bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of YSZ Thickness on the Thermal Cyclic Fatigue Performance of Gadolinium Zirconate/YSZ Double Layered TBCs
Authors: Mahade Satyapal , Markocsan Nicolaie , Curry Nicholas 
Published: October 2022

Abstract
Thermal barrier coatings (TBCs) play a vital role in allowing the gas turbine engines to operate at high temperatures. With higher operating temperatures (&gt;1200°C), the standard TBC material, 7-8wt. % Yttria Stabilized Zirconia (YSZ), is susceptible to CMAS (Calcium Magnesium Alumino Silicates) degradation and undesirable phase transformation. New TBC materials such as gadolinium zirconate (GZ) have shown to be capable of overcoming the challenges faced by YSZ. However, GZ has inferior fracture toughness relative to YSZ. In this work, three double layered TBC variations with different GZ and YSZ thickness respectively (400GZ/100YSZ, 250GZ/250YSZ and 100GZ/400GZ respectively, where the prefix numbers represent thickness in ìm) were produced by suspension plasma spray (SPS) process. In all the three double layered TBC variations, the overall TBC thickness with GZ as the top layer and YSZ as the base layer was kept the same (500 μm). The objective was to investigate the influence of YSZ thickness on the thermal cyclic fatigue performance of GZ/YSZ double layered TBC. The as sprayed TBCs were characterized by SEM, XRD and porosity measurements and later subjected to thermal cyclic fatigue test at 1100°C. It was observed that the GZ/YSZ double layered TBC with lowest YSZ thickness (400GZ/100YSZ) showed higher thermal cyclic lifetime whereas the TBC with thicker YSZ layer (100GZ/400YSZ) showed lowest thermal cyclic fatigue lifetime. The failure analysis of the thermally cycled TBCs revealed similar failure modes, i.e. spallation of the top coat due to horizontal crack propagation within the thermally grown oxide (TGO). Furthermore, the ceramic top coats in all the three TBC variations after failure showed the widening of column gaps.
Mechanisms on Vacuum Heat Treatment Promoting the Adhesion Strength of Thermal Sprayed Metallic Coatings
Authors: Meng Guo-Hui , Zhang Bang-Yan , Liu Hong , Xu Tong , Yang Guan-Jun , Li Cheng-Xin , Li Chang-Jiu 
Published: October 2022

Abstract
In this study, the mechanisms responsible for enhancing the adhesion strength of thermally sprayed metallic coatings subjected to vacuum heat treatment were investigated using atmospheric plasma sprayed (APS) CoNiCrAlY coatings as an example. The formation of metallurgical bonding between the coating and the substrate, which determined the increase in the adhesion strength of the coatings, was studied by analyzing the effect of morphological changes of the oxide film in the coating. The results showed that during the vacuum heat treatment process, the oxide film formed during the coating deposition gradually broke down and subsequently shrank into round oxides. After vacuum heat treatment, the adhesion strength of the coating improved significantly, and there was a positive nonlinear relationship between the treatment time and the adhesion strength. The increase in the adhesion strength was caused by the formation of metallurgical bonding between the coating and the substrate. However, the prerequisite for the formation of metallurgical bonding was that the oxide film had to break during the vacuum heat treatment process. A thermodynamic 2D model based on the thermal grooving theory was proposed to explore the essential conditions for the breaking and shrinking of the oxide film.
Cold Spraying of Mixed Sn-Al Powders onto Carbon Fiber Reinforced Polymers
Authors: Liberati Andre , Che Hanqing , Yue Stephen , Vo Phuong 
Published: October 2022

Abstract
Pure metal coatings have successfully been cold sprayed on to carbon fiber reinforced polymers (CFRPs) in previous studies at McGill University. As a means to improve coating conductivity for lightning-strike protection (LSP) purposes, coatings with mixed metal powders were sprayed. There is also the possibility of improving the deposition efficiency (DE) since single component tin coatings previously had a maximum DE of only 20%. The studied coatings were based on a mix of tin and aluminum powders, the latter being a metal commonly used in the aerospace industry for its lightweight properties. The different coatings were characterized and compared to results on pure tin coatings and on mixed Sn-Cu and Sn-Zn coatings. The DE was measured for different conditions and compared to those of previous studies. Mixing tin and aluminum powders is discussed and various mechanisms related to cold spraying mixed powders on CFRPs are explored.
Anisotropic Response of Cold Sprayed Copper Deposits
Authors: Yang Kang , Li Wenya 
Published: October 2022

