The Experts below are selected from a list of 45936 Experts worldwide ranked by ideXlab platform
Christian Coddet - One of the best experts on this subject based on the ideXlab platform.
-
In-flight and upon impact particle characteristics modelling in plasma Spray Process
Surface and Coatings Technology, 2010Co-Authors: A.f. Kanta, Marie-pierre Planche, Ghislain Montavon, Christian CoddetAbstract:In Atmospheric plasma Spray Process, the in-flight particle characteristics such as their particle size, velocity and surface temperature influence significantly their flight duration and consequently their melting degree. The knowledge of the correlations between Process parameters and in-flight particle characteristics is very important for optimizing the coating qualities. Artificial neural networks was trained and optimized to establish the relationships linking in-flight particle average diameter and Process parameters to in-flight particle average velocity and surface temperature. Then, the established ANN relationships permitted to determine the in-flight particle average velocity and surface temperature versus their diameter for given Process parameters. These predicted average velocity and surface temperature data were then used to determine the time for complete melting of the particle and its dwell-time before impact by an analytical model for given operating conditions.
-
a three dimensional model of the wire arc Spray Process and its experimental validation
Journal of Materials Processing Technology, 2008Co-Authors: Rodolphe Bolot, Han Lin Liao, Marie-pierre Planche, Christian CoddetAbstract:A CFD study of the twin wire-arc Spray Process is presented in this paper. A three-dimensional model was used to compute the flow inside and outside the Spray gun and gas-particles interactions were computed on the basis of one-way and two-way coupling methods, the latter allowing taking the loading effect into account. The considered particle size distributions were measured experimentally on particles collected at the Spray distance, so that no atomizing model was required. In a second step, the model validation was performed on the basis of comparisons between predictions and particle velocity measurements.
-
transient thermal analysis and coating formation simulation of thermal Spray Process by finite difference method
Surface & Coatings Technology, 2006Co-Authors: Christian CoddetAbstract:A finite difference model for the thermal analysis of the dynamic stochastic multiple particle deposition Process of thermal Spray was developed in this paper. Contrary to the traditional layer-by-layer deposition model, the thermal contribution of individual particles randomly distributed around the Spray jet center was taken into account so as to simulate coating formation Process. New material was dynamically added onto coating/substrate surface with prescribed gun movement. Latent heat effect was introduced by defining the enthalpy of the material as a function of temperature in order to take into account solidification-induced phase change. Real thermal Spray Process can be simulated with adjustable particle size, Spray deposition rate, velocity and movement of the Spray gun, specimen size and cooling conditions, etc.
-
Optimizing the plasma Spray Process parameters of yttria stabilized zirconia coatings using a uniform design of experiments
Journal of Materials Processing Technology, 2005Co-Authors: Jian-feng Li, H. L. Liao, C. X. Ding, Christian CoddetAbstract:The plasma Spray Process parameters of yttria stabilized zirconia coatings with respect to deposition efficiency, porosity and microhardness were investigated using a uniform design of experiments. The measured deposition efficiency, porosity and microhardness of the coatings were regressed as the first- to third-order polynomial equations of five investigated Process parameters, the arc current, argon flow rate, hydrogen flow rate, Spray distance and powder feed rate, using stepwise regression analysis. It was found that the third-order regressed equations were the most appropriate to identify the influences of the investigated Process parameters on the deposition efficiency, porosity and microhardness. Within the scope of the uniform design of experiments, the argon flow rate and the hydrogen flow rate appeared to be the most significant two parameters affecting the deposition efficiency, porosity and microhardness among the five investigated Process parameters. Consequently, despite the fact that the regressed equations were different in terms of elements of the five investigated Process parameters, the porosity decreased and microhardness increased with an increase in the deposition efficiency.
-
relationships between in flight particle characteristics and coating microstructure with a twin wire arc Spray Process and different working conditions
Surface & Coatings Technology, 2004Co-Authors: Marie-pierre Planche, Han Lin Liao, Christian CoddetAbstract:Abstract The aim of this study is to get a better understanding of the build up of coatings obtained through twin wire arc Spray Process. Properties of in-flight steel particles, i.e. diameter, velocity and temperature, were determined using a dpv system, for different working conditions. Due to very large size distribution, specific experimental set-up has been developed in order to collect particles at a given Spraying distance. As a result, the dpv diameter parameter was calibrated and well-marked tendencies on particle velocity and diameter have been found while changing input parameters. Then, the morphology of the splats has been studied in terms of flattening degree and shape factor. Finally, some correlations have been established between input parameters and properties of coatings in relation with particle characteristics and splats analysis.
Marie-pierre Planche - One of the best experts on this subject based on the ideXlab platform.
