wear tests were carried out using a high frequency reciprocating ball on plate rig using steel and ceramic balls. Results are discussed in terms of powder manufacture method, microstructural investigations, phase transformation, mechanical properties and residual stress investigations. Phase analysis by X-ray diffraction revealed transformations, which altered the phase composition such as the elimination of secondary phase W2C and metallic W and the formation of new phases containing Ni, Si and B after the post-treatment. The measurements of hardness, Young’s modulus and residual stress indicate that substantial improvements can be achieved due to simultaneous application of temperature and pressure during the HIPing post-treatment. Hardness and Young’s modulus measured by indentation method, increased after the HIPing process due to the transformations in the morphology and phase composition of the coatings. The residual stress evaluations by sin2Ψ technique using synchrotron x-ray diffraction showed a relaxation of residual stress fields in the coating with increasing temperature of the HIPing process.
Formation of Intermetallic Phases by Laser Alloying of Thermally Sprayed Ti and Al Coatings for Enhanced Wear Resistance of Lightweight Materials
Authors: Wilden J. , Frank H. 
Published: September 2022

Abstract
Lightweight materials such as Al and Ti alloys tend to show poor wear resistance. However, laser alloying of thermally sprayed coatings can be used to form intermetallic phases within the surface area to overcome this disadvantage and to build a metallurgical bond between substrate and coating. Such phases formed in an exothermic reaction may show excellent corrosion behaviour and wear resistance. These reactions can be used to influence the surface properties by remelting metallic coatings on Al or Ti substrates. With respect to the wear behaviour, Ti and Al intermetallics are of great interest. Ti and Al alloys were coated by Al, Ti, and Ni respectively. The different structures on the surface of the alloys depend first on the laser processing parameters resulting in the overheated melt and as well as the latent heat of the formed intermetallic phases. The experimental results clearly show that for short dwell times the latent heat dominates the solidification process and that at high solidification rates the microstructure formation becomes nearly independent from the process parameters. This effect is of special interest for industrial applications as quality requirements ask for robust processes. The paper discusses the metallurgical fundamentals of intermetallic phases and the energy balance of the solidification while giving a deep insight into the influence of different process parameters. Lastly, the properties of alloyed surfaces are discussed.
The Effect of Chlorine on Degradation Mechanisms of Thermal Sprayed Coatings at Elevated Temperatures
Authors: Uusitalo M. , Vuoristo P. , Mäntylä T. , Berger L-M , Backman R. 
Published: September 2022

Abstract
The significance of biofuels and the other chlorine-containing fuels in energy production is in strong increase. Serious erosion-corrosion problems in boilers combusting fuels with high chlorine-content have been detected frequently. A series of erosion-corrosion and corrosion tests were performed on thermal sprayed coatings and coating precursors in chlorine-containing environments in order to evaluate possibilities to utilize thermal sprayed coatings for erosion-corrosion protection in boilers combusting chlorine-containing fuels. A series of hot erosion and erosion-corrosion tests were performed on thermal sprayed coatings at elevated temperatures with and without chlorine. Carbide-containing HVOF coatings performed well in hot erosion tests, but they were completely destroyed in the presence of chlorine due to rapid oxidation of carbides. Metallic HVOF coatings with high chromium content performed well in both conditions. Iron-based arc-sprayed coatings with unhomogeneous microstructure suffered more hot erosion and erosion-corrosion damages than metallic HVOF coatings. The E-C (erosion-corrosion) resistance of carbide-containing coatings in the presence of chlorides was worse than expected. A series of oxidation tests were performed on various carbides in order to elucidate the effect of chlorine on high temperature oxidation behavior of carbides. TGA and isothermal oxidation tests proved that gaseous chlorine-containing species and also solid chlorides have a detrimental effect on oxidation resistance of tested carbides.
Effect of Thermal Sprayed Al on the Steam Oxidation Resistance of 9Cr-1Mo Steel
Authors: Sundararajan T. , Kuroda S. , Itagaki T. , Abe F. 
Published: September 2022

Abstract
Thermal spray of Al was carried out on the modified 9Cr-1Mo steel to evaluate the steam oxidation resistance of the sprayed Al coating. Atmospheric plasma spray process (APS) was used to coat aluminum on sandblasted 9Cr-1Mo steel substrate. The coating thickness was around 40 µm. The coated specimens were steam oxidized in four different temperatures, ranging from 600 to 750°C. The results show that the scale growth occurred in the interface between coating and substrate subsequently it penetrated into the coating structure. Al diffused into the alloy substrate with high solubility. The diffusion increased with increase in the steam temperature and test duration. Diffused aluminum formed the high hardness intermetallic compound in the substrate near the coating/substrate interface. With increase in the test duration, the intermetallic compound moved towards the bulk and at prolonged aging, it became dissolved. This was identified from the decrease in the micro hardness values at coating/substrate interface at prolonged duration. The scale growth at the substrate surface of Al sprayed steel was much controlled compared to the uncoated specimens.
Activated Combustion HVAF Coatings for Protection against Wear and High Temperature Corrosion
Authors: Verstak A. , Baranovski V. 
Published: September 2022

