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Bernard Pateyron - One of the best experts on this subject based on the ideXlab platform.

  • Protective Plasma Sprayed Coating forThermo-Sensitive Substrates
    MATEC Web of Conferences, 2020
    Co-Authors: Soufiane Oukach, H. Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    Plasma spray is one of the surface treatment techniques that consist on the deposition of a thin coating onto a targeted substrate. Coating is built up by successive accumulation of layered splats resulting from impact and solidification of Molten Particles into thin ‘‘splats’’ onto the substrate. The process of droplet impact, spreading and solidification is then a crucial process in coating formation. This technique may be also used for thermo-sensitive materials such as wood by applying a metallic coating for protective or decorative purposes. However, when applying a ceramic coating which provides a high protection against hot temperatures like fire, wood may be damaged because of the high temperature at which the ceramic Molten Particles arrive at the substrate. In this paper, a numerical simulation based on the Finite Elements Method is carried out in order to simulate the process of the first splat formation onto a wood substrate under traditional plasma spraying conditions. The computations are carried out on a fixed eulerian structured mesh using the level set method to track the interface between the Molten Particle and surrounding gas. The effects of operating conditions as well as the droplet characteristics that allow applying ceramic coating onto a wood substrate without any damage to this thermo-sensitive material are investigated.

  • Numerical study of the spreading and solidification of a Molten Particle impacting onto a rigid substrate under plasma spraying conditions
    Thermal Science, 2015
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    This paper deals with simulation of the spreading and solidification of a fully Molten Particle impacting onto a preheated substrate under traditional plasma spraying conditions. The multiphase problem governing equations of mass, momentum and energy conservation taking into account heat transfer by conduction, convec-tion, and phase change are solved by using a finite element approach. The interface between Molten Particle and surrounding air, is tracked using the Level Set method. The effect of the Reynolds number on the droplet spreading and solidification, using a wide range of impact velocities (40-250 m/s), is reported. A new correlation that predicts the final spread factor of splat as a function of Reynolds number is obtained. Thermal contact resistance, viscous dissipation, wettability and surface tension forces effects are taken into account.

  • Thermo-mechanical modeling of the splat formation in plasma spray conditions
    Physical and Chemical News, 2013
    Co-Authors: Soufiane Oukach, Mohammed El Ganaoui, H. Hamdi, Bernard Pateyron
    Abstract:

    The present study focuses on the modeling and simulation of the process of impact and solidification of a Molten alumina Particle onto a substrate under plasma spray conditions. It aims at a better understanding of the different mechanisms that govern the formation of a single splat resulting from the impact of a Particle onto a substrate. The successive stacking of these splats leads to the coating formation. The main objective is to examine the influence of the nature of the substrate and its initial temperature on the formation of a splat. The model is based on the Navier-Stokes and energy equations coupled with the "Level Set" function which permits tracking of the interface between Molten Particle and surrounding air. These equations are solved by the finite element method using Comsol Multiphysics software. The effects of surface tension forces, wettability and thermal contact resistance are taken into account.

  • Thermal Effects on the Spreading and Solidification of a Micrometric Molten Particle Impacting onto a Rigid Substrate
    2012
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    Abstract: The splat formation is one of the basic processes in thermal spray coat-ings. The performance of these coatings is strongly related to the process of spread-ing and solidification of Molten droplets. The aim of the present paper is to simu-late the fluid flow, heat transfer and phase-change that occur when a micrometricMolten droplet impacts onto a rigid substrate and to examine the effect of the sub-strate conditions, such as initial temperature and material on the solidification timeand spreading process. The effect of thermal contact resistance is also investigated.The simulation model used is based on the Navier-Stokes equations and the energyequation which includes convection and phase change. These equations are cou-pled with the Level Set function to track the interface between Molten Particle andsurrounding air. The numerical model is solved using Finite Element Method andComsol multiphysics 3.5a software.Keywords: droplet impact, solidification, multiphase flow, level set, and thermalcontact resistance.1 IntroductionDespite of being studied over a century [Worthington (1876),Worthington (1877)],the process of droplets impingement on solids surfaces continues to be a challeng-ing problem for engineers and scientists due to its relevance to many industrial andengineering applications such as thermal spray, fuel combustion, ink-jet printing,painting and so on. In thermal spray technology, coatings are obtained by injecting

