bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Nanostructured Lanthanum Zirconate Coating and Its Thermal Stability Properties
Authors: Zhao X. , Zeng K. , Xie J. , Ren X. , Yu Y. 
Published: September 2022

Abstract
In this paper, nanostructure Lanthanum zirconate thermal barrier coatings (MCrAlY+ La2Zr2O7) were prepared by atmospheric plasma sprayed (APS). The microstructures and thermal stability properties were systematically studied by Scanning Electric Microscopy (SEM), transmission electron microscope (TEM) and X-Ray diffraction(XRD). The results showed that the nanostructured lanthanum zirconate coatings were typical lamellar structure which was composed of columnar grains about 90nm in diameter. A large quantity of micro-cracks and homogeneous distributed fine pores formed in the nanostructured zirconia coating. After ablation at 1300 °C for 24 h, no apparent phase transformation was observed in lanthanum zirconate coating. The growth mechanism of the grains was subsequently discussed.
High-Temperature-Functionalization of Surfaces: Drag Reduction and Self-Cleaning
Authors: Wilden J. , Jahn S. , Drescher V.E. , Schaaf P. 
Published: September 2022

Abstract
Increasing requirements on technical components for high-temperature-applications (e.g., turbine blades) demand for new developments in surface engineering. The selective combination of materials with positive and negative thermal expansion coefficients (NTE) will lead to a reversible activation of the surface depending on surface temperature: The generation of a riblet structure (“shark skin”) in operation condition by thermal expansion of the matrix and shrinkage of the NTE-ceramic and self-cleaning of the surface at cool down as a result of the reversal of the process. Due to its hygroscopicity the chosen NTE-ceramic Y2W3O12 needs to be embedded into a binder matrix. Therefore a feedstock powder consisting of MCrAlY, WO3 and Y2O3 is mechanically alloyed in a high-energy ball mill. The powder is deposited on substrates by thermal spraying (VPS and HVOF) and laser cladding as well. After coating process a lateral- and depth-selective ion implantation of tungsten, yttrium and oxygen will force nucleation in predefined areas. A following heat treatment of the specimens supports the in-situ-formation of Y2W3O12.
Influence of Air Pressure and Plasma Remelting in the Microstructure and Cavitation Resistance of the Arc Thermally Sprayed Cobalt Stainless Steel
Authors: Pukasiewicz A. , Capra A. , Paredes R. 
Published: September 2022

Abstract
Many studies have investigated methods to reduce cavitation damage in hydraulic turbines and reduce residual stresses after coating deposition. In this work, a cobalt stainless steel was applied by arc thermal spraying. The influence of air pressure deposition and plasma remelting on the microstructure, oxide volume fraction, porosity, microhardness, and cavitation resistance were studied. Microstructures and properties of the AS895HY cobalt stainless steel coatings were investigated by x-ray diffraction, optical microscopy, scanning electron microscopy, microhardness testing, and ultrasonic cavitation testing (ASTM G32-93). The increase in air pressure, 280 to 550 kPa, modified the oxide fraction from 10.9±1.8% to 24.1±2.8% in the samples. The mass loss results in the cavitation tests were 13.8, 19.2, and 15.0 mg/h for the samples with 280, 410, and 550 kPa, respectively. The remelting of the sprayed coatings eliminated the oxides and porosity. Austenite formation was observed in the two remelted layers with decreases in microhardness; for the first layer, this occurred because of the AWS309L substrate dilution. The PTA remelting reduces the mass loss rate to 0.497 mg/h, with 8.02 hours incubation period. Phase transformations were observed in the remelted coating, but not verified in the arc thermal sprayed coatings.
Industrial Technology of Laser Assisted Direct Metal Deposition
Authors: Thivillon L. , Pervushin D. , Bertrand P. , Smurov I. 
Published: September 2022

