bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Model of Controlled Cooling of Steel Hot Rolled Bars
Authors: Smoljan Božo , Iljkić Dario , Senčić Bojan , Vertnik Robert 
Published: March 2024

Abstract
Numerical model of controlled cooling in production of steel hot rolled bars was developed. By numerical model of controlled cooling is possible to predict a transient temperature field, microstructure evolution and hardness of rectangular steel bars during their cooling in cooling beds. The numerical model of transient temperature field is based on control volume method. The algorithm for prediction of hardness and microstructure distribution in steel bars is based on continues cooling transformation, (CCT) diagrams and real chemical composition. The numerical model and algorithm is completed to solve problems in controlled cooling of hot rolled bars in cooling beds. The controlled cooling are performed by special placement of hot rolled bars on cooling beds. Numerical model and computer program was experimentally verified by simulation of real industrial production of low alloyed steel bars. The verification of developed numerical model was performed by comparison of simulated hardness with experimentally evaluated results.
Evaluation and Control Technique of Cooling Unevenness by Quenching Oil
Authors: Homma Rikki , Ichitani Katsumi , Matsumoto Mika , Steiger Greg 
Published: March 2024

Abstract
In the heat treating process, it is important for parts to be cooled uniformly in order to reduce distortion while obtaining target hardness. However, it is difficult to cool the parts uniformly due to the presence of the vapor blanket stage in oil quenching. In this study, we investigated the influences of cooling unevenness in various heat treatment conditions, such as the types of oils having different vapor stage lengths, and using varying agitation and oscillation rates with these oils. We found that cooling unevenness was decreased by using the quenching oil with a shorter vapor blanket stage length. Additionally, the cooling unevenness was decreased by agitation and oscillation compared to quenching without agitation. In conclusion, we found selecting a quenching oil with the shortest vapor blanket stage length and combining agitation and oscillation was the most effective method in reducing the distortion of parts after oil quenching.
Thermal Fatigue in Hot Work Tool Steels - A Review
Authors: Ribeiro da Silva Junior Ruy , Totten George E. , Carmo Vendramim João , Franceschini Canale Lauralice de Campos 
Published: March 2024

Abstract
Thermal fatigue is a dominant mechanism that causes premature failure in components exposed to high temperature. In order to extend the useful life of tools for hot work, studies have been conducted trying to understand the mechanisms involving thermal fatigue. Thus, different types of materials combined with different parameters of thermal and surface treatments have been investigated using thermal fatigue tests. This review addresses the main aspects of thermal fatigue as well as the main alternatives used to increase the resistance of the material to this type of failure.
Simulation of Temperature Profile in Longitudinal Welded Tubes During High-Frequency Induction Welding
Authors: Das Prerana , Inge Asperheim John , Grande Bjørnar , Petzold Thomas , Hömberg Dietmar 
Published: March 2024

Abstract
The temperature profile in the Heat Affected Zone (HAZ) during induction welding is one of the most important factors determining the weld quality of High-Frequency Induction (HFI) welded steel tubes. In this work, numerical computation of the 3D temperature profile in the steel tube has been done by coupling the electromagnetic model with the thermal model. The high-frequency current and the magnetic fields in the tube, coil and impeder have been evaluated. The resulting power from the induced current is used to evaluate the temperature in the joining edges of the tube. The continuous tube movement has been implemented by considering an additional transport term in the heat equation. The simulations consider non-linear electromagnetic and thermal properties of the steel when it undergoes temperature rise to the welding temperature. The temperature profile from the resulting simulation gives information to control the subsequent process of joining the edges of the steel tube.
True Single-Piece Flow Case Hardening for In-Line Manufacturing
Authors: Hart Tom , Korecki Maciej 
Published: March 2024

