Integrated Simulation of the Atmospheric Plasma Spraying Process

1998 ◽  
Author(s):  
S. Kundas ◽  
A. Kuzmenkov ◽  
E. Lugscheider ◽  
U. Eritt
Keyword(s):  
Plasma Spraying ◽  
Experimental Verification ◽  
Computer Experiments ◽  
Plasma Jet ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Temperature Dependent ◽  
Integrated Simulation ◽  
Plasma Spraying Process ◽  
Spraying Process

Abstract The main purpose of this work is the development of mathematical and computer models for the integrated simulation of all stages of the atmospheric plasma spraying process (APS) with temperature dependent thermophysical and mechanical properties of the used materials and gases and experimental verification of the simulated results. The following mathematical models of APS were created: particle heating and movement in the plasma jet; coating structure formation; heat transfer and residual stresses in the coating-substrate system. The computer realization of these models enables us to model all stages of APS (integrated or separately). Databases of coating, substrate and plasma-gas substances include the temperature dependent properties. The model of APS is divided in 3 parts, which are connected by continuous data interface. Two dimensional approximation of plasma-gas velocity and temperature in the free plasma jet was used for computation of particle velocity, trajectory and temperature. This information was created with a special Graphic program module and included in database. Computer experiments for plasma spraying of Ah03 and ZrO2+8%Y2O3 in Ar/H2 plasma were carried out. The experimental verification of developed models with High-Velocity-Pyrometry (HVP) and Laser-Doppler- Anemometry (LDA) have shown the satisfactory precision of simulated results.

Correlations Between In-Flight Particle Concentrations and Coating Properties in Atmospheric Plasma Spraying of Alumina

1996 ◽  
Author(s):  
T. Lehtinen ◽  
J. Knuuttila ◽  
J. Vattulainen ◽  
T. Mäntylä ◽  
R. Hernberg
Keyword(s):  
Plasma Spraying ◽  
Powder Particle ◽  
Particle Concentration ◽  
Ccd Camera ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Electrode Wear ◽  
Coating Properties ◽  
Plasma Spraying Process ◽  
Spraying Process

Abstract The plasma spraying process is controlled by various parameters that have an influence on powder particle velocities, temperatures and trajectories just before impact to the substrate. In order to fully utilize the thermal and kinetic energy of the plasma it is important to obtain information from these powder particle properties. In this work an intensified CCD camera has been used to detect in-flight particles in an atmospheric plasma spraying process. Plasma spraying was performed using fused and crushed AI2O3 powder. The powder carrier gas flow rate was varied during the spraying experiments. All the other deposition parameters were kept constant. Coatings produced using relatively new spraygun electrodes are compared with ones produced later with the same electrodes when they were worn out. The particle concentration is determined on a relative scale by the fraction of the area of a CCD camera frame covered by particle images. Further investigations necessary to clearify the relationship between the measured relative particle concentration and the true particle concentration are identified. The coatings are analyzed for wear resistance, degree of melting, deposition efficiency, hardness and porosity. The dependence of these coating properties on the relative particle concentration and the effect of electrode wear on the relative particle concentration are studied.

scholarly journals The Influence of Anode Inner Contour on Atmospheric DC Plasma Spraying Process

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Kui Wen ◽  
Min Liu ◽  
Kesong Zhou ◽  
Xuezhang Liu ◽  
Renzhong Huang ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Thermal Efficiency ◽  
Plasma Jet ◽  
Measured Temperature ◽  
Arc Voltage ◽  
Cylindrical Nozzle ◽  
Jet Characteristics ◽  
Plasma Spraying Process ◽  
Spraying Process ◽  
Plasma Jet Characteristics

In thermal plasma spraying process, anode nozzle is one of the most important components of plasma torch. Its inner contour controls the characteristics of plasma arc/jet, determining the motion and heating behaviors of the in-flight particles and hence influencing the coating quality. In this study, the effects of anode inner contour, standard cylindrical nozzle, and cone-shaped Laval nozzle with conical shape diverging exit (CSL nozzle) on the arc voltage, net power, thermal efficiency, plasma jet characteristics, in-flight particle behaviors, and coating properties have been systematically investigated under atmospheric plasma spraying conditions. The results show that the cylindrical nozzle has a higher arc voltage, net power, and thermal efficiency, as well as the higher plasma temperature and velocity at the torch exit, while the CSL nozzle has a higher measured temperature of plasma jet. The variation trends of the plasma jet characteristics for the two nozzles are comparable under various spraying parameters. The in-flight particle with smaller velocity of CSL nozzle has a higher measured temperature and melting fraction. As a result, the coating density and adhesive strength of CSL nozzle are lower than those of cylindrical nozzle, but the deposition efficiency is greatly improved.

scholarly journals Swirling Effects in Atmospheric Plasma Spraying Process: Experiments and Simulation

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 388
Author(s):  
Israel Martínez-Villegas ◽  
Alma G. Mora-García ◽  
Haideé Ruiz-Luna ◽  
John McKelliget ◽  
Carlos A. Poblano-Salas ◽  
...  
Keyword(s):  
Hydrogen Plasma ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Plasma Stream ◽  
Spray Cone ◽  
Coating Characteristics ◽  
Computational Fluid Dynamics Cfd ◽  
Particles Trajectories ◽  
Plasma Spraying Process ◽  
Spraying Process

