bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing and Suspension Plasma Spray Deposition of ZrO2-Based Ceramic Materials for Thermal Barrier Coatings
Authors: Camacho María Catalina Galeano , Ageorges Hélène , Muñoz-Saldaña J. 
Published: August 2024

Abstract
This work focuses on the processing and deposit by suspension plasma spraying (SPS) of ZrO2-based ceramic materials for Thermal Barrier Coatings (TBC's) applications. The system of interest is ZrO2-16mol%Y2O3-16mol%Ta2O5 (16YTZ). This ceramic has been reported to keep a non-transformable tetragonal phase (t'-phase), suitable to overcome the thermodynamic limits of the mostly used conventional 7-8wt.% yttria stabilized zirconia (YSZ). The research consists into evaluate the t'-phase stability and performance of the 16YTZ SPS coating. Synthesis of 16YTZ and, the evolution of the resulting microstructure in the dense ceramic and in the coating are a central part of the study. Sintering behavior in dense ceramics prepared from both precursor derived and milled powders is evaluated. Microstructural characterization by XRD, SEM and RAMAN spectroscopy of the as-deposited ceramic coating is presented and discussed.
COAXquattro: A Versatile High-Power Multi-Wire Laser Cladding Technology
Authors: Toma Filofteia-Laura , Hillig Holger , Kaubisch Marc , Shakhverdova Irina , Seifert Marko , Brückner Frank 
Published: August 2024

Abstract
Laser cladding shows an increasing interest to apply high-quality tailored surface coatings, as well as 3D-deposits for repair and additive manufacturing of metallic parts. The industry is requesting powerful technologies that maintain the quality advantages of the laser technology, but also make the process more productive, as well as time and cost efficient. At Fraunhofer IWS a Laserline fiber-coupled diode laser of 20 kW power has been employed for over a decade to develop competitive coating solutions. The deposition rates achieved with this technology are comparable to those of common PTA technique, while at the same time bringing significant advantages in terms of reduced heat affected zone, distortion and savings in material resources.
Exploring the Crack Propagation Behavior in Suspension Plasma Sprayed Thermal Barrier Coatings: An In-Situ Three-point Bending Study in Scanning Electron Microscope
Authors: Amer Mohamed , Curry Nicholas , Arshad Muhammad , Hayat Qamar , Janik Vit , Nottingham Jon , Bai Mingwen 
Published: August 2024

Abstract
In this study, the in-situ technique was used to observe crack formation and growth in multilayer suspension plasma spray (SPS) thermal barrier coatings (TBCs). Utilizing synchronized three-point bending (3PB) and scanning electron microscopy (SEM), coupled with digital image correlation (DIC), we provide real-time insights into strain field dynamics around cracking zones. Bending-driven failure was induced in both single and composite-layer SPS coatings to investigate the crack behavior in these columnar-structured multilayer TBCs. The real-time observations showed that columnar gaps can facilitate crack initiation and propagation from the coatings' free surface. The composite-layer SPS coating exhibits lower susceptibility to vertical cracking than the single-layer SPS coating, possibly due to the presence of a gadolinium zirconate (GZ) dense layer at the coating's free surface that enhances the bonding strength within the coating's columnar structure. The splat structure of the bond coat (BC) layer contributes to the crack path deflection, thereby potentially improving the SPS coating' fracture toughness by dissipating the energy required for crack propagation. Moreover, it was revealed that grit particles at the BC/substrate interface seem to promote crack branching near the interface, localized coating delamination, and serve as nucleation sites for crack development. Hence, optimizing the grit-blasting process of the substrate before BC layer deposition is crucial for minimizing the possibility of crack formation under operational conditions, contributing to enhanced durability and prolonged lifespan. This study underscores the critical role of in-situ observation in unravelling the complex failure mechanisms of multi-layered coatings, paving the way for the design of advanced coatings with enhanced structural complexity and improved performance for more extreme environments.
Performance of Thermally Sprayed Inconel Coatings in Erosion-Corrosion Conditions of Biomass-Fired Boilers
Authors: Verma Rajan , Kaushal Gagandeep 
Published: August 2024