Abstract
Laser assisted direct metal deposition (or simply DMD) belongs to the family of laser cladding. This is flexible and efficient method for elaboration of diverse coatings including functionally graded, multi-layered, etc. The coatings are characterized by excellent adhesion (metallurgical contact), low porosity and variable thickness up to several millimeters and even centimeters. Actually DMD technology is under intensive development. The most important objective is to increase product quality, process stability and reproducibility along with the simultaneous decrease of risks, failures and defects both on processes and on end-products. The use of the TRUMPF 505 DMD machine with 5 kW CO2 laser allowed to scale-up the technology to an industrial level. The targeted applications are related to petrol, chemical and plastics industries where wear resistance is improved by deposition of a hard-phase coating; in aeronautics DMD is used for near net shape manufacturing from Inconel alloys.
Sealing up the Holes by Gas Dynamic Spraying
Authors: Buzdygar T. , Kashirin A. , Klyuev O. , Shkodkin A. 
Published: September 2022

Abstract
High density and low porosity of gas dynamic sprayed coatings may provide gases and liquids impermeability. But jet deflection and stagnation in the narrow splits and reach-through holes prevent from sealing up the deep substrate defects by gas dynamic spray. The correct choice of powder blend makes the gas dynamic spray process applicable to the splits and holes sealing up. The approaches to the defects sealing up by gas dynamic spray and some applications are presented and discussed.
Characteristics and Heat Treatment of Cold-Sprayed Al-Sn Binary Alloy Coatings
Authors: Kim H.J. , Ning X.J. , Jung D.J. , Lee C. 
Published: September 2022

Abstract
In this study, Al-Sn binary alloy coatings were prepared with Al-5wt.%Sn (Al-5Sn) and Al-10wt.%Sn (Al-10Sn) gas atomized powders by low pressure and high pressure cold spray process. The microstructure and microhardness of the coatings were characterized. The as-sprayed coating were heat treated at 150, 200, 250 and 300 °C for 1 hour, respectively. The effect of heat treatment on microstructure, microhardness and content of Sn phase of the coatings were investigated. The bonding strength of as-sprayed and heat treated Al-Sn coatings were also studied. The results show that the dense and well-bonded Al-10Sn coating can be deposited by low pressure with helium gas while Al-5Sn coating by high pressure cold spray with nitrogen gas. The content of Sn for both Al-5Sn and Al- 10Sn in as-sprayed coatings are consistent with that in feed stock powders. The coarsening and/or migration of Sn phase in both coatings were observed when the annealing temperature exceeds 200 °C. Furthermore, the microhardness of the coatings decreased significantly under the annealing temperature of 250 °C. EDAX analysis shows that the heat treatment has no significant effect on content of Sn phase in Al-5Sn coatings. Bonding strength of as-sprayed Al-10Sn coating is slightly higher than that of Al-5Sn coating. Annealing under 200 °C can increase the bonding strength of Al-5Sn coatings.
Mechanical Properties of WC/Co Coatings Prepared by Cold Spraying
Authors: Kitamura J. , Sato K. , Aoki I. , Sakaki K. , Takahata M. , Shimizu Y. 
Published: September 2022

Abstract
Wear properties of WC/Co cermet coatings have been investigated prepared by cold spraying. Influence of cobalt contents (12~25wt.%), WC particle size (0.2 and 1.8 µm) and agglomerated-and-sintered powder size (-20+0 and - 45+15 µm) on abrasive wear resistance, micro hardness and coating structure is studied, in detail. It has been found that both smaller WC particle and decrease of cobalt content are effective to produce dense, hard and highly wear resistant coating. Smaller powder size is also favorable to make a coating with high mechanical properties. As a result, the cold sprayed coating from WC(0.2 µm)/12wt.%Co with powder size of -20+0 µm has best mechanical properties within this study. This coating has high uniformity and high density with little pores compared to conventional HVOF sprayed coatings. Abrasive wear resistance of the cold sprayed coating, investigated using Suga-abrasion tester, has been almost comparable to HVOF sprayed coating prepared from same feedstock. Strong correlation is also seen between Vickers hardness and abrasive wear resistance. Microstructural analysis suggests that further improvement of coating uniformity by decrease of small pores with the size of sub micron and homogeneous dispersion of WC grains in the cobalt matrix is required to improve the mechanical properties.
Influence of Interface Temperature and Strain Gradients on Impact Energy Model of Soft Particle on Hard Substrate in Kinetic Spraying
Authors: Ji Y. , Yoon S. , Bae G. , Kumar S. , Lee C. , Choi H. 
Published: September 2022

