bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Texturing as Interfacial Treatment for Enhancing the Material Behaviors—The Real Influence of the Laser Treatment
Authors: Costil Sophie , Convert Laura , Bourillot Eric , Pocholle Nicolas , François Manuel 
Published: May 2023

Abstract
Surface texturing is one of the most technologically appropriate laser surface treatment applications. Over the past few decades, texturing has emerged as an attractive surface engineering option and has been used by researchers to generate micro/nanopatterns on operating surfaces. This technique can create simple or complex patterns on component surfaces depending on their aesthetic or functional goals and without altering the overall properties. In addition, this non-contact process can be applied to hard-to-reach areas. Recently, laser surface texturing has been applied to improve the adhesion of contact surfaces. Several authors have demonstrated the impact and benefits of textured surfaces to achieve optimal adhesion of coatings and increase in-service behavior. Nevertheless, based on the laser-matter interaction phenomena, chemical and mechanical transformations of the surfaces can be noticed but are difficult to characterize. Indeed, the affected layers are of the order of a few hundred nanometers. Then, analyses must be performed with variable levels of resolution in order to analyze the structural, chemical and mechanical characteristics of the matter. To develop new applications of unconventional assemblies and improved adhesion of new materials, a control of these local modifications is required.
Automated Path and Trajectory Planning for Automated Repair of Damaged Components by Cold Spray
Authors: Lewke Marcel , Wu Hongjian , List Alexander , Gärtner Frank , Klassen Thomas , Fay Alexander 
Published: May 2023

Abstract
Cold spraying has emerged as a promising technique for the repair of metallic components. For controlled material deposition, manipulation of the cold spray gun is performed by industrial robots. Such robot-guided cold spraying provides flexible control and automation of the entire process. To enable effective and material-efficient material deposition at specified repair locations, this work proposes a method for automated planning of cold spray paths and trajectories. The method begins with the extraction of the volume to be filled by comparing the nominal and actual component. To produce the extracted volume, it is divided into suitable adaptively curved layers and converted into point clouds for path planning. The cold spray path is then converted into a trajectory by adding a suitable velocity distribution for the spray velocity to produce the required locally varying layer thickness. To validate the suitability of the path and trajectory, a simulation of the material deposition is performed. In addition, the implementation of the entire method is demonstrated by exemplary use cases. The results demonstrate that the proposed method enables successful automated path and trajectory planning, both contributing to the overall goal of automated repair of damaged components by cold spray.
Anisotropy of Mechanical Properties of DMD Build Inconel 738
Authors: Kovarik Ondrej , Cech Jaroslav , Kiziklioglu Egehan , Cizek Jan , Stittgen Tobias 
Published: May 2023

Abstract
Anisotropy of stress-strain behavior, fracture toughness, and fatigue crack growth rate was studied for Inconel 738LC alloy built by the Dynamic Metal Deposition technique (3DMD, a high-speed Directed Energy Deposition technique). The measured quasi-static properties, i.e. stress-strain and fracture toughness showed only subtle anisotropy, with no more than 10% differences found for different orientations. The fatigue crack growth rate was influenced by the specimen orientation more significantly (30% for fatigue crack growth threshold, up to 90% for Paris exponent and coefficient). This pilot study attributes the anisotropy of fatigue crack growth properties to material texture and the columnar grain geometry resulting from directional solidification. The obtained testing results indicate that 3DMD technology can produce materials with good mechanical and fracture properties even from materials considered as non-weldable such as In 738LC. The study provides a solid experimental base for further investigation of the fatigue crack growth mechanism relation to the material texture in 3DMD In 738LC.
Cost-Effective UHVOF-Sprayed Coatings for the Wear Protection of Valves
Authors: Bobzin Kirsten , Heinemann Hendrik , Burbaum Elisa , Schulz Marvin 
Published: May 2023