-
In-flight and upon impact particle characteristics modelling in plasma Spray Process
Surface and Coatings Technology, 2010Co-Authors: A.f. Kanta, Marie-pierre Planche, Ghislain Montavon, Christian CoddetAbstract:In Atmospheric plasma Spray Process, the in-flight particle characteristics such as their particle size, velocity and surface temperature influence significantly their flight duration and consequently their melting degree. The knowledge of the correlations between Process parameters and in-flight particle characteristics is very important for optimizing the coating qualities. Artificial neural networks was trained and optimized to establish the relationships linking in-flight particle average diameter and Process parameters to in-flight particle average velocity and surface temperature. Then, the established ANN relationships permitted to determine the in-flight particle average velocity and surface temperature versus their diameter for given Process parameters. These predicted average velocity and surface temperature data were then used to determine the time for complete melting of the particle and its dwell-time before impact by an analytical model for given operating conditions.
-
Characterization of the wire arc Spray Process via image analysis, in flight particle characteristics and coating properties
High Temperature Material Processes (An International Quarterly of High-Technology Plasma Processes), 2009Co-Authors: Marie-pierre Planche, Ghislain Montavon, H. Liao, C. CoddetAbstract:To have a better understanding of the physical phenomena in wire arc Spraying Process, we investigated droplet formation by discriminating particles resulting from the anode and the cathode wire atomization. The investigation showed that by Spraying simultaneously two different materials, steel and copper, particle trajectory and their diameter distribution, the results related to the Processing parameters. By analyzing the characteristics of captured particles implementing image analyses, the crossover direction of in-flight particles was demonstrated. The droplets produced by the anode were bigger than those issued from the cathode and their fraction number, which was also more important. In addition, some important modifications in particle characteristics were observed by inverting a material by the other at the anode and at the cathode. The melting temperature of copper as anode was a critical parameter and was responsible for the copper vaporization. In-flight particle characteristics (temperature, velocity, and diameter) were also determined by using a Fast-Infrared Pyrometer (FIP DPV2000 type diagnostic system). Concerning particle diameter distribution, a good agreement was discovered for the two approaches (in-flight and a posteriori analyses). Major influences of the electrode nature and the radial location on particle velocity and temperature distribution, was pointed out. Finally, quantitative analyses of coating compositions corroborated previous results. Indeed, the coating thickness distribution was largely dependent on the anode nature. Next, the role of each electrode was related to the droplets formation and thus, optimized operating parameters of the arc Spray Process were deduced.
-
a three dimensional model of the wire arc Spray Process and its experimental validation
Journal of Materials Processing Technology, 2008Co-Authors: Rodolphe Bolot, Han Lin Liao, Marie-pierre Planche, Christian CoddetAbstract:A CFD study of the twin wire-arc Spray Process is presented in this paper. A three-dimensional model was used to compute the flow inside and outside the Spray gun and gas-particles interactions were computed on the basis of one-way and two-way coupling methods, the latter allowing taking the loading effect into account. The considered particle size distributions were measured experimentally on particles collected at the Spray distance, so that no atomizing model was required. In a second step, the model validation was performed on the basis of comparisons between predictions and particle velocity measurements.
-
Modeling of the In-Flight Particles Characteristics Using Neural Networks and Analytical Model
2007Co-Authors: A.f. Kanta, Marie-pierre Planche, Ghislain Montavon, F. CoddetAbstract:In thermal Spray Process, the in-flight particle characteristics such as particle size, velocity and temperature influence significantly their flight duration as well as their melting degree. Consequently, they influence the splat formation and ultimately the coating properties. Thus, the knowledge of the interactions between the Process parameters and the in-flight particle characteristics is very important for optimizing the coating properties. Artificial Neural Network (ANN) concept was used to predict in-flight particle velocity and temperature considering the case of alumina (Al2O3-TiO2) coatings. Databases of in-flight particle characteristics (diameter, velocity and temperature) versus Spray Process parameters (arc current intensity, hydrogen rate and plasma gas composition) were collected. ANN was trained with the database to establish the relationships linking the particle diameter and Spray Process parameters to particle velocity and temperature. Then, the established ANN relationships permitted to determine the inflight particle velocity and temperature versus their diameter for given Spray Process parameters. These velocity and temperature data were then used to determine the time for complete particle melting and the particle dwell-time before impact by an analytical model for given operating conditions.
-
relationships between in flight particle characteristics and coating microstructure with a twin wire arc Spray Process and different working conditions
Surface & Coatings Technology, 2004Co-Authors: Marie-pierre Planche, Han Lin Liao, Christian CoddetAbstract:Abstract The aim of this study is to get a better understanding of the build up of coatings obtained through twin wire arc Spray Process. Properties of in-flight steel particles, i.e. diameter, velocity and temperature, were determined using a dpv system, for different working conditions. Due to very large size distribution, specific experimental set-up has been developed in order to collect particles at a given Spraying distance. As a result, the dpv diameter parameter was calibrated and well-marked tendencies on particle velocity and diameter have been found while changing input parameters. Then, the morphology of the splats has been studied in terms of flattening degree and shape factor. Finally, some correlations have been established between input parameters and properties of coatings in relation with particle characteristics and splats analysis.
Xueqiang Cao - One of the best experts on this subject based on the ideXlab platform.