Abstract
In biomass boilers, corrosion is a prevalent concern that arises at high temperatures. This is mainly because the fuels consumed in these boilers have a high alkali, chlorine, and other molten salt content that has occasionally led to material depletion, leaks, and unforeseen plant shutdowns. Applying protective coatings using thermal spray techniques is a practical answer to this issue. The current work focused on applying powders of Inconel 625 and Inconel 718 to boiler steel using a high-velocity oxy-fuel spraying method. The samples after coating deposition were subjected to the conditions of a biomass-fired boiler for 15 cycles to study the performance of the coatings in a real environment. The decrease of thickness over time was used to evaluate the erosion-corrosion process. Various characterization techniques were used to examine the as-sprayed and eroded-corroded specimens. The X-ray diffraction (XRD) technique was utilized to analyze the phases, while the surface characteristics of powders, coatings, and samples exposed to erosion-corrosion were investigated through scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS). When exposed to the actual boiler environment, the findings showed that Inconel 625-coated steel performed better than Inconel 718-coated steel.
Plasma Spraying—From Single to Multiple Electrodes
Authors: Mauer Georg 
Published: August 2024

Abstract
It is well known that legacy one-cathode/anode thermal spray guns are sensitive to aging. One reason is the large power density in particular at the arc roots on the cathode tip and the anode wall. Anode wear was studied in showing that it leads to a thinner boundary layer and a reduced motion of the arc root, which increases the local thermal load. This also results in a voltage drop, and thus in power level reduction if the power source is operated in a constant current mode. In this case, it is widely practiced to increase the secondary plasma gas flow, which, however, can only be of some help.
Properties of Novel Partially Amorphous Fe-Based Thermal Barrier Coatings under the Influence of Cryogenic Temperature and Hydrogen
Authors: Hauer M. , Möhrke L. , Biswal P. , Brätz O. , Gericke A. , Allebrodt B. , Henkel K.-M. 
Published: August 2024

Abstract
Previous own works revealed that novel partially amorphous Fe-based alloys have a combination of proper-ties that are beneficial for the application in liquid hydrogen (LH2) tanks, viz low thermal diffusivity, little porosity, and good adhesion. The influence of cryogenic temperatures or hydrogen on coating tensile strength, on the other hand, has not been investigated yet for this material. However, this is crucial for the long-term durability of the coatings under hydrogen and other alternative fuels. Thus, in this work, tubular coating tensile (TCT) tests were performed at room temperature and cryogenic temperatures. In addition, hydrogen charging was carried out to identify a possible regime that is sufficient for TCT tests under the influence of hydrogen. Subsequently, the fracture surfaces were evaluated analytically, optically and profilometrically. Under cryogenic conditions, a significant increase in tensile strength and a finer structure of the fracture surfaces was observed.
In-Situ SEM Observation of Mechanical Failure of Hybrid Plasma Spray Coatings
Authors: Musalek Radek , Tesar Tomas , Minarik Jakub , Genois Romain , Dudik Jonas 
Published: August 2024

Abstract
Hybrid plasma spraying combines deposition of coatings from coarse powders and liquids (suspensions or solutions) so that the benefits of both routes may be combined. In this study, failure evolution of early-stage thermal barrier coatings (TBCs) with hybrid YSZ-YSZ and YSZ-Al2O3 top-coats deposited by hybrid water/argon-stabilized plasma torch was evaluated. In-situ bending experiment was carried out in SEM to assess potential influence of the secondary miniature phase addition on the coating failure during mechanical loading. Adapted high-resolution open-source strain-mapping code GCPU_Optical_flow was used to track evolution of the local coating failure. For the tested coatings, addition of miniature phase did not weaken the hybrid coating microstructure as the crack propagation was practically insensitive to the presence of the secondary phase and dissimilar splat boundaries. Main micromechanisms of the top-coat failure were thus splats cracking, loss of cohesion (splat debonding), and mutual splat sliding.
A New Approach for the Application of Highly Reactive Metals
Authors: Rodriguez Diaz M. , Szafarska M. , Gustus René , Möhwald K. , Maier H. J. 
Published: August 2024

