On the Implementation of Neural Network Concept to Optimize Thermal Spray Deposition Process

2001 ◽  
Vol 700 ◽  
Author(s):  
Sofiane Guessasma ◽  
Ghislain Montavon ◽  
Christian Coddet
Keyword(s):  
Plasma Spray ◽  
Numerical Models ◽  
Spray Deposition ◽  
Deposition Process ◽  
Processing Parameters ◽  
Point Of View ◽  
Formation Mechanisms ◽  
Spray Process ◽  
Network Concept ◽  
Coating Formation

AbstractNumerous processing parameters, up to fifty, characterize the plasma spray deposition process. A better quality control of the resulting deposits induces a better understanding of their effects on coating formation mechanisms. Numerical models can help to provide such an understanding. From a mathematical point of view, d.c. plasma spray deposition process is assimilated to a nonlinear problem in regards to its variables (operating parameters, environment, etc.). This paper develops a global approach based on an implicit describing of the mechanisms implementing Artificial Neural Networks (ANNs). The global concept and the protocols to implement are presented and developed for an example related to d.c. plasma spray process.

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.

Effect of Processing Parameters on the Wear Resistance of Thermally Sprayed Epoxy Coatings

1996 ◽  
Author(s):  
Y. Bao ◽  
D.T. Gawne
Keyword(s):  
Wear Resistance ◽  
Heat Flow ◽  
Plasma Spray ◽  
Spray Deposition ◽  
Processing Parameters ◽  
Crosslinking Reaction ◽  
Epoxy Coatings ◽  
Substrate Preheating ◽  
Low Wear ◽  
Thermally Sprayed

Abstract Plasma spray deposition of epoxies under normal conditions produces coatings with low wear resistance. The research shows that the difficulty in achieving satisfactory properties is a result of the rapid heat flow from the coating to the substrate, which suppresses the crosslinking reaction. The results indicate that the use of substrate preheating or ceramic undercoats enhances the wear resistance by promoting the curing reaction during spraying.

Mechanisms of ceramic coating deposition in solution-precursor plasma spray

2002 ◽  
Vol 17 (9) ◽  
pp. 2363-2372 ◽  
Author(s):  
Tania Bhatia ◽  
Alper Ozturk ◽  
Liangde Xie ◽  
Eric H. Jordan ◽  
Baki M. Cetegen ◽  
...  
Keyword(s):  
Plasma Spray ◽  
Deposition Process ◽  
Ceramic Coatings ◽  
Solution Precursor Plasma Spray ◽  
Spray Method ◽  
Solution Precursor ◽  
New Process ◽  
Coating Formation ◽  
Coating Microstructure

The solution-precursor plasma spray (SPPS) method is a new process for depositing thick ceramic coatings, where solution feedstock (liquid) is injected into a plasma. This versatile method has several advantages over the conventional plasma spray method, and it can be used to deposit nanostructured, porous coatings of a wide variety of oxide and non-oxide ceramics for a myriad of possible applications. In an effort to understand the SPPS deposition process, key diagnostic and characterization experiments were performed on SPPS coatings in the Y2O3-stabilized ZrO2 (YSZ) system. The results from these experiments show that there are multiple pathways to SPPS coating formation. The atomized precursor droplets undergo rapid evaporation and breakup in the plasma. This is followed by precipitation, gelation, pyrolysis, and sintering. The different types of particles reach the substrate and are bonded to the substrate or the coating by sintering in the heat of the plasma. The precursor also reaches the substrate or the coating. This precursor pyrolyzes in situ on the substrate, either after it reaches a “cold” substrate or upon contact on a “hot” substrate and helps bond the particles. The coating microstructure evolves during SPPS deposition as the coating temperature reaches approximately 770 °C.

Thermally Sprayed Coating Composites for Film Heating Devices

2006 ◽  
Vol 45 ◽  
pp. 1230-1239 ◽  
Author(s):  
Andreas Killinger ◽  
Rainer Gadow
Keyword(s):  
Thermal Spray ◽  
Spray Deposition ◽  
Deposition Process ◽  
Medium Temperature ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Heating Device ◽  
Layer Structures ◽  
Sprayed Coating ◽  
Thermally Sprayed

Direct heated systems in white goods for medium temperature applications (approx. 250° -350° C) can be applied onto glass, glass ceramic and metal substrates by means of thermal spray techniques. Essentially, such a system requires at least two functional layers to work properly: (1) The metal coating that works as the heating element and (2) an insulator coating that electrically separates the substrate from the film heater. Therefore, the heating device combines three materials (substrate, insulator and film heater) with rather different thermophysical properties. An optimized spray deposition process with proper guidance of the heat flow is required to produce coatings that can operate under cyclic thermal load conditions. The paper discusses the influence of thermal spray process parameters as well as the applied spray powders on the electrical properties of the achieved layer structures of the respective insulator and film heater coatings.

Plasma Spray Deposition of Hydroxyapatite Coatings from Sol Precursors

2007 ◽  
Vol 539-543 ◽  
pp. 1128-1133 ◽  
Author(s):  
Tom W. Coyle ◽  
E. Garcia ◽  
Z. Zhang ◽  
Lu Gan
Keyword(s):  
Particle Size ◽  
Plasma Spray ◽  
Spray Deposition ◽  
Statistical Design ◽  
Deposition Process ◽  
The Body ◽  
Statistical Design Of Experiments ◽  
Deposition Parameters ◽  
Hydroxyapatite Coatings ◽  
Scanning Transmission

Plasma spray deposition of hydroxyapatite (HA) coatings is a well established commercial process. When deposited on metallic substrates, these coatings have been shown to promote bone fixation and osteconductivity. A concern with current coatings is the formation of relatively large debris particles during resorption. The size of the debris is related to the particle size of the powder injected into the plasma during the deposition process. The use of solution precursors or dispersions of fine particle size powders as the feedstock for plasma spraying has been shown to produce submicron/nanocrystalline structured coatings from relatively inexpensive precursors. Nanocrystalline HA coatings may improve the resorption of the coating in the body, avoiding the irritant effect of large particles which may be seen in current thermal sprayed HA coatings. We have explored the use of sols prepared from several different precursors as the feedstock for the plasma spray deposition of HA coatings on Ti6Al4V substrates, employing statistical design of experiments to establish optimal deposition conditions. We report on the formation and the characteristics of the coatings as a function of the deposition parameters. The presence of different Ca-P crystalline and amorphous phases was assessed by X-ray diffraction analysis. The coating microstructure was characterized by scanning/transmission electron microscopy. The suitability of the technique to coat biomedical implants is discussed.

Experimental and simulation approach to plasma spray deposition of yttrium oxide

2012 ◽  
Vol 28 (9) ◽  
pp. 646-656 ◽  
Author(s):  
T K Thiyagarajan ◽  
P V Ananthapadmanabhan ◽  
K P Sreekumar ◽  
Y Chakravarthy ◽  
A K Das ◽  
...  
Keyword(s):  
Yttrium Oxide ◽  
Plasma Spray ◽  
Spray Deposition ◽  
Simulation Approach
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