With the new development of the LPPS Thin-Film technology (LPPS-TF), which is a special modification of conventional LPPS using reduced chamber pressures below 10 mbar, a new window has been opened to deposit uniform and dense thin layers onto large areas in short coating times. This spray process will allow the access to new market areas and will be able to bridge the gap between conventional thin film (< 1 - 10 µm) deposition using PVD/CVD processes and thick (> 50 - 200 µm) thermally sprayed layers. This paper presents the status of the LPPS-Thin Film technology as a hybrid coating process between thermal spray and vapor deposition and gives an overview of potential applications for functional thin coatings and large area coverage.

The objective of the present work is to produce Mg-PSZ (magnesia partially stabilized zirconia) powders that were used to coat oxygen sensor tubes by plasma spraying. It is well known fact that zirconia based oxide thin films are the most widely used material as ionic conductors of oxygen. In this study, MgO stabilized ZrO 2 powders were produced by the sintering and crushing method. Starting powders were a high grade ZrO 2 , and a natural hydromagnesite (Mg-HC) as MgO source. ZrO 2 , and MgO were mixed in the compositions of ZrO 2 - 9mol % MgO. The mixtures were ball milled by using ZrO 2 balls. The fine powders were stabilized via thermal treatment in air at 1540°C for 24 hours. The powders were calibrated to the correct particle size distribution for plasma spraying. All powder samples were characterised by a well-defined techniques with an exhibited an average particle size of 10 µm. The powders consisted of monoclinic, tetragonal and cubic phases. They were sprayed by plasma spray to produce high temperature Mg-PSZ coatings on oxygen sensor tubes. It is worthwhile to point out that high temperatures were generated in the plasma spray jet, and the rapid quenching of the molten Mg-PSZ droplets deposited on the cold substrate subsequently occurred. After this process, thermal treatments were carried out to improve the film density and microstructural stability.

In Municipal Waste Incinerators (MWI) considerable corrosion problems of critical components, such as superheater or boiler tubes, are always reported. Especially in modern WTE plants the need of efficiency increase requires operation at higher temperatures, which in turn enhances the corrosion rates. Laser cladding technology was successfully used for the production of anticorrosion and resistant-to-erosion coatings on tubes of superheaters and boilers. Compared to protective coatings produced by flame spraying devices, laser cladding is virtually porosity free and metallurgically bonded to the substrate, ensuring the possibility of bending the clad tubes without any damage such as cracks or spalling. This ability to sustain high deformation rate is absolutely necessary for the construction of superheaters serpentines, opening the door to the production of a whole superheaters assembly protected by a laser cladding. Due to the very low thermal load of the process, if compared to usual GMAW welding, laser cladding allows producing coatings with very low iron content (1-3%) even in a single pass with thickness lying in the range 0.7 -1.0 mm. Therefore laser technology enables to produce high quality coatings with a considerable saving in feeding materials, when compared to conventional GMAW welding where 2.5 - 3 mm thick cladding is necessary to have the same iron content of a single pass laser cladding. In this paper are presented advantages of this new technology and CESI RICERCA facilities for industrial production of MWI superheater and boiler clad tubes by its new automatic diode laser workstation. Results of a campaign of in-plant tests and performances obtained in operation by several laser clad components installed in European MWI plants are also presented.

Globalisation is moving business’s emphasis away from basic technologies towards “information and knowledge”. Indeed, knowledge based processes and products have become a new paradigm. As such, the management (control and retrieval) and use of data has become a central activity both for companies themselves and, increasingly, within wider supply chains. Adding “value” to data and creating “knowledge” will be a key element of future business growth. Handling and, more importantly, exploiting the current explosion of electronic information represents a real challenge to companies. However, the emergence of new, semantic tools which can “intelligently” interrogate and manipulate data could turn a potential problem into an opportunity.

This study aims at investigating the antiviral properties of HAp/Titania composite coating. TiO 2 has promising photocatalytic activity and good efficiency in destroying the bacteria, and various viral species. SPPS is an emerging technology which can use solution to synthesis oxides. This study is focused to understand the basic mechanism of titanium complex and coating formation method in order to produce oxygen deficient type visible light sensitive coating. Coating surface was studied using XPS, UPS and REELS to understand the electronic structure and optical properties. XPS result indicated the crystallinity of HAp coating has increased as compared to conventional plasma sprayed coating and Ti 3+ species & oxygen vacancy was formed on the surface of the titania coating which can act as a charge trap. Band gap, ionization energy and electron affinity of the coating were also evaluated to further support the photocatalytic performance of this coating. There was increment in optical absorption area on the coating surface from rutile & anatase form of TiO 2 . Antiviral test will be carried out to reveal its virucidal effectiveness.