-
Thermal Ablation of Stabilized Zirconia/Metal Coated Polyimide Matrix Composites Via Plasma Spray Process
Plasma Chemistry and Plasma Processing, 2015Co-Authors: Wenzhi Huang, Haifeng Cheng, Chaoyang Zhang, Yuming Zhou, Xueqiang CaoAbstract:Thermal protection coating systems consisting of different bond coats and stabilized zirconia were fabricated on the silica glass fiber reinforced polyimide matrix composites via air plasma Spray Process. Influence of the different bond coats on thermal ablation resistance of the coating system was investigated. The weight loss of the sample decreased from (7.01 ± 0.42) to (1.93 ± 0.16) %, while the corresponding mass ablation rate of the sample was reduced from 0.48 ± 0.02 to 0.22 ± 0.02 mg s−1, which was attributed to the protection of the coating system with Zn interlayer and partially stabilized zirconia as top layer. After thermal ablation test, failure modes of these coatings were the formation of the cracks or the delamination in the metallic interlayers. Residual stress, thermal stress and further oxidation of the substrate were responsible for the final failure of the coatings.
-
Effect of Bond Coats on Thermal Shock Resistance of Thermal Barrier Coatings Deposited Onto Polymer Matrix Composites Via Air Plasma Spray Process
Journal of Thermal Spray Technology, 2013Co-Authors: Wenzhi Huang, Xizhi Fan, Xiaolong Cai, Xiangsheng Meng, Xueqiang Cao, Yu Zhao, Zhen WangAbstract:Thermal barrier coating systems with different bond coats were fabricated on polymer matrix composites via the air plasma Spray Process. During a thermal shock test at 400 °C, Zn and Al interlayers were helpful in improving the thermal shock resistance of coatings due to the low melting point. The coating system consisted of a soft zinc layer as a bond coat, and YSZ as a top coat exhibited the best thermal shock resistance, attributed to the lower residual stress and lower thermal stress in the Zn interlayer. The failure mechanism of the coating system was mainly ascribable to the residual stress derived from the deposition Process, thermal stress, and further damage of the substrate.
Han Lin Liao - One of the best experts on this subject based on the ideXlab platform.
-
a three dimensional model of the wire arc Spray Process and its experimental validation
Journal of Materials Processing Technology, 2008Co-Authors: Rodolphe Bolot, Han Lin Liao, Marie-pierre Planche, Christian CoddetAbstract:A CFD study of the twin wire-arc Spray Process is presented in this paper. A three-dimensional model was used to compute the flow inside and outside the Spray gun and gas-particles interactions were computed on the basis of one-way and two-way coupling methods, the latter allowing taking the loading effect into account. The considered particle size distributions were measured experimentally on particles collected at the Spray distance, so that no atomizing model was required. In a second step, the model validation was performed on the basis of comparisons between predictions and particle velocity measurements.
-
relationships between in flight particle characteristics and coating microstructure with a twin wire arc Spray Process and different working conditions
Surface & Coatings Technology, 2004Co-Authors: Marie-pierre Planche, Han Lin Liao, Christian CoddetAbstract:Abstract The aim of this study is to get a better understanding of the build up of coatings obtained through twin wire arc Spray Process. Properties of in-flight steel particles, i.e. diameter, velocity and temperature, were determined using a dpv system, for different working conditions. Due to very large size distribution, specific experimental set-up has been developed in order to collect particles at a given Spraying distance. As a result, the dpv diameter parameter was calibrated and well-marked tendencies on particle velocity and diameter have been found while changing input parameters. Then, the morphology of the splats has been studied in terms of flattening degree and shape factor. Finally, some correlations have been established between input parameters and properties of coatings in relation with particle characteristics and splats analysis.
Weifang Su - One of the best experts on this subject based on the ideXlab platform.
-
facile hot solvent vapor annealing for high performance polymer solar cell using Spray Process
Solar Energy Materials and Solar Cells, 2013Co-Authors: Yuching Huang, Houchin Chia, Chihmin Chuang, Chengsi Tsao, Charnying Chen, Weifang SuAbstract:Abstract In this paper, the use of hot solvent vapor (HSV) annealing is demonstrated to improve the performance of polymer solar cells (PSCs) fabricated by the Spray Process. The blend of poly(3-hexylthiophene) and [6,6]-phenyl-C 61 -butyric acid methyl ester (P3HT/PCBM) is used as a photoactive layer of the solar cell. Compared to the conventional solvent vapor annealing, the HSV annealing can eliminate the formation of intra-droplet boundary during the Spray Process and optimize the nanostructure of the film quickly (≤5 min). The study of conducting atomic force microscopy (C-AFM) reveals that the HSV annealed film exhibits smooth film surface and homogenous conductivity distribution. Moreover, an enhanced light harvesting and increased crystallinity of P3HT in the active layer are observed by UV–vis absorption and X-ray diffraction (XRD). With subsequent thermal annealing, the power conversion efficiency of solar cell made from the HSV annealed film is reached at 3.61%. This HSV annealing technique can be implemented into the fabrication of high efficient large-area PSCs using the Spray Process.