Abstract
Thermally sprayed WC/CoCr coatings are the most established coatings in the valve industry. However, due to the high wear resistance and as-sprayed surface roughness, the surface post processing costs are very high. Near-net-shaped fine powder coatings have the possibility to reduce the costs effectively. Due to the high specific surface to volume ratio of the powders, undesired phase transformations can occur during the spraying process. To avoid such phase transformations, the novel thermal spraying process Ultra-HVOF (UHVOF) is used in this study. An extensive parameter study is carried out on the influences of the process parameters on microhardness, porosity, as-sprayed surface roughness, phase composition and wear resistance. With suitable process parameters, near-netshaped and almost pore-free coatings can be applied. Compared to a conventional HVOF sprayed WC/CoCr coating, a wear reduction by a factor of three can be achieved in a pin-on-disktest against Al2O3 at a load of F = 15 N. Due to the pore-free and highly wear-resistant coatings, significantly thinner coatings can be used for the protection against corrosion and wear in valves. In addition, the required surface quality of the near-net-shape coatings can be achieved by polishing only. Thus, the novel UHVOF coatings represent a cost-effective alternative to conventionally used valve coatings.
Comparative Corrosion Behaviour of Cold Sprayed Titanium/Hydroxyapatite and Titanium/Baghdadite Composite Coatings in Simulated Body Fluid Environment
Authors: Kumar Avneesh , Chand Teekam , Kant Ravi , Singh Harpreet 
Published: May 2023

Abstract
Bioceramics deposition on medical devices is a widespread area of research for biomedical industries since such deposits can induce excellent chemical and biological properties to the devices. Thermal spraying has been a popular choice for developing coatings to enhance the mechanical, chemical, and biological responses of medical devices. However, the high heat involved during the thermal spraying of bioceramics limits their functionality. In this context, low processing temperature in cold spraying is believed to protect the bioceramics from degradation. However, depositing bioceramics using cold spray and achieving good mechanical properties are still challenging tasks because of their poor ductility. Therefore, bio metal matrix composites with reinforced bioceramics produced using cold spray are expected to give good mechanical, chemical, and biological properties. The present work presents deposition and microstructural characterization of titanium/hydroxyapatite (Ti/HA) and titanium/baghdadite (Ti/BAG) composite coatings by cold spraying. Furthermore, the comparative corrosion response of these coatings under a simulated body fluid environment is reported. The effect of laser remelting on microstructure and corrosion behavior is also discussed.
Cold Spray Nickel-Coated Aluminum Composite Powder Part I—Study on Microstructure of Coatings
Authors: Lu Xiaoliang , Zheng Zhaoran , Yuan Kang , Du Kaiping 
Published: May 2023

Abstract
NiAl coating can be used as bond coats for thermal barrier coatings (TBCs) with good ductility and excellent resistance against high temperature oxidation. In this study, nickel-coated aluminum composite powders were used to prepare NiAl intermetallic compound coatings on nickel-based superalloys using an air plasma spray (APS), high-velocity oxygen-fuel (HVOF) and cold spray (CS) processes. Different spraying parameters in the HVOF and CS processes were used to make different coating microstructures, and the coating prepared by the APS technique served as a control for the HVOF and CS processes. The microstructure and phase constitution of the coatings were studied using XRD, SEM and EDS. The results indicate that the deformation behavior of the NiAl powder was different under the different spraying parameters. Less defects of oxides and inclusions were observed in the CS coatings compared with the HVOF coatings.
Effect of Laser Power on Forming Quality and Crystallization of Amorphous Alloy Prepared by SLM
Authors: Chen Xing , Du Kaiping , Pi Ziqiang , Zheng Zhaoran 
Published: May 2023

Abstract
Amorphous alloys have attracted extensive attention due to their unique atomic arrangement and excellent properties. However, the application in practical engineering is seriously limited due to the size, crystallization and other problems. Laser additive manufacturing technology has the characteristics of high heating, cooling rate and point by point melting deposition, which provides a new idea for the preparation of amorphous alloys. Zr50Ti5Cu27Ni10Al8 amorphous alloy was prepared on the surface of pure zirconium substrate by selective laser melting technology. The composition and structure of the samples were characterized. The results show that the samples are mainly composed of amorphous phase, and the crystallization mainly occurs in the superimposed zone of heat affected zone. With the decrease of laser power, the area of crystallization zone and the number of crystallization particles decrease. However, if the laser power is too low, there will be non-fusion defects and cracks, which will seriously affect the forming quality and amorphous rate of amorphous alloy.
Investigation of Corrosion Behavior and Surface Characteristics of CoCr Alloy using Plasma-Sprayed HA/ZnO Reinforced Coatings for Biomedical Implants
Authors: Bansal Puneet , Singh Gurpreet , Sidhu Hazoor Singh 
Published: May 2023