Abstract
Activated Combustion HVAF Spraying (AC-HVAF) involves a jet of air-fuel combustion products to deposit coatings of metallic and carbide powders. In the process, spray particles are heated below their melting temperature while accelerated to velocity typically 700-850 m/s, forming a coating upon impact with a substrate. Extremely low oxygen content and high density are distinguished features of the AC-HVAF coatings, resulting in their excellent performance under conditions of severe wear and corrosion. Besides new level of coating quality, the AC-HVAF process demonstrates outstanding technological efficiency and spray rates 5-10 times exceeding those of the HVOF counterparts. The paper presents results on characterization of selected metallic and carbide coatings and describes their applications.
Microstructure and Wear Performance of Spray & Fused NiCrBSiC/WC Composite Coatings
Authors: Kim H.J. , Hwang S.Y. , Lee C.H. 
Published: September 2022

Abstract
Characterization of flame sprayed and furnace fused NiCrBSiC alloy coatings with two different carbon contents and 15~45 wt.% WC-Co addition is described in terms of microstructure, microhardness, and differential thermal analysis. Microstructural development of these coatings before and after fusing treatment is discussed to identify the precipitates in the coatings. Optimum fusing conditions (time and temperature) for wear testing sample are investigated in terms of microhardness and porosity of the coatings. Wear performance of these coatings is also investigated by two-body and three-body abrasive and dry sliding wear experiments. Optimum tungsten carbide content of the coatings is also selected to improve wear performance and thus enhance the service life of the process roll for cold rolling steel plant. Finally, microstructure and microhardness of the furnace and induction fused coatings are compared with emphasis on the interface between the coating and the steel substrate.
Improved Heat Transfer by RF Plasma Produced Structured Surfaces
Authors: Bouyer E. , Henne R. , Müller-Steinhagen H. , Schäfer D. , Asano H. 
Published: September 2022

Abstract
Structured surfaces are needed for improving the heat transfer in a lot of industrial processes. The paper deals with the production and the characterization of coatings with rough and porous surface. Structured coatings of inconel or copper are deposited on copper tubes by means of radio-frequency vacuum plasma spraying. The microstructure as well as the surface roughness of the coatings are investigated. Boiling experiments are carried out on the coated tubes to measure their heat transfer coefficient. The results show that the coated tubes exhibit improved heat transfer values in comparison to smooth tubes. The enhancement ratio can reach more than 20 for inconel coatings.
Modified Nozzle for the Atmospheric Plasma Spraying
Authors: Schwenk A. , Nutsch G. , Gruner H. 
Published: September 2022

Abstract
A modified Laval-like-contour for a convergent-divergent nozzle is presented for the Atmospheric Plasma Spraying (APS). The influence of the nozzle design on the thermal and deposition efficiency as well as on the arc voltage fluctuations and the sound level of the plasma torch are investigated and compared with former investigations. The improvements of the quality of DC-Plasma sprayed Al2O3 coatings by the nozzle design is shown by the coating porosity, adhesive and breakdown strength. A 2D-model presents the gas dynamics inside the nozzle. The intention of this study is to promote the industrial application of convergent-divergent nozzles for the APS in conjunction with the optimisation of the plasma gas dynamics.
Characterization of LPPS Processes Under Various Spray Conditions for Potential Applications
Authors: Refke A. , Barbezat G. , Dorier J.L. , Gindrat M. , Hollenstein Ch. 
Published: September 2022

Abstract
Low Pressure Plasma Spraying (LPPS) is nowadays a well-established thermal spray process with a broad variety of important applications for functional surface coatings. The operating pressure for LPPS processes can vary in a wide range from typically 200 mbar down to only a few mbar. This leads to unconventional properties of the plasma jet, in terms of supersonic flow with strong shock structure at moderate pressure, towards rarefaction and frozen flow at very low pressure. In order to optimize and control the spray processes for specific applications, it is necessary to understand the underlying physical mechanisms. However, so far only limited knowledge has been established on the plasma jet properties and its interaction with the spray particles in LPPS conditions. We present several experimental investigations to characterize plasma spray processes under various pressure conditions. Measured plasma jet properties using a dedicated enthalpy probe system and imaging are combined with IR-pyrometry and velocimetry on the particles (DPV2000) to further improve the understanding of the plasma particle interactions. These results, along with spray deposit characterization, can be used to optimize the coating properties and explore further potential applications.
Effect of Chamber Pressure and Spray Distance on the Plasma Sprayed Alumina Deposition
Authors: Sodeoka S. , Suzuki M. , Inoue T. 
Published: September 2022

Abstract
The effect of the chamber pressure and the spray distance on the splat formation of the plasma sprayed spherical alumina powder was investigated. The velocity and the surface temperature of the sprayed particles were measured by DPV2000. The particle temperature was changed in wide range by the chamber pressure; a solid core remained in the sprayed particle at 30 kPa and the surface temperature reached to the boiling point of alumina over 90 kPa. At the higher temperature, the splashing behavior was explained by the model of liquid film stability. However, in the cooling stage after coming out from the plasma flame, the inhomogeneous temperature in the sprayed alumina particle led to the complex splashing. The temperature distribution in the molten particle is very important to consider the splat formation.