Abstract
For the application of thermally sprayed titanium coatings, the high oxygen affinity and tendency to nitride formation in the presence of nitrogen represents a major challenge. Consequently, thermally sprayed titanium coatings are usually applied by cold gas spraying, vacuum plasma spraying and shrouded spraying processes. Nevertheless, the formation of oxides cannot be completely avoided with these methods. The pre-sent study demonstrates an alternative coating strategy for the application of oxide and nitride free thermally sprayed titanium coatings. Thereby, the previous limitations are overcome by transferring the coating process into a silane-doped argon gas environment to achieve an extremely low oxygen and nitrogen partial pressure. Thus, the created titanium coatings are oxide and nitride free and have an extremely low porosity. Moreover, by transferring of the corundum blasting process to this environment, the native oxide layer on the substrate surface can be removed and its reformation is suppressed. This results in full material bonding conditions with extremely high adhesive tensile strengths.
Physical Mechanisms in Plasma Spray Processing of Suspensions
Authors: Chergui A. , Lebot C. , Rat V. , Mariaux G. , Denoirjean A. 
Published: August 2024

Abstract
Suspension plasma spraying (SPS) is increasingly studied to produce finely structured coatings with dense and columnar microstructures for promising thermal barrier coatings especially in aerospace application. However, this process involves many parameters and complex phenomena with large spans of time and space scales in many physical mechanisms, like droplet break-up, liquid droplet evaporation, and various physical phenomena occurring within the suspension droplet, making it difficult to master. Especially, understanding the interactions of liquid drop submitted to plasma with the submicronic suspended particles is essential for material process optimization and control. For SPS understanding, a meaningful modelling of suspension treatment requires a prior analysis of these physical mechanisms and their characteristic times. This study details the different phenomena, their significance and characteristic timescales as well as the selection of the main governing forces acting between the different continuous and discrete phases (plasma, liquid, submicronic particles). We explore associated mechanisms: droplet breakup, carrier liquid evaporation, convective mixing and submicronic particle diffusion within the droplets. These mechanisms involve mass and heat transfer, that should condition particle agglomeration morphology before melting.
Investigation on Oxidation and Interdiffusion in the Systems of Aluminiferous Coatings and Superalloys
Authors: Sun Xiaoyu , Moverare Johan , Li Xin-Hai , Peng Ru Lin 
Published: August 2024

Abstract
A novel model for coating design was proposed in this research, by considering both oxidation property and interdiffusion effect, corresponding to two factors of the Cr:Al activity ratio and the potential of Al, respectively. To verify this model, oxidation tests of coated superalloys were performed at 1000 ° C for up to 5000 h. The test results indicated a strong positive correlation between GPDZ and Al potential and a clear negative correlation between oxidation kinetics parameter kp and Cr:Al activity ratio. Our research opened up new ideas for the coating design.
Fast and Non-Destructive Mechanical Characterization of Coatings from Thermal Spraying and Laser Cladding: Automated Surface Acoustic Wave Spectroscopy as a New Tool for Quality Control and Research
Authors: Zawischa Martin , Makowski Stefan 
Published: August 2024