Abstract
Cold spray (CS) is characterized as a solid-state process of high deposition efficiency for metallic coatings as well as additive manufacturing of metals. However, due to high velocity impact and extensive deformation of particles during CS, the as-received coatings or deposits may present anisotropic characteristics which could influence the performance of deposits. Hence this study aims to investigate the anisotropic behaviors of CS copper deposits in a systematic way. The microstructure and micromechanical properties of the deposits both in the cross-section (v-face) and in the parallel plane to the surface (p-face) were characterized. Tensile tests were performed at various loading angles with respect to the nozzle moving direction in the p-face. It is revealed that there exist strong microstructural and mechanical anisotropies in CS deposits. Different interparticle interaction results in more severe particle impact deformation in v-face than p-face, with larger elastic modulus and microhardness values. The tensile tests show an unexpected anisotropy in both ultimate tensile strength and elongation, with the highest performance occurring at the angle of 20°. The in-plane tensile anisotropy could be attributed to the parallel multiple passes. Therefore, a novel weave-spraying method was proposed, which can greatly reduce the tensile anisotropy of CS deposits.
Investigation of Particle/Substrate Bonding Between Copper Powder and Different Substrates in Cold Spray
Authors: Chen Chaoyue , Xie Yingchun , Xie Xinliang , Deng Sihao , Liao Hanlin , Huang Renzhong , Ren Zhongming 
Published: October 2022

Abstract
In this work, the bonding mechanism between Cu particle and substrates of Mg, Cu and stainless Steel (SS) was investigated by the direct observation of bonding interface on detached particle and substrate crater. In the cases of Cu/Cu and Cu/SS, dimple-like fractures were found on the detached Cu particle and substrate crater for the first time. Accompanying with EDS line scan and mapping results, such dimple fractures can be considered as the signs of strong metallurgical bonding. However, the bonding interface in case of Cu/Mg is smooth without signs of metallurgical bonding. Finite element analysis results revealed a ring of high contact pressure zone on the surface of particle and substrate, which is exactly the place where metallurgical bonding was observed. It can suggest that the high contact pressure zone is the dominant factor for the formation of metallurgical bonding on the oxide-free interface. The evolution of maximum contact pressure in different cases shows that the substrate hardness plays an important role during the single particle bonding. The present study provides a profound insight into the bonding mechanism of a single cold sprayed particle, which can give the guidance to the full deposition of cold sprayed coating.
An Optical Emission Spectroscopy Study of Plasma-Precursor Interactions in Solution Precursor Plasma Spray
Authors: Menneveux Jérôme , Veilleux Jocelyn 
Published: October 2022

Abstract
In this work, optical emission spectroscopy is used to study plasma-liquid precursor interactions in a plasma spray process. A mapping of the plasma jet is performed with a bundle of seven optical fibers while injecting various liquid precursors. Two suspensions containing a titania (TiO2) powder in different solvents and one solution containing titanium butoxide are analyzed. For each precursor, the evolution of both temperature and spectral line intensities along the plasma jet are observed. Comparing these results brings a new understanding of the precursor decomposition inside the plasma, while the noted contrasts between water and ethanol as solvent, and between the use of a powder and that of an alkoxide as a source of titanium, help to assess the effect of these parameters on the plasma spray process.
On the Premise of Polymer Coating Modelling for Cold-Spray Process
Authors: Bernard C.A. , Ogawa K. , Cavaillé J.-Y. , Lame O. , Ravi K. , Deplancke T. 
Published: October 2022

Abstract
Cold-spray process (CS) showed suitable properties to weld together compatible and incompatible materials. Since it has been intensively studied as additive technique using metallic powders on metallic surfaces, and only recently with polymeric powders, we compare, in a very preliminary attempt, simulated data of the impact of an aluminum particle onto aluminum substrate, with the case of an ultra-high molecular weight polyethylene (UHMWPE) particle on the same substrate. It is noteworthy that such polymer cannot be processed by classical means (extrusion, injection molding, etc.), and CS appears to be very promising as alternative technique to powder sintering (applicability on large surface area, surface curvature).
Characterization of Powder-Precursor HVOF-Sprayed Al2O3-ZrO2 Coatings
Authors: Kiilakoski Jarkko , Puranen Jouni , Koivuluoto Heli , Vuoristo Petri 
Published: October 2022