  • Thermal effects on the spreading and solidification of a micrometric Molten Particle impacting onto a rigid substrate
    Fluid Dynamics and Materials Processing, 2012
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    The splat formation is one of the basic processes in thermal spray coatings.The performance of these coatings is strongly related to the process of spreading and solidification of Molten droplets. The aim of the present paper is to simulate the fluid flow, heat transfer and phase-change that occur when a micrometric Molten droplet impacts onto a rigid substrate and to examine the effect of the substrate conditions, such as initial temperature and material on the solidification time and spreading process. The effect of thermal contact resistance is also investigated.The simulation model used is based on the Navier-Stokes equations and the energy equation which includes convection and phase change. These equations are coupled with the Level Set function to track the interface between Molten Particle and surrounding air. The numerical model is solved using Finite Element Method and Comsol multiphysics 3.5a software

Wei Cheng Lih - One of the best experts on this subject based on the ideXlab platform.

  • effects of process parameters on Molten Particle speed and surface temperature and the properties of hvof crc nicr coatings
    Surface & Coatings Technology, 2000
    Co-Authors: Wei Cheng Lih, I. C. Hsu, S C Huang, S H Yang, Mingsheng Leu
    Abstract:

    Abstract Chromium Carbide/Nickel-Chrome is a good wear resistant coating at elevated temperatures up to 850°C. High velocity oxy-fuel (HVOF) is a promising process for preparation of the CrC/NiCr coatings. During thermal spray process, the speed and surface temperature of in-flight Molten Particles are two key factors affecting the sprayed coating quality. Coating deposited by higher kinetic energy and adequate surface temperature Molten Particles is expected to be dense and hard. In this study, the influences of HVOF process parameters on Molten Particle speed and surface temperature, and the properties of prepared CrC/NiCr coatings were subjected to a DOE investigation. According to the experimental results, the major control factors affecting Particle temperature are powder feed rate, stand-off distance and gun barrel length. Stand-off distance and oxygen flow rate are major factors affecting Particle speed. Based on the evaluated specimens, porosity contents of all the prepared coatings are less than one percent, and coatings deposited by Molten Particles heated to range of 1650°C–1725°C showed relatively lower porosity contents. Coatings deposited by higher Particle speed exhibited relatively better abrasion-wear resistance.

  • Effects of process parameters on Molten Particle speed and surface temperature and the properties of HVOF CrC/NiCr coatings
    Surface and Coatings Technology, 2000
    Co-Authors: Wei Cheng Lih, I. C. Hsu, C. Y. Su, S C Huang, Size Yang, M. S. Leu
    Abstract:

    Chromium Carbide/Nickel-Chrome is a good wear resistant coating at elevated temperatures up to 850 °C. High velocity oxy-fuel (HVOF) is a promising process for preparation of the CrC/NiCr coatings. During thermal spray process, the speed and surface temperature of in-flight Molten Particles are two key factors affecting the sprayed coating quality. Coating deposited by higher kinetic energy and adequate surface temperature Molten Particles is expected to be dense and hard. In this study, the influences of HVOF process parameters on Molten Particle speed and surface temperature, and the properties of prepared CrC/NiCr coatings were subjected to a DOE investigation. According to the experimental results, the major control factors affecting Particle temperature are powder feed rate, stand-off distance and gun barrel length. Stand-off distance and oxygen flow rate are major factors affecting Particle speed. Based on the evaluated specimens, porosity contents of all the prepared coatings are less than one percent, and coatings deposited by Molten Particles heated to range of 1650 °C-1725 °C showed relatively lower porosity contents. Coatings deposited by higher Particle speed exhibited relatively better abrasion-wear resistance.

Soufiane Oukach - One of the best experts on this subject based on the ideXlab platform.