Abstract
Laser-induced surface acoustic wave spectroscopy (LISAWS) allows quick and non-destructive access to elastic properties such as the Young's Modulus of coatings, surfaces and surface-near bulk materials. Furthermore, the mechanical weakening due to cracks and pores can be evaluated, as they influence the propagation of surface waves as well. Therefore, the method is a quick and powerful tool for surface characterization and can be found today in research and development, quality control and as a precise reference method. The short measuring time of the LISAWS measurement allow the distribution of the effective Young's modulus over the coated surface to be determined with a high accuracy. For this purpose, a LISAWS measurement system was automated to allow for processing of a larger amount of samples and fast mappings. The investigated coating materials were thermally sprayed Al2O3 insulation coatings and WC-reinforced 316L steel coatings on brake discs produced by laser cladding. For the Al2O3 coatings, the correlation of the Young's modulus and its areal distribution is shown for different process parameters, such as spray gun movement direction or spraying distance, and compared with results from pull-off tests. For the WC/316L coated brake discs, the distribution of the wave velocity over the coated surfaces or the two coated sides of different discs with varying coating qualities is used to assess the coating quality and homogeneity.
Characterizing Deformation by Positron Annihilation Spectroscopy: Cold Spray vs. High-Pressure Torsion
Authors: Cizek Jan , Medricky Jan , Stefanik Filip , Lukac Frantisek , Melikhova Oksana , Cizek Jakub 
Published: August 2024

Abstract
Cold spray (CS) is a progressive method for the deposition of metals and alloys whose principles involve considerable plastic deformation of the produced material at extreme strain rates. Positron annihilation spectroscopy (PAS) is an analytical technique capable of studying deformation on the atomic scale level, even in extremely deformed materials. In our study, the PAS method was used to characterize the deformation character at the lattice level and quantify the open-volume defects in four cold sprayed metals: Al, Cu, Ni, and Ti. As counterparts, bulk samples of these materials with ultrafine-grained structures were also produced by high-pressure torsion (HPT), a process exceeding cold spray in the total deformation, but having several orders of magnitude smaller strain rates, and by a traditional cold rolling process. The results show that the CS and HPT processes lead to the formation of similar lattice defects (dislocations and vacancy clusters), and both exhibit significantly higher dislocation densities than conventionally cold-rolled materials. Further, the vacancy clusters present in CS and HPT materials were not present in the rolled counterparts due to the lower vacancy production rate.
A Micro-Spectroscopic Approach to Characterizing Residual Stresses and Subsurface Modifications Due to High-Speed Collision During Cold Spray Deposition of Metals on Glass Substrates
Authors: Elkholey Ali K. , De Ligny Dominique , Raoelison Rija Nirina , Verdy Christophe , Bertrand Pierre , Langlade Cecile 
Published: August 2024

Abstract
By approaching the glass transition temperature it was possible to realize well quality metallic coatings on two different glasses using Cold Spray deposition, CS. A roughness is introduced on the glass surface and is proportional to the energy deposited. Using the thermal pressure memory effect of glass, Raman spectroscopy mapping allowed determining that the CS introduced a strong heterogeneity of the glass substrate characterized by zones with different cooling rate and residual stress. Using a simplified Eshelby's inclusion approach, it is demonstrated that the residual stress can be in first approximation explained by the introduction of local density fluctuation induced with high cooling rate of micrometric regions related with the impact of the deposited metallic particles.
Towards an Integrated Modular Cold Spray Additive Manufacturing System
Authors: Li Wenbo , Wu Hongjian , Liu Shaowu , Liao Hanlin , Costil Sophie , Deng Sihao 
Published: August 2024

Abstract
Cold spray additive manufacturing (CSAM) is an emerging process that has garnered significant attention from researchers due to its unique advantages. These include higher deposition rates, no need for a protective atmosphere, and the ability to connect or combine dissimilar materials. While CSAM allows for near-net-shape fabrication of workpieces, the accuracy and properties of the final products often fall short of user requirements. Furthermore, there is an urgent need to develop a generalized manufacturing strategy for workpieces with complex geometries. It appears that integrating various processes throughout the entire manufacturing workflow, from design to delivery, could address these challenges. However, few researchers have explored this area. To fill this gap, this study presents an integrated modular CSAM system designed for efficient and flexible workpiece fabrication. The system comprises two main components: software for modeling and simulation, and hardware for precise fabrication, each containing multiple modules. These modules do not operate independently but are coupled through direct or indirect decentralized and event-driven physical links. The system described in this paper offers a generalized strategy for precision manufacturing of workpieces using CSAM, potentially advancing the field and addressing current limitations in accuracy and versatility.
From Anticosti Island's ‘Deep Time’ to A Cold Spray Additive Manufacturing Art Creation
Authors: Nastic A. , Jodoin B. , Fitzgerald C. , Desaulniers S. , Pouliot L. , Caio F. , Macdonald D. , Duval A. , Dubois G. , Tessier V. , Etienne C. 
Published: August 2024

