The Interaction between Particles and a Plasma Beam in the Thermal Projection Process

2009 ◽  
Vol 83-86 ◽  
pp. 801-809
Author(s):  
Ilhem Kriba ◽  
A. Djebaili
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Particle Interaction ◽  
Extreme Temperature ◽  
Thermal Spraying ◽  
Spray Parameters ◽  
Spray Process ◽  
Wide Range ◽  
Coating Formation ◽  
Jet Characteristics

Plasma spray processes have been widely used to produce high performance coatings of a wide range of Materials (metallic, non-metallic, ceramics), offering protection from, eg. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. Good agreement of the virtual spraying process with the real coating formation is achieved by modelling the particular process steps. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma –particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model.

Porosity Control of Thermally Sprayed Ceramic Deposits

1998 ◽  
Author(s):  
P. Chraska ◽  
V. Brozek ◽  
B.J. Kolman ◽  
J. Ilavsky ◽  
K. Neufuss ◽  
...  
Keyword(s):  
Gas Permeability ◽  
Water Immersion ◽  
Thermal Spraying ◽  
Spray Parameters ◽  
Post Processing ◽  
Free Standing ◽  
Spray Process ◽  
Wide Range ◽  
Controlled Porosity ◽  
Selection Of

Abstract Porosity regulates the deposit's properties and therefore methods for its control are of a vital industrial importance. Thermal spraying can produce deposits in a wide range of porosities by selection of a spray process itself, by selection of spray parameters, feedstock size and chemistry, etc. Manufacturing of deposits with controlled porosity may be difficult if the selection of spray processes and materials is limited. Special methods of deposition or/and subsequent post processing may be therefore necessary. These methods are studied in the presented work. All spraying was done with the water-stabilized plasma (WSP®) system PAL 160. Thick deposits and free-standing parts were sprayed from alumina, zircon, metal Al and Ni powders and their combinations. Porosity was characterized by number of techniques such as gas permeability, water immersion, MIP, SEM and SANS. Mechanical properties were characterized by the Young's modulus. Special methods of deposition, such as spraying of mixtures of ceramics and metals were successfully used. Either sandwiched-structures with alternating layers of ceramics and metals were sprayed (for the sealing purpose) or mechanical mixtures of ceramic and metallic feedstock were sprayed. Several post-processing methods were used to change porosity volumes or other materials characteristics. To increase the porosity the metallic phases were subsequently removed by leaching or by annealing at temperatures above the melting point of metal. A number of sealing materials (organic and inorganic) were used to seal the pores by infiltration at ambient or higher pressures. The results show, that significant changes of porosity volume and, especially, of the gas permeability are possible. Another tested method was annealing/calcination of deposits, which resulted in an increase or decrease of porosity, depending on deposit's chemistry and annealing conditions. Results show that all used post processings are capable of significant changes of deposit microstructure and that they may be successfully applied in practice.

Novel Concept for Totally Integrated Automation (TIA) Using Siemens Bus System and WinCC Online Control

2000 ◽  
Author(s):  
T. Frederking ◽  
R. Gadow
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Data Exchange ◽  
Thermal Spraying ◽  
Software Tool ◽  
Functionally Graded ◽  
Flame Spray ◽  
Total Quality ◽  
Spray Process ◽  
Bus System

Abstract Total quality management requires definite process control as well as online diagnostics, if applied in industrial surface refinement by thermal spraying. A concept for integrated online diagnostics for the high velocity oxygen fuel (HVOF) flame spray process is presented using Siemens S7-300 programmable logic controller and PC-based Siemens WinCC (Windows Control Center) visualization software. The standard functionality of the WinCC programming environment can be extended by C-scripts. The integrated database allows to protocol the relevant process parameters periodically for total quality assurance. Also particle flux imaging software tools can be implemented to adjust online process parameters and for process diagnostic purposes. The Siemens bus system hierarchy thereby provides high speed communication skills for field bus level data exchange and for supervising system components, e.g. CCD-cameras. The interconnection between S7-300 PLC, 6-axis-robot and a novel WinCC software tool enables definite automatic changes of recipes during the coating process to generate functionally graded coatings.