Abstract
In this study, individual particle impact behaviors of soft particle on hard substrate were observed. The ratio of bonds was compared to the difference between adhesion and rebound energies. To improve the existing model, the equation for effective yield strength was modified and finite element analysis was applied to estimate the temperature and strain gradients. The energy difference was derived from the strain and temperature of the elements and compared to the experimental ratio of bonds.
Microstructure Observation on the Interface between Warm Spray Deposited Titanium Powder and Steel Substrate
Authors: Kim K.H. , Watanabe M. , Mitsuishi K. , Kawakita J. , Wu T. , Kuroda S. 
Published: September 2022

Abstract
Titanium particles were deposited on a steel substrate by the impact of high velocity in warm spraying. In the process, nitrogen gas at various flow rates was mixed to control the temperature of a supersonic gas flow generated by combustion. TEM and other techniques were used to analyze the microstructure of the interface between the titanium coatings and the substrate. At the lower nitrogen flow rate, thick oxide double layers in the interface region were observed. The adhesive strength of the coating was high even at lower particles’ velocity possibly because the mechanical interlocking between the titanium particle and the substrate could be enhanced by the high deformability of heated particles. As the nitrogen flow rate increased, however, just a little oxide and a very thin oxide layer covering on the titanium splats were locally detected. The highly localized pressure and the resultant intensive shear stress generated within a titanium particle by the impact could reveal the fresh metal surface through break-up of the thin oxide films on the particle and the substrate. As a result, the metallic bonding between the deposited particle and the substrate was formed and increased the adhesive strength remarkably beyond a certain impact velocity.
Characterization of Low Pressure Type Cold Sprayed Aluminium Coatings
Authors: Ogawa K. , Ito K. , Ichimura K. , Ichikawa Y. , Shoji T. 
Published: September 2022

Abstract
Aluminium alloys are widely used for transportation facilities, because of light weight and high corrosion-resistance. If there are some cracks in transportation, sometimes they repair by welding. However, it is difficult to weld aluminium materials. Because, Aluminium has high specific thermal conductivity and high coefficient of thermal expansion compared with that of steel. The cold spray technique is known as a new technique not only for coating but also for thick depositions. It has many advantages, i.e. dense coating, high deposition rate and low oxidation. Therefore, it has a possibility to apply the cold spray technique instead of welding to repair the cracks. What seems to be lacking, however, is deposition mechanisms and mechanical properties of deposition produced by low pressure type cold spraying. This is a very important issue for applying the cold spray to repair some structures. In this study, elucidation of deposition mechanisms and evaluation of mechanical properties for the low pressure type cold sprayed aluminium depositions were investigated. As a result of elucidation of deposition mechanisms, it can be clear that the particle deposition needs to activate the surface by several impingements. Furthermore, as a result of evaluation of mechanical properties, the cold sprayed specimen showed higher strength than the monolithic specimen in the case of compressive loading to the coating.
PSI: An Innovative Method to Determine and to Classify Particles during the Thermal Spray Process
Authors: Zimmermann S. , Landes K. , Schein J. 
Published: September 2022

Abstract
Coatings produced by thermal spray processes are determined by particle parameters, which can be investigated using various diagnostic systems. With the newly developed PSI (Particle Shape Imaging) four (velocity, size, shape and position) important particle parameters can be measured and evaluated. The data acquisition system consists of two separate optical setups, thus a single particle produces two pictures in the lower and upper area of an ICCD-Camera. These pictures are evaluated by assigning specially developed shape and size parameters to the particles, which in combination with the velocity can be used to predict the coating quality. This instrument can be used to determine the optimum spray parameters (i.e. find the optimal distance between substrate and thermal spray system) and to survey the coating process. A newly developed, mobile PSI-System will allow operation at industrial and research thermal spray facilities.
The Application of Cr3C2-NiCr Coatings to Improve the Corrosion and Wear Properties of an AA7050 Alloy
Authors: Magnani M. , Suegama P.H. , Benedetti A.V. , Espallargas N. , Dosta S. , Guilemany J.M. 
Published: September 2022