Aerosol cold spraying (ACS) is modification of low-pressure cold spray technology which allows to deposit ceramic and metal-based coatings. ACS technology in vacuum possesses the formation of films from sub-micro and nanoparticles directly at room temperature. The ACS technology is still under development to cover more application and discover solutions of spraying different kind of powders on different types of material substrate and optimizing spraying conditions to obtain the best results. The main objective of the present work is to develop a new ACS cold spray technology of Hydroxyapatite (HA) and Copper powder deposition onto both the implants and ceramic substrates. The new AD spraying system with radial injection of particles to be deposited is constructed and tried. An influence of technology parameters on the coating structure and properties are presented. In addition, the combined cold spray and sintering technology technique is further investigated for additive manufacturing applications.

The thermal spray industry requires universal and economical HVOF systems for the production of high-quality coatings with high deposition efficiencies. In the last years classic HVOF guns have been adapted insufficiently to these requirements. This paper shows how modern numeric simulation and new inventions in gas safety engineering enable the development of a spray system for powder and wire feedstock that is optimized especially for the needs of the market. The new IBEDA TopGunAirJet is equipped with an air-cooled ‘de Laval’-like nozzle. The optimized expansion of the gas leads to high gas and particle velocities as well as to moderate flame and particle temperatures. Advantages of the TopGunAirJet are the achievable high coating quality, the low energy consumption (propane, ethene), the utilization of powder or wire and the efficient air cooling of the thermally loaded nozzle parts. Additionally, as a result of the axial powder injection, the free jet divergence and the nozzle wear are minimized. By varying the powder gas flow, the dwell time of the particles inside the flame can be influenced in order to avoid fusing of hard phases. As an example, WC-Co 88-12 coatings are presented and compared to coatings sprayed with a standard HVOF system of the 3rd generation. Different 316L coatings are produced and tested in comparison to standard HVCW coatings to show the workability of solid and cored wires. Finally, extensive LDA measurements are used for in-flight particle analysis, and investigations concerning the achievable deposition efficiencies are carried out.

The introduction of new wire arc spraying equipment with chopped power supplies offers many possibilities to improve the wire arc spraying process. These power sources provide higher process stability even at reduced voltages. On the one hand conventional applications can be enhanced and on the other hand new processes can be developed. Due to the high process stability the introduction of additional particles into the atomizing gas stream is possible. This can be applied to produce coatings with a high wear resistance as well as a high surface roughness. A combined technology of particle injection and the productive wire arc spraying process enables the economic production of innovative functional surfaces. In the last years ITSC, the injection of corundum particles had been presented. In this paper further strategies for inserting particles into the gas stream and experimental results are shown for iron based coatings. For the reinforcement different carbides were injected into the atomizing gas stream.

Abradable seals have been used in jet engines since the late 1960's. Today they are seeing applications in low pressure and high pressure sections of compressors as well as the high pressure turbine module of jet engines. Clearance control systems using abradable coatings are also gaining ever more attention in industrial and steam turbine applications. Thermal spraying is a relatively simple and cost effective means to apply abradable seals. Abradable coatings work by minimizing gaps between rotating and stationary components by allowing the rotating parts to cut into the stationary ones. Typically plasma and combustion spray processes are used for applying abradable coatings. The types of coatings employed in the HP turbine are zirconia based abradable material systems with polymer and, in some cases, solid lubricant additions such as hexagonal boron nitride. The coatings are designed to work at service temperatures of up to 1200°C. Types of matrix materials used in the low and high pressure sections of the compressor are aluminum-silicon, nickel and MCrAlY based systems. These compressor type systems typically also contain fugitive phases of polymer and/or solid lubricants such as hexagonal boron nitride or graphite. Operating temperature, depending on the material of choice, can be up to 750°C. Regardless of the specific application, fugitive phases and porosity are needed for abradable coatings. Polymers are used to create and control porosity in plasma sprayed coatings, a critical design requirement in adjusting abradability and erosion properties of thermal spray coatings. Combustion spray coatings generate porosity through the lower deposition velocities and temperatures compared to plasma and typically do not need polymer phases. Solid lubricants are added to help weaken the structure of thermal spray coatings and reduce frictional heating and material transfer to the blade.