Abstract
The enhancement of the surface characteristics and corrosion resistance of cobalt alloys is under continuous examination for its biomedical applications. In this work, the investigation of corrosion performance of cobalt alloy coated with HA and HA/ZnO reinforced powders using plasma spray technique revealed that on the continuous increase of ZnO reinforcement the corrosion resistance improved progressively. The increment in surface hardness and drop in surface roughness was examined with the rise in ZnO content. Each coated sample exhibits a hydrophilic property. According to SEM and EDX investigations, homogeneous distribution of HA/ZnO coatings and intact reinforcement of ZnO in pure HA powder was noticed. All of the coated specimens maintain their morphological integrity, ensuring excellent protection of the prepared samples. The obtained outcomes denote HA/ZnO reinforced coatings on CoCr alloy as a suitable combination of enhanced surface properties and excellent corrosion resistance for future bone implant practices.
Effects of Zr and Si Addition on Mechanical Properties of Al0.5CoCrFeNi High-Entropy Alloys
Authors: Bobzin Kirsten , Heinemann Hendrik , Erck Marvin , Schacht Andreas , Korte Benedikt , König Paul 
Published: May 2023

Abstract
Thermally sprayed heating coatings are a recent approach for temperature control in moulding tools. While there are material options in the lower temperature range up to T = 300 °C, new alloys have to be developed to improve the range of application. The Al0.5CoCrFeNi high-entropy alloy (HEA) with further addition of Zr and Si shows favourable electrical properties due to severe lattice distortion. The alloy development was carried out with Al0.5CoCrFeNiZrxSiy by arc melting. Thereby, the molar Zr content x was varied from 0 to 0.5 and the Si content y from 0 to 0.2. In order to evaluate the alloy’s prospective performance, the phase composition was studied by SEM with EDX and the fracture toughness was determined to estimate fracture properties, which are found to be a typical failure mechanism of heating coatings. The different HEA exhibit a typical dendritic microstructure with fcc dendrites and a bcc interdentritic phase. The hardness of the alloys increases with increasing bcc content, while the ductility decreases. With knowledge about the effects of Zr and Si on the electrical and mechanical properties, which are justified by the microstructure, Al0.5CoCrFeNiZrxSiy HEA can be tailored specifically towards the needs of individual heating applications.
Cold Spray Deposition of Aluminium 6061 Decorated with Al2O3 Nanoparticles
Authors: Marzbanrad Bahareh , Marzbanrad Ehsan , Jahed Hamid 
Published: May 2023

Abstract
This research presents a novel approach for producing metal matrix composite powders using a nanoparticle decoration technique. A 1wt% stable suspension of 30nm Al2O3 particles was decorated onto primary AA6061using a redispersion method. The resulting AA6061-1wt% Al2O3 composite powder was mixed in a rotary mixer for one hour and subsequently dried at 45°C. Scanning electron microscopy of the composite powder confirmed the successful material composition. The composite powders were then deposited onto an AA6061 substrate using a low-pressure cold spray system, with the coating quality, deposition efficiency, surface roughness, and hardness of the deposited materials analyzed. After heat treatment at 430oC, the role of the nanoparticles in hindering recrystallization was studied, with Orowan strengthening shown to be the main mechanism for preventing recrystallization and grain growth. This technique provides a promising alternative method for producing metal matrix composites and offers potential for further exploration of their properties and applications.
Composite Capsule Embedded Coatings Deposition using Thermal Spraying
Authors: Skaltsas D. , Papadopoulos C. I. , Sarafoglou Ch. I. , Ioannou P. , Andreouli D. , Georgiopoulos I. , Zotiadis C. , Korres D. M. , Vouyiouka S. 
Published: May 2023