Abstract
The Cr3C2-NiCr coatings were sprayed on an AA 7050-T7 alloy by HVOF Thermal Spray Process using AMPERIT 586.054 powder. The substrate was refrigerated during the sample preparation using liquid nitrogen in a device specially designed for this purpose. The spray conditions were also performed increasing the carrier gas flow or the oxygen flow. The XRD and SEM studies showed well-bounded coating/substrate interface, pores, metallic matrix, chromium oxides, carbides, and carbides dissolution into the matrix. The structure comparison between the samples showed a denser structure due to the increase in the carrier gas velocity and the highest carbide dissolution due to the high temperature achieved during the spray process. All samples showed similar wear abrasive behavior, and all of them showed wear rates 7 times higher than the aluminum alloy. All samples also showed corrosion resistance much higher than the AA7050 alloy in NaCl solution.
Microstructure and Wear Resistance of Plasma-Sprayed Carbides and Ceramic Coatings Deposited on an Invar Alloy Surface
Authors: Turbil M. , Rosso M. , Giolli C. , Rizzi G. , Scrivani A. 
Published: September 2022

Abstract
Invar alloy (Fe – 36%Ni) is used in industrial applications which require high dimensional stability because of its exceptionally low thermal expansion coefficient. Purpose of this work is to enhance the performance of molds for the production of carbon fiber reinforced plastic (CFRP) components. Four different kinds of commercial powders were coated on an Invar substrate: Al2O3 - 12TiO2, Cr2O3 and ZrO2 - 8Y2O3 by Air Plasma Spray (APS) and WC - CoCr by High Velocity Oxygen Fuel (HVOF). Metallographic microscopy observation and SEM analysis were carried out and microhardness and fracture toughness were evaluated by means of the micro - indentation method. Friction behaviour and wear resistance were evaluated in dry sliding conditions with Pin On Disk apparatus for not coated Invar substrate and for the different coated substrates. Chromium oxide and tungsten carbide coatings exhibited higher mechanical characteristics respect to the other coatings: chromium oxide had the higher hardness value and tungsten carbide the higher fracture toughness. Tungsten carbide coating had the lower average coefficient of friction and together the chromium oxide the lower wear mass loss and wear rate. Among APS ceramic coatings, Cr2O3 exhibited the best mechanical and tribological behavior while the HVOF cermet coating exhibited the best behavior among all the coatings.
The Jet Characteristics of Supersonic Plasma Jet Spraying System
Authors: Yang H. , Wang L. 
Published: September 2022

Abstract
The jet characteristics of supersonic plasma jet spraying (SPJS) system were studied. Comparison of jet property was made between conventional plasma spray system and SPJS system. The results showed that the characteristics of the SPJS system are superior to the latter system. The particles velocities in the range of 400~800 m/s are obtained for supersonic plasma jet guns with 4.5 mm diameter nozzles and 60 l /min total gas flow rates, SPJS operate about 36 KW. The particle velocity is more than two times as much as conventional plasma jet spraying. The supersonic plasma jet is much longer than that of the conventional torch. It can bring about improvement for flying powder heated and accelerated and also prolong spray distance.
Influence of Microstructure on Ionic Conductivity of Plasma-Sprayed Yttria-Stabilized Zirconia Coatings
Authors: Xing Y.-Z. , Li C.-J. , Li C.-X. , Wu H.-L. , Li R.-T. , Zhang Q. 
Published: September 2022

Abstract
During plasma spraying, high substrate temperature contributes to increase the interface temperature between flattening droplet and substrate and subsequently promotes the through-lamella grain growth in the coating. In this study, yttria stabilized zirconia (YSZ) coatings are prepared by atmospheric plasma spray (APS) on the stainless steel substrate preheated to different temperatures from room temperature to 1100°C. The microstructure of the coatings is characterized from polished and fractured cross sections by SEM. The ionic conductivities of the coatings are measured using both DC and AC methods, and the relationship between ionic conductivity and microstructure of coatings is examined. SEM observation shows that the coatings exhibit different microstructures with different substrate temperatures. With the increase of substrate temperature, the columnar grain growth continuously across lamellar interfaces is enhanced and subsequently the intersplat bonding ratio in the coating is increased. The ionic conductivity of YSZ coatings at the direction perpendicular to coating surface is significantly increased through the microstructure development by increasing deposition temperature.
Thermal Cyclic Behavior of Plasma-Sprayed YSZ/AI2O3 Thermal Barrier Coatings
Authors: Saral U. , Ustel F. , Toplan N. 
Published: September 2022