Abstract
Case hardening by carburizing is the most common heat treatment in mass production, which relies on atmosphere, or vacuum carburizing followed by oil or gas quenching and finally by tempering. Parts being heat-treated undergo the process in a configuration of a batch consists of hundreds or even thousands pieces. Under these circumstances, individual parts can’t help but be exposed to different process parameters in terms of temperature, atmosphere and quenching depends on their position within the batch. Parts near the outer portion of the load see a more rapid rise in temperature, are first exposed to the carburizing atmosphere and are more effectively quenched than parts located in the center of the batch. This can lead to significant variation from part to part and load to load; the resultant effective case depth deviation can be as high as 50%. Similarly, during quenching from hardening temperature distortion becomes highly unpredictable and unrepeatable. Modern industry demands greater precision and repeatability of results beyond those achievable by so-called traditional batch or continuous technologies and their associated equipment. Elimination of batches and focus on individual parts is the only true way to advance the industry. The article will introduce the first operational system for truly single-piece flow method for case hardening by low-pressure carburizing and hardening by high-pressure gas quench. The system treats each part individually and as such provides virtually identical process parameters, which results in extremely accurate and repeatable results. Quenching one part at a time in a specially design chamber, achieves more precise control and significantly reduces distortion so as to all make it possible to avoid post heat treatment hard machining operations. This single-piece flow heat treatment method is easily adapted into manufacturing and can be directly integrated into in-line manufacturing operations, working directly with machining centers. Materials handling and logistical issues are eliminated thus saving time and reducing unit cost. The results achieved on series of automotive gears will be reported and demonstrate incredible accuracy and repeatability, while significantly reducing distortion. Productivity and process costs prove the system to be highly competitive with other technologies. These proven advantages and savings.
Vacuum Carburizing Steel Alloys Containing Strong Carbide Formers
Authors: Ferguson B. Lynn , Li Zhichao , Sims Justin , Yu Tianyu 
Published: March 2024

Abstract
Carburizing grades of high strength steels, such as Ferrium C- 64 alloy, contain strong carbide forming elements such as chromium and molybdenum. Alloys with high amounts of strong carbide formers can form stable carbides during carburization that effectively block carbon diffusion and retard the carburization process. This is especially true for low pressure carburization. To achieve the desired case depth, the low pressure carburization process consists of a series of rapid boost and longer time diffusion cycles. One problem is how to determine an acceptable carburization schedule. This paper will discuss a methodology used to develop the data for Ferrium C-64 so that a proper low pressure carburizing schedule could be determined. Integral parts of this methodology are experiments to determine carbon diffusion rates, carbide formation kinetics, and carbide dissolution kinetics, and use of these data in computer software to simulate the process and to determine the proper schedule.
Copper Evaporation During Low Pressure Carburizing
Authors: Jones Trevor , Osterman Virginia , Jordan Donald 
Published: March 2024

Abstract
Low pressure carburizing (LPC) in a vacuum furnace is increasingly the preferred method of case hardening for aerospace gears, and acetylene is often one of the gases used in the process. Selective case hardening is common with gears, where certain sections of a part are “stopped off” or “masked” to prevent carburization at those locations. For aerospace parts, the masking used is typically copper electroplating. The low pressures and high temperatures used in LPC lead to copper evaporation, which contaminates the vacuum furnace hot zone and components. In a worst-case scenario, deposited copper can lead to short-circuiting of power feedthroughs. This study looks at the effect of vacuum and partial pressure gases on copper evaporation and its application in production processes.
Friction and Wear Properties of (Ti,Mo)(C,N) Hardmetal Coatings Prepared by Gas and Liquid Fuel HVOF Processes
Authors: Berger L.-M. , Kitamura J. , Kasahara F. , Yamada J. , Sato K. , Vuoristo P. , Milanti A. , Niemi K. , Houdková Š. , Savková J. 
Published: March 2024

Abstract
This paper presents the results of a study on the tribological properties of TiC-based coatings deposited by HVOF spraying. Four powder feedstocks consisting of (Ti,Mo)(C,N) hardmetal with Ni and Co binders were prepared by agglomeration and sintering. The feedstocks differ in composition and particle size distribution, the latter being optimized for fuel type and equipment requirements. Coating specimens are evaluated based on microstructure, hardness, bonding strength, and friction and wear behavior. The results are presented and correlated with spray parameters, equipment differences, and feedstock characteristics.
Macroporous Titanium Coatings by Thermal Plasma Spray
Authors: Robotti P. , Sabbioni A. , Glass L. , George B. 
Published: March 2024