Abstract
Enhancing mechanical and chemical properties of ceramic coatings is a perpetual objective in the thermal spray community. Utilizing either novel feedstock or thermal spray process modifications are the most plausible ways to achieve enhancements such as improved corrosion resistance or damage tolerance. Quasi-plasticity and ultrahigh yield strength can be obtained with ceramic coatings by increasing the number of nanoscale features in the as-sprayed coating. Currently, thermal spraying using liquid feedstock can produce coatings with very fine microstructures, either by utilizing submicron particles in the form of a suspension or through in-situ synthesis. The focus of this work was to obtain a bimodal microstructure by using simultaneous powder-precursor HVOF spraying. Nanostructure was achieved from YSZ and ZrO2 solution-precursors and the microstructural features were obtained from using a conventional Al2O3 spray powder. The microstructure of the coatings revealed some clusters of unmelted nano-sized ZrO2 embedded in a generally dense matrix of Al2O3. The phase compositions consisted of γ- and α-Al2O3 and tetragonal and monoclinic ZrO2 with the former being dominant. The mechanical strength of the coatings was evaluated by Vickers hardness test and cavitation erosion. The addition of the nanostructured ZrO2 into the coating was found to deteriorate the structural cohesion of the coatings, leading to degraded durability when compared to a conventional HVOF-sprayed Al2O3-coating.
Deposition of Multiphase Coatings from Liquid Feedstock using Hybrid Water-Stabilized (WSP-H) Plasma Torch
Authors: Tesar Tomas , Musalek Radek , Medricky Jan , Cizek Jan , Lukac Frantisek , Chraska Tomas 
Published: October 2022

Abstract
Recently, hybrid water-stabilized plasma technology (WSP-H) was successfully adapted for the deposition of tailored single-layer coatings using liquid feedstocks (i.e. suspensions or solutions). High enthalpy of the WSP-H torch enables efficient deposition of the coatings with high feed rates and novel microstructures. In this study, concurrent and consecutive deposition of alumina-titania, YAG and YSZ suspensions was carried out in order to demonstrate the possibility of depositing multiphase coatings having layered, intermixed or even functionally graded (FGM) microstructures. Successful deposition of all three types of microstructures proves the feasibility of further development of the next generation of suspension plasma-sprayed coatings using WSP-H technology.
New Material Concepts for Thermally Sprayed Hydrodynamic Bearings
Authors: Bobzin K. , Öte M. , Königstein T. , Wietheger W. , Schröder T. , Jacobs G. , Bosse D. 
Published: October 2022

Abstract
Hydrodynamic bearings have to fulfill different requirements, depending on the operating conditions. Yet, conventional hydrodynamic bearings could not be used in critical operating conditions such as permanent start / stop operations. This is the reason why rolling bearings are currently used for frequent starting operations and low circumferential velocities, as they occur in wind turbines. In order to operate hydrodynamic bearings in a fail-safe manner even under these increased requirements, new bearing materials are needed. Within this study two new bearing material concepts are developed and deposited by thermal spraying as coatings to interact in this tribological system. On the one hand, matrix materials containing friction-reducing solid lubricants and on the other hand, multilayer systems, which can be used in as-sprayed condition, are investigated. The aim of both concepts is to improve the operation properties under critical conditions. The coating concepts are therefore tested on a modified high-load ring-on-disc tribometer and are compared to a reference plain bearing material produced by conventional casting. In this way, it is shown whether these new concepts can meet the requirements of slow-moving and highly loaded hydrodynamic bearings.
Development of Protective Thermal Spray Coatings for Lightweight Al Brake Rotor Discs
Authors: Poirier Dominique , Legoux Jean-Gabriel , Irissou Eric , Gallant Danick , Jiang Jimmy 
Published: October 2022