Abstract
Thermal barrier coatings (TBCs) were deposited by an Air Plasma Spraying (APS) technique. The coating comprised of YSZ – 0, 20, 50 and 80 wt % Al2O3; NiCrAlY bond coat; and AISI 304L stainless steels substrate. Thermal shock tests were performed over the specimens, at 1000 °C and 1200 °C for 5 min and then forced air quenching. The samples were directly pushed into a tube furnace at 1000 °C and 1200 °C. The results were prominent in forced air quenching tests at 1000 °C , where the lives of the TBCs were observed more than 66 cycles. It was noticed that with increase of Al2O3 content the thermal shock life of the specimens decreased. Further, the coating roughness decreased by Al2O3 addition. It was observed that with decrease in coating roughness, the thermal shock life decreased slightly.
Mechanisms of Residual Stress Generation in Plasma-Sprayed Hydroxyapatite Coatings
Authors: Yang Y.C. 
Published: September 2022

Abstract
From the past studies of the residual stress occurred during the plasma spraying, the different results were obtained; the arguments of these previous works were not only in the value of residual stress but the stress state existed in the HACs. The residual stress generation theory stated in these literatures appear to be oversimplified, hence a more basic study is needed to explore the contention on the residual stress state in HA coating during plasma spraying. In this study, in order to obtain the whole and accurate residual stress value and state, the residual stress was measured by using the material removal method. For the purpose of inferring the generation mechanism of residual stress, the particular forms of the substrate holder and various cooling system were employed. The results show that the difference between the HAC and substrate temperature is the main factor that dominates the residual stress state. HAC/Ti-substrate on the hollow rotational holder with the back cooling system would lead to the higher temperature in coating than substrate during plasma spraying and result in the tensile residual stress in the HAC. On the contrary, HAC with the front cooling system displayed much lower temperature than the Ti-substrate that fixed on non-hollow holder and hence the compressive residual stress occurred. These could be attributed to the differences of volume shrinkage between the HAC and Ti-substrate that from different initial temperature to room temperature. In another word, the residual stress state is depended on the spraying program not always tensile or compressive state.
New Developments in the PROTAL Process for the Coating of Cylinder Bores
Authors: Costil S. , Liao H. , Danlos Y. , Coddet C. 
Published: September 2022

Abstract
To avoid the constraints due to the conventional surface preparation before thermal spraying (degreasing and sand-blasting), the PROTAL process was developed implementing a Q-Switched Nd:YAG laser with a very short pulse duration to prepare the surface simultaneously to the coating buildup. Until now interesting results were obtained both from the adhesion and economical points of view. Specific parameters were developed according to the spraying process (APS, HVOF, wire arc), the powder (Cu alloy, Al2O3, WC-Co, ...) as well as the part nature (Ni alloy, Magnesium, steel, aluminium alloys, etc.). Considering the wide development of thermal spray applications in the automotive industry, new developments of the PROTAL process were considered in order to reach the feasibility of an internal laser treatment of the parts. After a presentation of the implementation of a new laser head in the thermal spray environment, some results concerning the case of a metallic coating (ferrous alloy) on a metallic part (aluminium alloy) will be presented.
New Industrial Applications for Cold Spraying
Authors: Hartmann S. 
Published: September 2022

Abstract
Since the first installation of a cold spray system at OBZ Innovation GMBH in 2002 the application areas of cold spraying have increased greatly. Cold spraying has developed into a safe and reliable process that is used successfully in various areas of industry. In this presentation current applications and new project developments at OBZ Innovation GMBH are demonstrated. Furthermore within an outlook the new possibilities with the latest cold spray technology, the KINETICS-8000-HP, are demonstrated. With this unit it is possible to increase the deposition rate compared to previous cold spray systems and expand the material spectrum usable for cold spraying to include higher refraction materials – all while cutting costs, increasing quality and maintaining excellent process reliability.