Hybrid Plasma Spraying —Discovering the Effects of Deposition Parameters

2021 ◽  
Author(s):  
Tomas Tesar ◽  
Radek Musalek ◽  
Jan Medricky ◽  
Jan Cizek ◽  
Frantisek Lukac ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Thermal Spraying ◽  
Hybrid Coatings ◽  
Deposition Parameters ◽  
Wide Range ◽  
Hybrid Plasma ◽  
Coating Formation ◽  
Liquid Feedstock ◽  
Multiple Case ◽  
Sprayed Coatings

Abstract Hybrid plasma spraying is emerging as the next potential technology leap in thermal spraying. The combination of high throughput and deposition rates of coatings sprayed from powders with the tailored functionality of liquid-feedstock sprayed coatings appears highly promising for a wide range of applications. Moreover, possible refined mixtures of different materials come readily with the utilization of multiple feedstocks with varying particle sizes. However, the practical aspects of hybrid coatings production are accompanied with several peculiarities not encountered when using distinct feedstocks. To deepen the understanding of this novel route, this paper presents fundamental hybrid coating formation principles and the effect of selected deposition parameters using multiple case-study material systems, such as Al2O3-YSZ, Al2O3-Cr2O3, and Al2O3-TiO2.

scholarly journals Sensitivity of Process Parameters in Atmospheric Plasma Spray Coating

2018 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Biswajit Kumar Swain ◽  
◽  
Soumya Sanjeeb Mohapatra ◽  
Ashutosh Pattanaik ◽  
Sumant Kumar Samal ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Process Parameters ◽  
Spray Coating ◽  
Correct Choice ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
Substrate Roughness ◽  
Working Pressure ◽  
Plasma Gun ◽  
Wide Range

Atmospheric plasma spraying (APS) is one of the most widely used thermal spraying technique which finds a lot of applications due to its versatility of spraying a wide range of materials from metallic to nonmetallic and hence more suitable for spraying of high melting point materials like refractory ceramics material, cermets etc. In recent era,any material can be used for plasma spraying on almost any type of substrate. Process parameters are the key factor that affects the formation of microstructures, bonding of coating with substrate and mechanical strength of coating. In this paper, the process parameters and their sensitivity towards the plasma modified structural elements are discussed.The microstructure of thermally sprayed coatings, which results from the solidification and sintering of the particles, frequently contain pores, oxides and cracks. The amount and distribution of these defects, as well as other coating properties as for instance thickness, hardness and bond strength, will be defined by the selected spray parameters. Therefore, the correct choice of the spray process as well as respective parameters (particle size, particle velocity, spray distance, plasma gun power, working pressure, substrate roughness, substrate temperature and so on) is very important for the deposition of good coatings and, consequently, to enlarge the useful life in service of the components.

Present Status and Future Prospects of Cold Spraying

2007 ◽  
Vol 534-536 ◽  
pp. 433-436 ◽  
Author(s):  
Frank Gaertner ◽  
Tobias Schmidt ◽  
Heinrich Kreye
Keyword(s):  
New Technology ◽  
Thermal Spraying ◽  
Cold Spraying ◽  
Spray Forming ◽  
Full Potential ◽  
Spray Parameters ◽  
Present Contribution ◽  
High Kinetic Energy ◽  
Coating Formation ◽  
New Applications

Cold spraying is a fairly new coating technique, which within the last decade attracted serious attention of research groups and spray companies. As compared to thermal spraying, the low process temperatures in cold spraying result in unique coating properties, which promise new applications. Since particles impact with high kinetic energy in the solid state, new concepts to describe coating formation are requested to enable the full potential of this new technology. The present contribution gives a brief review of current models concerning bonding, supplying a description of the most influential spray parameters and consequences for new developments. With respect to spray forming by cold cold spraying, microstructures and thick, further machineable structures are presented.

scholarly journals Development of Photocatalytic Active TiO2Surfaces by Thermal Spraying of Nanopowders

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Filofteia-Laura Toma ◽  
Ghislaine Bertrand ◽  
Didier Klein ◽  
Cathy Meunier ◽  
Sylvie Begin
Keyword(s):  
Plasma Spraying ◽  
High Performance ◽  
Photocatalytic Performance ◽  
Thermal Spraying ◽  
Environmental Water ◽  
Suspension Plasma Spraying ◽  
Atmospheric Plasma ◽  
Spray Process ◽  
Coating Characteristics ◽  
Titania Coatings

Titanium dioxide is a very useful photocatalyst for the decomposition and diminution of environmental water and air pollutants. In such applications, it can be used as slurry or as immobilized coating obtained by different deposition methods. The studies performed in the last years showed that thermal spraying could be employed to elaborate TiO2coatings with high performance for the decomposition of organic compounds. This manuscript presents a comparative study on the microstructure and photocatalytic performance of titania coatings obtained by different thermal spray techniques: atmospheric plasma spraying (APS), suspension plasma spraying (SPS) and high-velocity oxygen fuel spray process (HVOF). Different titania powders and suspensions were used to study the influence of the feedstock materials on the coating characteristics. The deposits were mainly characterised by SEM and X-ray diffraction. The photocatalytic performance was evaluated from the removal of nitrogen oxides. The experimental results showed that a drastic reduction of the pollutant concentration was obtained in presence of coatings elaborated by suspension plasma spraying. TiO2coatings resulting from the spraying of agglomerated powder presentd less efficiency. That was mainly explained by the significant phase transformation from anatase to rutile that occurred in the enthalpic source during the spray processes.