Abstract
This paper reports on the performance evaluation of stainless steel (SS) thermal spray coatings aimed at shielding lightweight aluminum (Al) brake rotor disks from excessive heat and providing an adequate tribological surface in contact with brake pads. Coating wear, corrosion and heat resistance performances were evaluated using pin-on-disk, cyclic corrosion tests and thermal cycling using a custom laser rig, respectively. Arc spray optimized coatings displayed lower or equivalent wear rates when compared with the baseline gray cast iron disks, with similar frictional behavior. However, arc spray coating exhibited low adhesion which limits the maximum coating thicknesses achievable and leads to early coating spalling after about 1000 thermal cycles. Arc sprayed coatings also corroded and delaminated under corrosion tests. Optimized cold spray coatings present high corrosion resistance and could resist above 10,000 thermal cycles without spalling. However, cold spray coatings exhibit wear rates at least 4 times those of the cast iron. Taking advantage of both types of coatings, it was found that the production of a duplex coating made of a cold spray bond coat and an arc spray top coat could meet the requirements for protecting Al disks, with near 50% weight reduction.
GROB Advances in Thermal Spray Technology Development for Cylinder Bore Applications in Mass Production
Authors: Gand Bernhard , Wörfel Andreas 
Published: October 2022

Abstract
In times of duality of combustion engine and electric motor propulsion the automotive industry is developing both powertrain systems. Weight reduction and enhancement of efficiency plays a vital role in the conception of combustion engine for passenger cars. The thermal spray technology therefore is trend-setting as it achieves both aims. GROB-WERKE have, as reported previously, developed and integrated their GTS (GROB Thermal Spray) process for steel deposits in aluminum cylinder bores into their production lines. Further effort was now made to improve performance and versatility. The application of measurement and simulation technics hand in hand with extensive experimental investigation in spray deposit diagnostics as well as plasma and particle jet analysis led to highly developed and advanced deposit microstructure and cylinder bore topographies. Complex and extensive CFD (Computational Fluid Dynamics) simulation of the gas and particle flow gave the thermal spray process the highest performance, efficiency and product cleanliness.
High Velocity Oxygen Fuel Spraying of Nanostructured Hydroxyapatite on Magnesium Alloy Substrate for Biomedical Application
Authors: Mardali Marzieh , Salimijazi Hamidreza , Karimzadeh Fathallah , Coyle Tom 
Published: October 2022

Abstract
Magnesium light weight alloys are currently being studied as implants due to their biodegradability. However, its applications are limited by high rate hydrogen evolution during corrosion. Coating on this substrate is one of the ways to reduce the rate of corrosion and increase the life of this type of implant. Hence, hydroxyapatite (HA) was coated on the substrates by using high velocity oxy- fuel (HVOF) spraying. The main purpose of such coatings is increasing bioactivity as well as corrosion resistance of the Mg alloy. Crystal structure was characterized by X-ray diffraction (XRD). Crystallinity of the coating was about 70% in which HA is dominant phase. The amounts of hydrogen gas released during magnesium corrosion tests in simulated body fluid (SBF) were measured to evaluate the corrosion resistance of the coated samples. This coating could decrease hydrogen evolution from 100 per cm2.mL to about 15 per cm2.mL after 29h of immersion time.
Improvement of Corrosion Resistance of Gray Cast Iron Components by Surfacing with Gas Metal Arc Welding
Authors: Oechsner M. , Andersohn G. , Ellermeier J. , Heider B. , Reisgen U. , Sharma R. , Wieland S. , Gonzalez E. 
Published: October 2022

Abstract
The degradation of pump components by corrosion and complex damage mechanisms, e.g. erosion and cavitation leads to high costs through replacement and maintenance of parts. To increase the lifetime of cost-efficient components with superior casting properties, gray cast iron parts are surfaced with duplex stainless steel using an inert shielding gas metal arc welding process. The dilution of the surfacing increases with both increasing heat input and increasing thermal conductivity of the shielding gas. The microstructure is highly affected by the cooling conditions that may enhance diffusion processes and eventually lead to precipitation of deleterious carbides. Higher heat input and prolonged cooling duration during surfacing lead to high dilution and a pronounced carbide network and thus, substantially reduced corrosion resistance in artificial seawater. The corrosion of the surfacings in the potentiodynamic polarization test is driven by selective corrosion of the phase boundary between carbides and chromium-depleted austenite. Passive behavior is observed for coatings with low dilution and higher cooling rates, which showed homogeneous chromium distribution and no interconnected carbide networks. In conclusion, the corrosion behavior of gray cast iron was improved by surfacing with duplex stainless steel.
Ultrafine Powder Feeding in Cold Spray and FAPS Applications
Authors: Desaulniers Sylvain , Bessette Eric , Breton Jessica 
Published: October 2022