Manufacturing of diamond abrasive wheel has been achieved through kinetic spraying in order to simplify the manufacturing process and improve the mechanical properties. However, size of the initial feedstock diamond particles is reduced by fracturing during the process. Uniform distribution of diamond particles in the coating layer is significantly important for obtaining grinding properties of diamond abrasive wheel. In this study, optimized nickel thin film which is coated around the surface of diamond particle was used to prevent the fracture of diamond particles during spraying and improve the properties. Thickness of the nickel thin film was optimized by ABAQUS 6.7-2 finite element analysis software as 3 µm for 20 µm diamond and bronze particles. Fraction and size distribution of the diamond particles present in the coating were analyzed through Scanning Electron Microscope (SEM) and Image analyzer methods.

For the manufacturing of metal matrix composites, a combined process of thermal spraying followed by forging in the semi-solid state can be applied. In previous work, it has been shown that thermal spraying leads to a globular microstructure that is suitable for semi-solid forming. Thereby, penetration of the spray material into the reinforcement phase leads to reduced matrix flow paths and thus reduced forming time and fiber disarrangement during the forming process. The main requirement is a low substrate and coating temperature during matrix deposition. By control of the process temperature, geometrical accuracy of the prepreg material and it’s handling between each process step can be significantly improved, leading to an economical method that is a superior alternative to the well established MMC processes like diffusion bonding or squeeze casting. Moreover, due to low process temperatures and process time during matrix application, chemical attack of carbon fiber reinforcements can be reduced. Process development for the manufacturing of continuous fiber reinforced prepregs was focused on the analysis and control of particle properties and substrate temperature. In order to improve the temperature control during arc wire spraying, numerical process analysis of the cooling system was applied. Particle in-flight analysis with the SprayWatch system was used to obtain direct spray parameters as input data for the numerical models. The simulation results were verified by experimental infrared thermography of the substrate during coating. By the use of an optimized cooling system, dense coatings without cracks were achieved with different coating thickness, thereby tailoring the fiber volume content of the final MMC component.

The heating of the substrate by the jet may influence on the process of coating deposition by DYMET technology. It can be observed as deposition efficiency variation at various nozzle transverse speeds. Experimental investigation of the deposition efficiency variation for different jet stagnation temperatures and different substrate thermal properties is presented and discussed. The suppression of substrate influence on the deposition process with the coating thickness growth is demonstrated.

In this work, completely ceramic heating elements have been developed by the combination of conductive and insulating thermally sprayed oxide coatings. These heating elements with a total thickness of less than 1 mm have been directly applied on metallic substrates. APS- and HVOF-sprayed Al 2 O 3 and spinel (MgAl 2 O 4 ) coatings were employed for insulation. A comparative analysis of the insulating properties (dielectric strength, electrical resistivity) of these coatings is presented. The HVOF-sprayed spinel coatings show better dielectric breakdown strength and higher electrical resistance stability. TiO x , TiO 2 -10%Cr 2 O 3 and TiO 2 -20%Cr 2 O 3 powders have been used to prepare the electrical conductive coatings. The thermal and oxidation stabilities at high temperature, as well the electrical properties have been investigated. Addition of Cr 2 O 3 reduced the oxidation rate of titanium oxide and increased the operational temperature of the heating coating. A ceramic heater consisting of spinel coating as insulator and TiO 2 - 20Cr 2 O 3 as conductor was sprayed on a metallic roller and the electrical stability during the long-term (300h) thermo-cycling (from RT to 300°C) was successfully tested.

This paper describes computational fluid dynamics (CFD) simulations for state-of-the-art flame-spray processes and experimental validation of these simulations. Alternative nozzle designs are presented along with analysis of their impact on flow-field and flame parameters. Validated CFD models are used for performance prediction of these nozzles. Several variants are compared and the possibility of improvement of technology parameters is analyzed.