Abstract
Thermal spray (TS) technology has attracted the attention of numerous industrial sectors due to its apparent simplicity and versatility. It has been used across the world for over 80 years in the conservation and creation of art. Despite the creativity involved in the creation of an art piece, the TS artistic endeavors are limited and insufficiently explored. Unique material combinations, usually not observed in conventional engineering applications, can be achieved with TS technology. Although the material amalgamation possibilities are infinite, their combined deposited characteristics, interfacial compatibility and color palette require further study. In this work, the fields of photography, image processing and TS are combined to produce a large art-piece using the cold gas dynamic spray (CGDS) process. Aluminum, zinc, nickel, alumina, steel and titanium alloy powders are sprayed to replicate in three-dimensions a photograph of a crinoid from the Silurian period found on the Anticosti Island, located in the Gulf of St. Lawrence in Canada. The numerous steps required to produce the artistic 3D piece, namely numerical segmentation of the photograph, conversion to a computer-assisted design (CAD), manufacturing of steel masks and CGDS deposition of the selected powders to reach the sought color palette are described. Powder deposition efficiency, material compatibility and microstructural characteristics are analyzed. and the resulting art piece is presented.
Hard-Facing Coatings for Agriculture Tools
Authors: Möhrke L. , Hauer M. , Biswal P. , Gericke A. , Henkel Knuth-Michael 
Published: August 2024

Abstract
Whenever farming tools are used, the focus is on wear resistance. As the wear rate differs with local soil conditions, the progress of wear and thus the time for tool change is difficult to identify. Hence, component failure and breakage as well as the unknown retention of components or parts thereof in the field are possible undesirable consequences. This demands not only a better wear-resistant coating, but also a wear limit indicator to determine the time for tool change more precisely. This helps in reducing the fuel consumption and increasing the quality of soil. Therefore, the aim of this study is the development and application of a coating system with increased wear resistance compared to original OEM parts (Original Equipment Manufacturer) and integrated optical wear indication. Preliminary own tests demonstrated that arc-sprayed hard-facing coatings can increase the wear limit. Thus, in the current work two different types of thermal sprayed coatings are analyzed with regard to their wear resistance behavior. After positive wear test results, field testing on farmland was carried out. Further investigations concerned microstructure, optical as well as profilometry surface analyzes.
Tribology of Self-Fluxing Ceramic Coatings Prepared Using External Feeding Hybrid Plasma Spraying
Authors: Tesar Tomas , Musalek Radek , Lukac Frantisek , Walter Jan , Cvrcek Ladislav , Cech Jaroslav 
Published: August 2024

Abstract
Hybrid plasma spraying can be utilized to deposit novel coating microstructures by combining the simultaneous injection of a dry coarse powder and a liquid feedstock into the plasma jet. Using this approach, the coating microstructure contains both coarse powder-made splats and a dispersion of fine liquid-made splats. Furthermore, the so-called external feeding hybrid method allows the incorporation of fine particles of materials susceptible to decomposition at high temperatures thanks to the by-passing of the hot plasma jet and deposition of the temperature-sensitive material directly onto the coated surface from a suspension. In this study, microstructures of ceramic coatings with embedded self-fluxing sulfides were studied and the wear resistance of the system was evaluated using the dry sliding pin-on-disc method.