  • Protective Plasma Sprayed Coating forThermo-Sensitive Substrates
    MATEC Web of Conferences, 2020
    Co-Authors: Soufiane Oukach, H. Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    Plasma spray is one of the surface treatment techniques that consist on the deposition of a thin coating onto a targeted substrate. Coating is built up by successive accumulation of layered splats resulting from impact and solidification of Molten Particles into thin ‘‘splats’’ onto the substrate. The process of droplet impact, spreading and solidification is then a crucial process in coating formation. This technique may be also used for thermo-sensitive materials such as wood by applying a metallic coating for protective or decorative purposes. However, when applying a ceramic coating which provides a high protection against hot temperatures like fire, wood may be damaged because of the high temperature at which the ceramic Molten Particles arrive at the substrate. In this paper, a numerical simulation based on the Finite Elements Method is carried out in order to simulate the process of the first splat formation onto a wood substrate under traditional plasma spraying conditions. The computations are carried out on a fixed eulerian structured mesh using the level set method to track the interface between the Molten Particle and surrounding gas. The effects of operating conditions as well as the droplet characteristics that allow applying ceramic coating onto a wood substrate without any damage to this thermo-sensitive material are investigated.

  • Numerical study of the spreading and solidification of a Molten Particle impacting onto a rigid substrate under plasma spraying conditions
    Thermal Science, 2015
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    This paper deals with simulation of the spreading and solidification of a fully Molten Particle impacting onto a preheated substrate under traditional plasma spraying conditions. The multiphase problem governing equations of mass, momentum and energy conservation taking into account heat transfer by conduction, convec-tion, and phase change are solved by using a finite element approach. The interface between Molten Particle and surrounding air, is tracked using the Level Set method. The effect of the Reynolds number on the droplet spreading and solidification, using a wide range of impact velocities (40-250 m/s), is reported. A new correlation that predicts the final spread factor of splat as a function of Reynolds number is obtained. Thermal contact resistance, viscous dissipation, wettability and surface tension forces effects are taken into account.

  • Thermo-mechanical modeling of the splat formation in plasma spray conditions
    Physical and Chemical News, 2013
    Co-Authors: Soufiane Oukach, Mohammed El Ganaoui, H. Hamdi, Bernard Pateyron
    Abstract:

    The present study focuses on the modeling and simulation of the process of impact and solidification of a Molten alumina Particle onto a substrate under plasma spray conditions. It aims at a better understanding of the different mechanisms that govern the formation of a single splat resulting from the impact of a Particle onto a substrate. The successive stacking of these splats leads to the coating formation. The main objective is to examine the influence of the nature of the substrate and its initial temperature on the formation of a splat. The model is based on the Navier-Stokes and energy equations coupled with the "Level Set" function which permits tracking of the interface between Molten Particle and surrounding air. These equations are solved by the finite element method using Comsol Multiphysics software. The effects of surface tension forces, wettability and thermal contact resistance are taken into account.

  • Thermal Effects on the Spreading and Solidification of a Micrometric Molten Particle Impacting onto a Rigid Substrate
    2012
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    Abstract: The splat formation is one of the basic processes in thermal spray coat-ings. The performance of these coatings is strongly related to the process of spread-ing and solidification of Molten droplets. The aim of the present paper is to simu-late the fluid flow, heat transfer and phase-change that occur when a micrometricMolten droplet impacts onto a rigid substrate and to examine the effect of the sub-strate conditions, such as initial temperature and material on the solidification timeand spreading process. The effect of thermal contact resistance is also investigated.The simulation model used is based on the Navier-Stokes equations and the energyequation which includes convection and phase change. These equations are cou-pled with the Level Set function to track the interface between Molten Particle andsurrounding air. The numerical model is solved using Finite Element Method andComsol multiphysics 3.5a software.Keywords: droplet impact, solidification, multiphase flow, level set, and thermalcontact resistance.1 IntroductionDespite of being studied over a century [Worthington (1876),Worthington (1877)],the process of droplets impingement on solids surfaces continues to be a challeng-ing problem for engineers and scientists due to its relevance to many industrial andengineering applications such as thermal spray, fuel combustion, ink-jet printing,painting and so on. In thermal spray technology, coatings are obtained by injecting