This work shows that hydroxyapatite (HA) can be cold sprayed simultaneously with titanium to form thick biocompatible coatings without compromising the phase constituents of the bioceramic material. XRD analysis indicates that the phase composition of the HA in the deposit is identical to that of the powder. The work also shows that very dense Ti and Ti-HA composite coatings can be produced using sponge Ti powders and nitrogen process gas. The adhesion strength of the cold-sprayed Ti-HA exceeded the reported values of comparable plasma-sprayed coatings.

This paper provides an overview of thermal spray activities in Finland, Sweden, Norway, and Denmark. In Finland, thermal spray technology has widest use in pulp and paper processing, protecting various types of rolls and cylinders. In Sweden, the technology is of great importance in the manufacture of aero engines and industrial gas turbines. In Norway, thermal spraying is widely used in offshore applications, including subsea oil drilling enterprises, and in Denmark, thermal spraying is used in boilers, maritime diesel engines, and for wear resistance of machine tool components. Development and innovation in thermal spray technology in northern Europe is dominated by research conducted in Finland and Sweden, followed by Denmark and Norway.

Bead blasting and thermal spray coatings are often applied on process kits used in vacuum deposition chambers to improve adhesion between kit surfaces and deposited films. This study shows that in order to maximize chamber service time and reduce processing defects, thermal expansion mismatches must be considered between chamber components, sprayed coatings, and vacuum deposited films. When a titanium sheet coated with arc sprayed aluminum was placed in a titanium nitride deposition chamber, significant particle spiking was observed. However, during the same period of chamber service time, particle performance was stable for titanium coated with arc sprayed molybdenum. It should be noted that the thermal expansion coefficients of Ti and Mo are much closer than those of Ti and Al. By further optimizing the cohesion strength of the arc-sprayed Mo coating, even lower particle counts have been achieved, corresponding to fewer processing defects and prolonged chamber kit lifetime.

A chromium alloy as used for the metallic bipolar plate of a solid oxide fuel cell was processed by RF-plasma spraying to dense free-standing parts. The plasma spray parameters were successfully adapted for two different types of powder. The layer properties, particularly the porosity and the splat shape were investigated in dependence on the spray angles. All the coatings produced with off-normal spray angles show higher porosity increasing from spray angles of 60° to 30°. The splat orientation changes from parallel to the inclined surfaces to almost perpendicular to the plasma jet axis with shallower angles.

This study focuses on RF-Plasma Technology (RFPT) to enhance the physical properties of powdered materials (metals, carbides, ceramics, inter-metallics, and mixtures). The efficiency and flexibility of RFPT allows for the economically viable production of powders with a high degree of densification, spheroidization and purity. RFPT is based on the used of RF inductive power used to create a plasma at atmospheric pressure. A complex model based on theoretical calculations and empirical data has been developed to describe changes in particles exposed to the plasma stream for a variety of process parameters. A specific combination of parameters is referred to as a scheme. Advanced schemes have been developed to increase the coefficient of heat transfer from the plasma stream to particles by up to 35%. RFPT is especially useful for the production of powders that have been difficult or impossible to create with traditional methods. Some of the materials processed include: ZrO 2 , W 2 C, WC and WC-Co combinations. Particle size distribution (PSD) can be tightly controlled, and can vary from 5 to 600 microns.

A comprehensive approach is presented for facilitating the implementation of advanced plasma spray processing technology in the manufacture, repair, and refurbishment of industrial components. This approach employs an integrated methodology for combining several advanced computer-based methods, including: 1) an interactive multimedia-based education and training tool to effectively store and retrieve plasma spray processing information in a variety of formats; 2) an expert system to select plasma spray feedstock material for a specific coating function; 3) a one-dimensional plasma spray process model that allows simulation of plasma spray processing conditions for identifying operational envelopes for a selected feedstock material; 4) an interface fracture model for identifying appropriate acceptance criteria for reduced cracking along the coating/substrate interface; and 5) a set of computer-based nondestructive test methods for performing quality assurance and control. This comprehensive approach and the integrated methodology provide an advanced engineering tool for the selection, optimization and implementation of specific advances in plasma spray processing technologies. A major outcome is the reduced need for expensive and time-consuming trial-and-error methods in evaluating the application of plasma spray coatings for the manufacture, repair, and refurbishment of specific industrial components. This comprehensive approach and integrated methodology can be extended to include other thermal spray processing technologies as well.