Coatings characterization of Ni-based alloy applied by HVOF

2018 ◽  
Vol 90 (2) ◽  
pp. 336-343 ◽  
Author(s):  
José Cabral Miramontes ◽  
Gabriela Karina Pedraza Basulto ◽  
Citlalli Gaona Tiburcio ◽  
Patricia Del Carmen Zambrano Robledo ◽  
Carlos Agustín Poblano Salas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
High Performance ◽  
Thermal Spraying ◽  
Advanced Materials ◽  
Oxide Content ◽  
Coating Materials ◽  
Content Type ◽  
Thermal Spray Process ◽  
Spray Process

Purpose The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process. Design/methodology/approach The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties. Findings The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa. Practical implications The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors. Originality/value The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.

Modelling Sequential Impact of Molten Droplets on a Solid Surface in Plasma Spray Process

2011 ◽  
Vol 227 ◽  
pp. 111-115
Author(s):  
Ilhem R. Kriba ◽  
A. Djebaili
Keyword(s):  
Plasma Spray ◽  
High Performance ◽  
Spray Deposition ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Atmospheric Plasma ◽  
Formation Mechanisms ◽  
Temperature Plasma ◽  
Spray Process ◽  
Spraying Process

Plasma spray deposition is one of the most important technologies available for producing the high-performance surfaces required by modern industry. In this process, powder of the coating material is fed into high-temperature plasma, which melts and accelerates the powder; the molten particles subsequently hit and solidify on the surface to be coated. To obtain good quality coating, the powder particle must be at least partially molten and hit the substrate with a high velocity. The flattening characteristics of the droplets impinging on a substrate are important determinants in governing the eventual quality of the plasma spray coating. Different codes have been developed in recent years to simulate the overall thermal spraying process, as well as the growth of the 3D coatings, in which entrained particles are modeled by stochastic particle models, fully coupled to the plasma flow. The present investigation was carried out to have an approach to systematize the atmospheric plasma spraying process in order to create a basis for numerically modeling the plasma dynamics, the coating formation mechanisms and to predict the particle thermo- kinetic state at impact.

Thermal Measurements of Substrate during Spray Processes

1996 ◽  
Author(s):  
O. Brandt ◽  
M. Wandelt
Keyword(s):  
Research Work ◽  
Thermal Spraying ◽  
Infrared Camera ◽  
Powder Materials ◽  
Spray Parameters ◽  
Back Side ◽  
Spray Process ◽  
Measuring Frequency ◽  
Basic Studies ◽  
Aluminum Substrates

Abstract Most research work about thermal spraying involves the special process itself, the spray powder materials and the coatings. The major aim is to clarify the basic relations between different spray parameters and the coating properties, such as bond strength, porosity, wear resistance and residual stress. This paper presents temperature measurements of the substrate while a spray stream is directed at the surface. The substrate temperature was measured with an infrared camera at the back side of a sample. The camera allows a measuring frequency of 4 Hz using 140 by 140 pixel view field. Basic studies were carried out with a High Velocity Oxygen Fuel (HVOF)- System. Typical HVOF parameters were compared while spraying different tungsten carbide alloys on aluminum substrates. Comparative studies with plasma processes were performed. These results should help to calculate the temperature and thermal expansion of real parts with various structures before the spray process is used to apply a coating.

scholarly journals Thermal Spray Processing of Nanostructured Materials

2000 ◽  
Author(s):  
Enrique J. Lavernia
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Sol Gel ◽  
Thermal Spraying ◽  
Nanostructured Material ◽  
Vapor Condensation ◽  
Nanostructured Coatings ◽  
Wide Range ◽  
Sprayed Coatings ◽  
Nanostructured Powders

Abstract The application of nanocrystalline materials used as powder feedstock for thermal spraying in recent years has been mainly facilitated by the wide range of powder sources available, including: vapor condensation, solution precipitation, combustion synthesis, sol-gel processing, thermochemical synthesis, and mechanical alloying/milling. The resultant thermal sprayed coatings have been shown to exhibit unique and often enhanced physical and mechanical performance properties in comparison to the coatings produced by current technology. Improvements in physical have been documented for several metallic and cermet based nanostructured coatings. However, the behavior of a nanostructured material during thermal spraying is rendered complex by factors such as morphology of feedstock powders; thermal stability of nanostructured powders; and thermal and momentum behavior of nanostructured powder. Optimization of chemistry, morphology and coating thickness, for example, should lead to the attainment of physical performance heretofore unattainable with conventional coatings. The present paper is to provide an overview of recent advancements in the field of high performance nanostructured coatings, paying particular attention to underlying fundamental issues. Examples of several metallic and cermet coatings will be used to demonstrate the influence of the morphology of nanostructured powders on the performance of the sprayed coatings.

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