Abstract
The study of self-lubricant coatings is a rapidly developing research field that is expected to address major issues arising from operation under high loads and thermal stresses of machine parts. It is of utmost importance that various critical tribological pairs such as crankshaft bearings, piston rings, etc. maintain their integrity, thus contributing to the engines efficient and reliable operation for long periods of time. Therefore, a choice of high-strength metals is required, with special treatments and/or coatings in combination with sufficient lubrication. In the present study, liquid lubricants encapsulated in poly(urea-formaldehyde) were incorporated in ceramic-metal matrices for the production of composite coatings by Atmospheric Plasma Spraying. Aspects concerning the survival of the capsules during their flight through the high temperature plasma flame, the maintenance of their integrity at impact with the substrate with high kinetic energy, their homogeneous dispersion within the coating mass, thermal spray deposition parameters adjustment and optimization are thoroughly discussed. Coating properties such as roughness, friction, adhesion strength, and wear behaviour were also investigated. Microstructural characteristics and friction-wear behaviour were found to be critical to the durability of coating.
Tab-to-Busbar Interconnects Formed by Dual Flow Cold Spraying
Authors: Maev Roman Gr. , Leshchynsky Volf , Strumban Emil , Pantea Mircea , Robert Brian J. , Brackett Thomas P. 
Published: May 2023

Abstract
Battery manufacturing involves a large number of individual cells arranged in modules configured within a battery pack and connected either in series and/or parallel to deliver the required power and driving range. Cells within a module are linked using a tab-to-busbar connection as the electrical interconnect. Therefore, a battery pack contains a plurality of tab-to-busbar joints, and each must provide low electrical resistivity connection to minimize losses that may reduce the effective performance of the battery. In this work, the Dual Flow Cold Spray (DFCS) process, a modification of low-pressure cold spraying, was used to form low resistivity Cu+10%Zn and Al+10% Zn tab-to-busbar interconnects. As test coupons, 0.8 mm thick copper (Cu) was used to represent the busbar while 0.3 mm thick aluminum and nickel coated copper foils represented the respective electrode tabs. Low resistivity joint interconnects (≈100 μΩ) with high adhesion strength (≈120 MPa) have been formed. The influence of busbar surface preprocessing on the resistivity of the tab-to-busbar joints has been studied.
Oxidation of In-flight Particles During HVAF—A Numerical Study
Authors: Diop Sokhna Awa Bousso , Moreau Christian , Nasti Aleksandra , Dolatabad Ali 
Published: May 2023

Abstract
Oxygen present in the High Velocity Air-Fuel (HVAF) process can react with the in-flight metallic particles and cause their oxidation. A grown brittle oxide shell on metallic microsize particles can reduce their deposition efficiency and impair the coating final deposited properties/microstructure. In the current study, the oxide growth of MCrAlY particles, where M stands for Ni and Co, during their flight in the HVAF process has been modeled using the particle tracking scheme. A comprehensive theoretical oxide layer growth background is presented and used to track the particle oxidation process. The oxidation development includes the Mott-Cabrera theory for very thin films, which is function of the particle surrounding temperature and oxygen partial pressure. The very thin film regime, applicable under a limiting thickness, is defined based on the electric field present across the growing oxide layer. As the electric field decreases with oxide thickness, the oxidation rate is determined by thermal diffusion. The obtained results provide a correlation between HVAF system design and surface oxidation phenomena while offering a clear description of different oxidation stages.
Influence of HVAF Process Parameters on In-Flight NiCoCrAlY Particle Oxidation and Corresponding Splat Characteristics
Authors: Thoutam A.K. , Lamana M.S. , Mahdavi A. , Liberati A.C. , Ben Ettouil F. , Moreau C. , Dolatabadi A. 
Published: May 2023

Abstract
The deposition of MCrAlX coatings (where M is Ni, Co, Fe, or a combination of these, and X is Y, Si, Ta, Hf, or a combination of these) via thermal spraying has acquired significant importance in industries such as aerospace, power plants, oil, and gas, etc. Among various thermal spray deposition techniques, high-velocity air fuel (HVAF) has shown a growing potential for the deposition of metallic powders which are sensitive to high-temperature oxidation during spraying. Thus, it is essential to understand the in-flight behavior of these metallic particles in the high-velocity, low-temperature HVAF flame. In this work, a NiCoCrAlY powder was sprayed using two sets of HVAF deposition parameters onto stainless steel substrates. In-flight particle diagnostic tools such as AccuraSpray were employed to understand the behavior of these spray particles. The deposited particles were comprised of partially molten particles and fully deformed splats. Samples with higher powder feed rates showed a primary coating buildup on the substrate surface. EDS plots revealed no traces of inflight particle oxidation but contained carbon residue due to the presence of unburnt hydrocarbons from the fuel-rich HVAF-M3 torch. This study provides a preliminary understanding towards the significance of deposition parameters on the in-flight particle oxidation behavior and splat deformation characteristics by HVAF spraying.
Study on the Attack of Molten Silicates to Thermal Barrier Coatings at Varying Service Temperatures
Authors: Martins Roberto Fernando , Couto Antonio Augusto , Camello Lima Carlos Roberto 
Published: May 2023