Experimental evidence of swirling effects in 3D trajectories of in-flight particles is presented based on static and dynamic footprints analysis as a function of stand-off distance of Al2O3 deposited employing a Metco-9MB torch. Swirling effects were validated with a proprietary computational fluid dynamics (CFD) code that considers an argon-hydrogen plasma stream, in-flight particles trajectories, both creating the spray cone, and particle impact to form a footprint on a fixed substrate located at different distances up to 120 mm. Static and dynamic footprints showed that swirl produces a slight deviation of individual particle trajectories and thus footprint rotation, which may affect coating characteristics.

scholarly journals Structural Changes of Hydroxylapatite during Plasma Spraying: Raman and NMR Spectroscopy Results

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 987
Author(s):  
Robert B. Heimann
Keyword(s):  
Plasma Spraying ◽  
Structural Changes ◽  
Plasma Jet ◽  
Biological Properties ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Decomposition Reactions ◽  
Laser Raman ◽  
Hot Plasma ◽  
Crystallographic Symmetry

Functional osseoconductive coatings based on hydroxylapatite (HAp) and applied preferentially by atmospheric plasma spraying to medical implant surfaces are a mainstay of modern implantology. During contact with the hot plasma jet, HAp particles melt incongruently and undergo complex dehydration and decomposition reactions that alter their phase composition and crystallographic symmetry, and thus, the physical and biological properties of the coatings. Surface analytical methods such as laser-Raman and nuclear magnetic resonance (NMR) spectroscopies are useful tools to assess the structural changes of HAp imposed by heat treatment during their flight along the hot plasma jet. In this contribution, the controversial information is highlighted on the existence or non-existence of oxyapatite, i.e., fully dehydrated HAp as a thermodynamically stable compound.

A model of the interface between plasma jet simulation and the simulation of coating formation during atmospheric plasma spraying (APS)

2004 ◽  
Vol 120 ◽  
pp. 373-380
Author(s):  
E. Lugscheider ◽  
R. Nickel ◽  
N. Papenfuß-Janzen
Keyword(s):  
Heat Transfer ◽  
Plasma Spraying ◽  
Substrate Surface ◽  
Fem Analysis ◽  
Software Tool ◽  
Plasma Jet ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Barrier Coating ◽  
Coating Formation

The atmospheric plasma spraying (APS) process can be divided into sub-processes, which are simulated by different numerical methods. The balance equations of momentum, mass and energy of the plasma jet are solved numerically by applying the finite volume method (FVM) using a CFD (Computational Fluid Dynamics) software tool. On the other hand the solution of the thermo-mechanical problem of the coating formation on the substrate is estimated using the finite element method (FEM). The movement of the plasma jet above the surface of the substrate during the spraying process causes a time dependent boundary condition for the FEM-analysis. The heat transfer from the plasma jet to the substrate has to be taken into account. There is also a mass and heat transfer of heated particles to the substrate surface, which is responsible for the formation of the coating. Not only the plasma jet influences the boundary conditions of the coating formation, but the substrate is also a boundary for the plasma jet. This has to be considered during the plasma jet simulation, as well. This article describes the physical and mathematical background of the plasma jet/substrate heat transfer interface model, the implementation in the overall simulation process and its use in the simulation of the formation of a thermal barrier coating (TBC) made of partially yttria stabilized zirconia on a turbine blade during atmospheric plasma spraying.

Plasma Spray of Free-Standing Components for Bone Tissue Engineering

2008 ◽  
Vol 396-398 ◽  
pp. 695-698
Author(s):  
D. García-Alonso ◽  
T. Levingstone ◽  
M. Parco ◽  
Joseph Stokes
Keyword(s):  
Deposition Time ◽  
Research Work ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
Average Thickness ◽  
Free Standing ◽  
Optimal Values ◽  
Plasma Spraying Process ◽  
Spraying Process

This research work deals with the development of free-standing hydroxyapatite (HA) components produced using the Atmospheric Plasma Spraying Process. The spray parameters were based on the optimal values found in previous work for the HA powder used. The deposition time used to produce the free-standing coupons was varied between 70 and 150 seconds. The influence of spray time on the deposit thickness and the resulting crystallinity of the coupons were investigated. The surface of the samples was characterised by means of SEM and surface roughness was measured using a laser profiler. The crystallinity of the samples was analysed using XRD. The phase content of the coupons was investigated using XRD and Raman Spectroscopy. The crystallinity and thickness of the coupons was found to increase with increasing spray time. A maximum crystallinity of 89% and maximum average thickness of 2.45 mm were obtained.

Role of Atmosphere During Plasma Processing for Application to Plasma Spraying of Aluminum Onto Polyethyleneterephtalate (PET)

1998 ◽  
Author(s):  
H. Hubert ◽  
F. Blein ◽  
A. Freslon ◽  
M. Jeandin ◽  
C. Le Paven ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Detrimental Effect ◽  
Plasma Processing ◽  
Plasma Jet ◽  
Tensile Tests ◽  
Polymeric Substrates ◽  
The Impact ◽  
Plasma Spraying Process ◽  
Spraying Process

Abstract Polymeric substrates have to be severely cooled during the plasma spraying process to limit detrimental effect due to the high heating flow from the plasma jet. The « Atmosphere and Temperature Controlled process » (ATC, patented by CEA) was used to maintain the substrates near room temperature. However, the PET substrates might undergo some superficial modifications which could result from the plasma jet heating and particle heating at the impact. This paper deals with a study of chemical modifications in PET as a function of surrounding atmospheres during plasma processing. Aluminum coating adhesion was determined using tensile tests.

Sign in / Sign up

Export Citation Format

Share Document