Abstract
This paper presents a summary of some of the research conducted on sponge-like titanium coatings developed for orthopedic use. It assesses the pore structure, adhesion properties, and in-vitro and in-vivo biological characteristics of porous titanium coatings deposited by vacuum plasma spraying on metals, PEEK polymer, and two bioceramics, Mg-toughened ZrO2 and ZrO2-toughened Al2O3. The plasma sprayed coatings show good flexibility in terms of pore size (100-800 µm), overall porosity (40-70%), and coating thickness (600-1500 µm).
Study on the Restoration of Aluminum Aerospace IVD Coatings Using Cold Gas Dynamic Spray
Authors: MacDonald D. , Jodoin B. , Gaydos S. , Pollack M. , Falkowski J. 
Published: March 2024

Abstract
Ion vapor deposition is a physical vapor deposition process often used to apply pure aluminum coatings to aerospace parts for corrosion protection. These coatings, however, are vulnerable to damage during manufacturing and use, leaving the underlying material susceptible to corrosion. The aim of this study is to develop an economical and practical technique for the repair and restoration of damaged aluminum IVD coatings using available cold gas dynamic spraying equipment. Based on the porosity, surface finish, adhesion strength, and corrosion performance of the repair coatings, cold gas spraying is shown to be a strong candidate for restoring damaged aluminum coatings on aerospace parts.
Strength and Wear Properties of Stainless Steel Coatings Produced by Cold Spray with Various Powder Sizes
Authors: Vo P. , Irissou E. , Kudapa S. , Nestler M. 
Published: March 2024

Abstract
Cold spray processing of stainless steel coatings, which represent a cost-effective method for wear and corrosion resistance, has been demonstrated as technically feasible. However, these coatings have very low tensile strength in the as-sprayed condition and may also exhibit a marginally higher wear rate. In this study, the cold spraying of 316L stainless steel coatings was investigated to assess the effect of powder size distribution and post-spray heat treatment on strength and wear properties. Coatings on aluminum and steel substrates were produced with a feedstock powder obtained in three particle size distributions. All coatings were deposited under the same conditions using nitrogen as the propellant gas, and then annealed at the optimum temperature. The microstructure and mechanical properties of both as-sprayed and heat-treated coatings were evaluated and the results are presented in the paper.
Multi-Response Optimization of Process Parameters for Low-Pressure Cold Spray Coating Process Using Taguchi and Utility Concept
Authors: Goyal Tarun , Sidhu T.S. , Walia R.S. 
Published: March 2024

Abstract
This paper presents the decision-making process used to simultaneously optimize the thickness and density of copper coatings produced by low-pressure cold spraying. Utility values based on both process parameters are analyzed for optimization using a Taguchi approach. The selected input parameters of powder feeding arrangement, substrate material, air stagnation pressure, air stagnation temperature, and standoff distance are shown to significantly improve the utility function of interest. The percentage contributions of the input parameters to optimize coating density and thickness are substrate material (50.03%), standoff distance (28.87%), air stagnation pressure (6.41%), powder feeding arrangement (4.68%), and air stagnation temperature (2.64%).
Velocity Measurement of Sprayed Particles and Coatings Fabrication of Titanium Alloys by High-Pressure Warm Spray
Authors: Kuroda S. , Molak R.M. , Watanabe M. , Araki H. , Katanoda H. , Sun B. , Ohno N. , Fukanuma H. 
Published: March 2024

Abstract
This study investigates particle velocities achieved by high-pressure warm spraying. Commercially pure titanium (CP-Ti) and Ti-6Al-4V powders were deposited on different substrates while varying spray parameters to determine their effect on particle velocity and coating quality. Particle image velocimetry was used to measure particle velocity, which peaked at 1,000 m/s. Coatings obtained under optimized conditions were characterized based on porosity, oxygen content, and hardness. The results show that the increased velocity of high-pressure warm spraying has significant beneficial effects in terms of improving density and controlling porosity and oxygen content.
Effect of Liquid Feedstock on Downstream Cold Spray Nozzle
Authors: Farvardin E. , Karimi M. , Villafuerte J. , Dolatabadi A. 
Published: March 2024