Abstract
This research looks at the work of Polycontrols in the field of additive manufacturing. Several technological breakthroughs are presented. We mainly draw upon tests performed with the ultrafine powder feeder at the National Research Council of Canada, and data gathered from different systems operating worldwide in aerospace facilities. This paper outlines the very unique capabilities of the feeder in the field of cold spray and finely-dispersed-particle air plasma spray (FAPS).
Comparison of TiO2 Targets Manufactured by APS and Sintering Processes for PAPVD Coatings Suitable in Technological and Medical Applications
Authors: Jaramillo Raquejo D. , Palacio C. C. , Ageorges H. 
Published: October 2022

Abstract
In surface science of functional oxides, Titanium dioxide (TiO2) is one of the most investigated crystalline systems either in rutile or anatase phases. Rutile phase is widely used in microelectronic, tribological applications and in the conversion of solar energy. Anatase phase is used in self-cleaning, antifogging, photo-catalytic and biomedical technologies. This work focuses on studying the required process conditions to obtain TiO2 targets by APS onto metallic substrates using commercial TiO2 powders (Oerlikon Metco in Switzerland) with suitable physical and chemical properties for technological and medical applications as PAPVD coatings. APS targets were compared to sintered ones. The raw powders were characterized by laser diffraction, SEM, XRF and XRD while the characteristics of the APS-deposited targets as well as the sintered ones were determined by SEM and XRD to identify the constituent phases. This work allowed confirming the advantages and limitations of both processes in terms of grain size, chemical composition, microstructural homogeneity and density in order to choose the best option to manufacture targets for PAPVD coatings for technological and medical applications.
Microstructural Analysis of Aluminum Coatings Deposited by HVOF Process on Complex Surfaces
Authors: Vanat Karen Juliana , Paredes Ramón Sigifredo Cortés , Pukasiewicz Anderson Geraldo Marenda 
Published: October 2022

Abstract
Aluminum coatings applied by thermal spraying are widely used for protection against marine corrosion. The HVOF process produces aluminum coatings with high particle velocity, at a higher temperature for longer, permitting a high adhesion among the deposited particles. The objective of this work was to analyze how the microstructure of the aluminum coating sprayed by HVOF was formed on different complex surfaces. The influence of different deposition process parameters on the coating, varying the angle of incidence during deposition, substrate preheating and nitrogen flow was studied. Outer corner and convex surfaces presented greater uniformity in the formed microstructures. The angle of incidence was the most influential parameter on the coatings, filling complex profiles better, with 60° of incidence, although the 90° of incidence increased the adhesion. The potentiodynamic polarization test was performed to evaluate the corrosion resistance of coatings. The higher preheating and lower angle of incidence increased the corrosion resistance of coatings. Corrosion tests in salt spray are in progress in order to compare with continuous results.
Macroline – New Solutions to Improve Abrasive Wear Resistance
Authors: Lanz Oliver , Scrivani Andrea 
Published: October 2022

Abstract
Highly wear resistant overlays for abrasive environments can be provided by welding technologies such as Plasma Transferred Arc Welding (PTAW) or Laser Cladding. Therefore, these overlays can contain higher amounts of hard particles with a desired homogeneous distribution through the weld overlay, all embedded in a metal matrix. Depending on the welding technology, the dissolution of the hard particles has to be considered as result of heat input and chemical reaction between hard particles and metal matrix while welding. Cast Tungsten Carbides (CTC) in self-fluxing Ni based alloys are widely used and accepted compositions and allow to target requirements such as hardness, impact toughness and/or corrosion resistance if required. This investigation compares CTC with Macroline Tungsten Carbide regarding abrasive wear resistance in Ni, Co and Fe based alloys applied by PTAW and Laser cladding and gives an outlook on potential new solutions for wear resistance in abrasive conditions. Beside the relative wear resistance, this investigation also focusses on the seam thickness as reaction zone between the carbide particles and the metal matrices. A first SEM and EDX analysis of a worn surface and precipitated phases provides an explanation regarding wear behavior in abrasive conditions.