  • Thermal effects on the spreading and solidification of a micrometric Molten Particle impacting onto a rigid substrate
    Fluid Dynamics and Materials Processing, 2012
    Co-Authors: Soufiane Oukach, Hassan Hamdi, Mohammed El Ganaoui, Bernard Pateyron
    Abstract:

    The splat formation is one of the basic processes in thermal spray coatings.The performance of these coatings is strongly related to the process of spreading and solidification of Molten droplets. The aim of the present paper is to simulate the fluid flow, heat transfer and phase-change that occur when a micrometric Molten droplet impacts onto a rigid substrate and to examine the effect of the substrate conditions, such as initial temperature and material on the solidification time and spreading process. The effect of thermal contact resistance is also investigated.The simulation model used is based on the Navier-Stokes equations and the energy equation which includes convection and phase change. These equations are coupled with the Level Set function to track the interface between Molten Particle and surrounding air. The numerical model is solved using Finite Element Method and Comsol multiphysics 3.5a software

M. S. Leu - One of the best experts on this subject based on the ideXlab platform.

  • Effects of process parameters on Molten Particle speed and surface temperature and the properties of HVOF CrC/NiCr coatings
    Surface and Coatings Technology, 2000
    Co-Authors: Wei Cheng Lih, I. C. Hsu, C. Y. Su, S C Huang, Size Yang, M. S. Leu
    Abstract:

    Chromium Carbide/Nickel-Chrome is a good wear resistant coating at elevated temperatures up to 850 °C. High velocity oxy-fuel (HVOF) is a promising process for preparation of the CrC/NiCr coatings. During thermal spray process, the speed and surface temperature of in-flight Molten Particles are two key factors affecting the sprayed coating quality. Coating deposited by higher kinetic energy and adequate surface temperature Molten Particles is expected to be dense and hard. In this study, the influences of HVOF process parameters on Molten Particle speed and surface temperature, and the properties of prepared CrC/NiCr coatings were subjected to a DOE investigation. According to the experimental results, the major control factors affecting Particle temperature are powder feed rate, stand-off distance and gun barrel length. Stand-off distance and oxygen flow rate are major factors affecting Particle speed. Based on the evaluated specimens, porosity contents of all the prepared coatings are less than one percent, and coatings deposited by Molten Particles heated to range of 1650 °C-1725 °C showed relatively lower porosity contents. Coatings deposited by higher Particle speed exhibited relatively better abrasion-wear resistance.

Mingsheng Leu - One of the best experts on this subject based on the ideXlab platform.

  • effects of process parameters on Molten Particle speed and surface temperature and the properties of hvof crc nicr coatings
    Surface & Coatings Technology, 2000
    Co-Authors: Wei Cheng Lih, I. C. Hsu, S C Huang, S H Yang, Mingsheng Leu
    Abstract:

    Abstract Chromium Carbide/Nickel-Chrome is a good wear resistant coating at elevated temperatures up to 850°C. High velocity oxy-fuel (HVOF) is a promising process for preparation of the CrC/NiCr coatings. During thermal spray process, the speed and surface temperature of in-flight Molten Particles are two key factors affecting the sprayed coating quality. Coating deposited by higher kinetic energy and adequate surface temperature Molten Particles is expected to be dense and hard. In this study, the influences of HVOF process parameters on Molten Particle speed and surface temperature, and the properties of prepared CrC/NiCr coatings were subjected to a DOE investigation. According to the experimental results, the major control factors affecting Particle temperature are powder feed rate, stand-off distance and gun barrel length. Stand-off distance and oxygen flow rate are major factors affecting Particle speed. Based on the evaluated specimens, porosity contents of all the prepared coatings are less than one percent, and coatings deposited by Molten Particles heated to range of 1650°C–1725°C showed relatively lower porosity contents. Coatings deposited by higher Particle speed exhibited relatively better abrasion-wear resistance.