Abstract
In this study, a downstream injection cold spray nozzle is modeled numerically under various loadings. Instead of micron-sized particles, liquid feedstock as a carrier of nanoparticle suspension is fed into the nozzle through a port located 6 mm downstream of the nozzle throat at the diverging section. Water is used as the liquid carrier with a droplet size distribution of 5-100 µm and liquid-to-gas ratio ranging from 5 to 15%. The radial injection of droplets is simulated by Lagrangian particle tracking which includes the effects of heating and evaporation. The effect of the feedstock on downstream flow is analyzed and the optimum solid-to-liquid fraction in the suspension is determined.
Comparable Study of Electrical and Mechanical Properties in Plasma Sprayed Alumina Coatings
Authors: Tosaki T. , Kobayashi Y. , Ohta K. , Kitamura J. 
Published: March 2024

Abstract
In this work, alumina coatings are produced by air plasma spraying (APS) using dense powders ranging in size from 3 to 36 µm and one porous powder with an average particle size of 33 µm. Two spray systems were used, one rated at 40 kW, the other at 100 kW. The powders were applied to grit-blasted Al 6061 and low-carbon steel substrates. Coatings applied to Al 6061 using the high-power sprayer and 3 µm powder peeled off, likely due to thermal shock and mismatch. For all other coatings, the microstructure was examined by cross-sectional SEM, porosity was estimated via optical microscopy, and dielectric strength and volume resistivity were measured. Coatings formed from 3 µm powder were found to be dense with a mostly γ-phase crystal structure. Surprisingly, however, their volume resistivity was lower than that of more porous coatings with high amounts of α-phase. The findings show that, in the case of resistivity, spray equipment has a bigger influence than particle size, but with coating density, the opposite is true.
Investigation of a Pulsed Current Wire Arc Spray Process
Authors: Kirner S. , Schein J. , Forster G. 
Published: March 2024

Abstract
Much of the research being done in arc wire spraying deals with new nozzle geometries and secondary atomizing gas flows. This study, instead, focuses on pulsed current power. Spray trials are conducted using a conventional electric arc gun and an inverter that produces large current pulses with controlled amplitude and frequency. Droplet formation and detachment are monitored with a high-speed camera that records shadow images synchronized with current and voltage measurements. The images are processed into analog signals that are converted to the frequency domain and the Fourier coefficients are plotted, providing a relative measure of the influence of pulse frequency on droplet ablation. The results suggest that arc spraying can be improved using pulsed current power and that gas pressure and pulse time have greater influence than pulse frequency.
Structure and Properties of HVOF and Plasma Sprayed Ceramic Alumina-Chromia Coatings Deposited from Fused and Crushed Powders
Authors: Vuoristo P. , Niemi K. , Matikainen V. , Hyvärinen L. , Koivuluoto H. , Berger L.-M. , Scheitz S. , Shakhverdova I. 
Published: March 2024

Abstract
Different feedstock powder compositions of the alumina-chromia system were deposited on steel substrates by various methods, including conventional plasma spraying, three-anode plasma spraying, and HVOF. The powders used for plasma spraying had particle sizes of -38+10 µm and for HVOF spraying -25+5 µm and -25+10 µm. The coatings were evaluated by their microstructure, phase composition, and corrosion, wear, and electrical properties. The study shows that wear properties depend strongly on the spray process and that coatings obtained by HVOF spraying have dense structures and excellent wear behavior. Coatings produced by the three-anode plasma process, despite their higher porosity, were found to be harder than conventional plasma coatings and can be sprayed with higher feed rates. The coating properties do not appear to have a linear dependence on chromia content.
Structural Modifications on Material Surfaces by Thermal Nanoparticle Spraying and Microline Patterning
Authors: Kirihara S. 
Published: March 2024

Abstract
This study deals with two new material deposition processes in which raw materials are in the form of a thixotropic slurry. In one case, the slurry (Al2O3 nanoparticles in an acrylic resin) is misted into an arc plasma jet and sprayed on a stainless steel substrate. By varying the volume content of nanoparticles and slurry supply rates, investigators were able to achieve uniform droplets, resulting in fine Al2O3 layers free of microcracks and pores. In the other process evaluated, pure aluminum particles were dispersed in a photosensitive resin, producing a slurry that was spread on stainless steel substrates then patterned with a UV laser. The patterned metal particles were heat treated, creating iron-aluminide intermetallic phases through reaction diffusions. The microstructure and composition of the patterned lines are analyzed by SEM and XRD and surface stress distributions associated with a Hilbert fractal pattern are simulated via finite element analysis.
3D Wear Analysis of Thermal Spray Coatings
Authors: Tillmann W. , Luo W. , Selvadurai U. 
Published: March 2024