Abstract
Thermal barrier coatings have provided a revolution in the industry as they allow a higher operating temperature of equipment, improving the efficiency of gas turbines. However, one of the biggest challenges in terms of increasing the lifespan of TBC systems is the attack of fused silicates or simply CMAS (Calcium-Magnesium-Alumina-Silicate). CMAS are particles from the environment that can penetrate the TBC structure and cause delamination of the coating when exposed to high temperatures during thermal cycling. In this study, a plasma sprayed YSZ coating in the as coated and surface treated condition were given CMAS depositions from various preparation methods, and then subjected to thermal cycles at different evaluation temperatures and exposure times. The permeability of the ceramic layer and the penetration path of CMAS at different temperature levels were evaluated, as well as the penetration characteristics in relation to the microstructure of the ceramic layer. X-Ray diffraction and Scanning Electron Microscopy were used to characterize the applied CMAS and the penetration kinetics and conditions. Samples with longer exposure time had a considerable volume increase. The conditions to guarantee the formation of the silicate and its consequent wettability are also discussed.
High Entropy Alloy (HEA) Bond Coats for Thermal Barrier Coatings (TBCs)—A Review
Authors: Shahbazi H. , Vakilifard H. , Nair R.B. , Liberati A.C. , Moreau C. , Lima R S. 
Published: May 2023

Abstract
Due to the aggressive operation conditions of turbine hot sections, protective coatings are required to provide oxidation and hot corrosion resistance for superalloy components. Thermal barrier coatings (TBCs) are comprised of a ceramic top coat and a metallic bond coat (BC) and are typically used as thermal protection systems against these aggressive environments. Conventional BC materials are MCrAlX, with M being metals or alloys (e.g., Ni, Co or NiCo) and X being reactive elements such as Y, Hf, Ta, Si. Due to their strength, thermal stability, and oxidation resistance, high-entropy alloys (HEAs) have presented promise for use as BC materials in hightemperature applications. Owing to its cocktail effect, optimally chosen HEAs could help to enhance the hot corrosion resistance of BCs by forming a more continuous, dense, and uniform thermally grown oxide (TGO). Furthermore, HEAs could help to control the diffusion between the bonding layer and substrate in elevated temperature environments. This paper will discuss the thermodynamic, mechanical, and microstructural behaviour of HEAs. Furthermore, the selection and usage of HEAs as BCs will be explored and compared to conventional BCs in TBC systems.
High Entropy Oxides as Promising Materials for Thermal Barrier Topcoats—A Review
Authors: Vakilifard H. , Shahbazi H. , Liberati A.C. , Nair R.B. , Moreau C. , Lima R. S. 
Published: May 2023

Abstract
Multi-layered thermal barrier coatings (TBCs) are deposited on gas-turbine metallic components to protect them against high temperatures, oxidation, and corrosion. However, TBCs have limited working temperatures and lifetimes due to their material properties. Several approaches are being tested to increase TBC topcoats' phase stability and properties. Increasing entropy to stabilize phases is a concept introduced in 2004 and required decreasing the Gibbs free energy. Many high-entropy ceramics are being developed for structural and functional applications, and high-entropy oxides (HEOs) are promising TBC ceramics due to their unique characteristics. HEOs are single-phase solid solutions that contain five or more cations, usually a mixture of transition metals and rare earths. Due to the cocktail effect, the final material has a different behavior from its constituents, making it a viable method to improve the properties of traditional materials. Generally, high entropy materials are characterized by three additional phenomena: sluggish diffusion, severe lattice distortion, and high entropy. A review of possible improvements in the lifetime of TBC topcoats using different HEOs in terms of their composition, properties, and stability are presented here. Different HEOs are then examined and various thermophysical properties, high-temperature stability, and sintering resistance are discussed.