Abstract
This study investigates the wear resistance of WC-FeCSiMn coatings deposited on 3D surfaces by two-wire arc spraying. Wear behavior was evaluated by means of pin-on-disc testing, pin-on-rotating tube testing, and a method in which a robot arm moves a pin over test specimens with arbitrary surface geometries. Residual stresses were determined by incremental hole drilling and were found to have a dependency on substrate geometry. After wear testing, a 3D profilometer determined wear volume and coating surfaces were examined by SEM. The results indicate that wear resistance is strongly influenced by the geometry of the substrate.
Tungsten Carbide Deposition Processes for Hard Chrome Alternative: Preliminary Study of HVAF vs. HVOF Thermal Spray Processes
Authors: Lyphout C. , Kitamura J. , Sato K. , Yamada J. , Dizdar S. 
Published: March 2024

Abstract
This paper presents the results of a preliminary study comparing high-velocity oxyfuel and airfuel spraying for the deposition of tungsten carbide coatings as an alternative to electrolytic hard chrome plating. Two tungsten carbide powders with a Co matrix and two with a Co-Cr matrix were sprayed on steel substrates using commercial HVOF and HVAF equipment. The coatings obtained are evaluated by means of SEM and XRD analysis, microhardness and adhesion measurements, and corrosion and wear resistance testing. Detailed results are presented and discussed with emphasis on the role of carbide grain size, carbide contiguity, and binder mean free path. In general, HVOF coatings show significantly higher dry wear resistance, owing to the presence of coarser primary carbides from the initial coarser powder. HVAF coatings, on the other hand, exhibit lower porosity and finer well-distributed primary carbides, giving them an advantage in terms of sliding wear resistance.
External Powder Injection in Twin Wire Arc Spraying to Control the Coating Composition
Authors: Tillmann W. , Abdulgader M. , Hagen L. 
Published: March 2024

Abstract
This study investigates the potential of external powder injection for producing functionally graded coatings by twin wire arc spraying. In spray trials, the position of the injection port was altered along the spray axis and perpendicular to the arc and different powders and carrier gases were used. Real-time images were captured by a high-speed camera during spraying to detect correlations between gas flow rates, hard particle wetting, and atomization of the molten pool. The optimal location for injection was found to be dependent on the size and density of the powder and the flow rate of the carrier gas. In the case of embedding B4C in a Fe-based matrix, a strong metallurgical bond was formed, confirming that powder injection is a viable approach for controlling the composition of twin wire arc sprayed coatings.
Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD
Authors: Rezanka S. , Mauer G. , Vaßen R. 
Published: March 2024

Abstract
The durability of columnar TBCs produced by PS-PVD are strongly influenced by the compatibility of the metallic bond coat and ceramic topcoat. Studies have shown that a smooth bondcoat surface improves thermal cycling performance and that further improvements are possible by optimizing the formation of the thermally grown oxide layer. In this work, preheating and the deposition of the first coating layer are varied in order to adjust oxide growth. The results show that thermal cycling lifetimes can be more than doubled without a major increase in manufacturing time.
Controlling YSZ Abradable Erosion Performance by Optimizing Spray Parameters
Authors: Hawkins A. , Wellman R. , Craig M. , Nicholls J.R. , Laul K. , Shankar R. 
Published: March 2024

Abstract
This study investigates the effect of plasma spray parameters on the erosion rate of abradable seals used for clearance control in gas turbine engines. Coating samples were sprayed using YSZ powder containing polyester that was entrapped in the deposit then subsequently removed by heating. Test results show that erosion behavior is influenced by gun voltage and spray distance. A higher voltage results in a denser coating with a lower erosion rate. Increasing spray distance, on the other hand, increases porosity, which results in a higher erosion rate. Further analysis shows that the erosion rate is proportional to the inverse square of the spray distance and the square of the gun voltage.