The Experts below are selected from a list of 17511 Experts worldwide ranked by ideXlab platform
Benjamin Remy - One of the best experts on this subject based on the ideXlab platform.
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thermal insulation properties of ysz coatings suspension plasma spraying sps versus electron beam physical vapor deposition eb pvd and atmospheric plasma spraying aps
Surface & Coatings Technology, 2017Co-Authors: Benjamin Bernard, Aurélien Joulia, Aurelie Quet, Luc Bianchi, Andre Malie, Vincent Schick, Benjamin RemyAbstract:Abstract Improving efficiency of hot section components of aero engines such as turbine blades or nozzle guide vanes is critical for the aircraft industry. Over many years, the development of advanced Thermal Barrier Coatings (TBCs) has been a field of active research to achieve this purpose. Electron Beam Physical Vapor Deposition (EB-PVD) and Atmospheric Plasma Spraying (APS) processes are widely used to apply TBCs on metal substrates. High costs and rather high thermal conductivities of EB-PVD coatings, as well as low thermal lifetime of APS ones, are real drawbacks for next generations of turbine engines. In this study, Suspension Plasma Spraying (SPS) was assessed to improve TBC thermal properties. It was shown that the SPS process allows to perform Columnar microStructure easily tunable in terms of both compaction of Columnar Structure and thermal conductivity. Thermal conductivities were in the 0.7–1.25 W·m− 1·K− 1 range for SPS coatings while values of 0.9 and 1.5 W·m− 1·K− 1 were measured for APS and EB-PVD coatings, respectively. The effect of heat conduction paths, which impact thermal diffusivity values, was highlighted for the Columnar Structure.
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Columnar suspension plasma sprayed coating microstructural control for thermal barrier coating application
Journal of the European Ceramic Society, 2016Co-Authors: Benjamin Bernard, Aurélien Joulia, Luc Bianchi, Andre Malie, Benjamin RemyAbstract:Suspension plasma spraying (SPS) is used to perform enhanced YSZ coating with Columnar microStructure for thermal barrier coating (TBC) applications. By combination of plasma flow, substrate preparation, suspension formulation and injection or coating kinematic management it is possible to tune SPS coating Structure from widely-separated columns to a significantly more compact Columnar Structure. Among these parameters, substrate roughness control, combined with an adapted coating growth velocity, are identified as the most relevant. An analytical approach is presented to describe columns growth based on coating image analysis. It allows to give the expression of the lateral and normal growth speeds responsible of the Columnar Structure.
Minoru Isshiki - One of the best experts on this subject based on the ideXlab platform.
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influence of substrate bias voltage on properties of pt thin films deposited by non mass separated ion beam deposition method
Materials Letters, 2009Co-Authors: Kouji Mimura, Masahito Uchikoshi, Mitsuhiro Wada, Makoto Ikeda, Minoru IsshikiAbstract:Abstract Pt thin films were deposited on Si substrates by applying a negative substrate bias voltage using a non-mass separated ion beam deposition method. The effect of the substrate bias voltage on the properties of the deposited films was investigated. In the case of Pt thin films deposited without the substrate bias voltage, a Columnar Structure and small grains were observed. The electrical resistivity of the deposited Pt films was very high (49.3 ± 0.65 µΩ cm). By increasing the substrate bias voltage, no clear Columnar Structure was observed. At the substrate bias voltage of − 75 V, the resistivity of the Pt film showed a minimum value of 16.9 ± 0.2 µΩ cm closed to the value of bulk (10.6 µΩ cm).
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effect of substrate bias voltage on the purity of cu films deposited by non mass separated ion beam deposition
Thin Solid Films, 2003Co-Authors: Kouji Mimura, Kiyoshi Miyake, M. Yamashita, Minoru IsshikiAbstract:Abstract Cu films were deposited on Si (1 0 0) substrates at room temperature by a non-mass separated ion beam deposition method. The effect of the negative substrate bias voltage on the property of the Cu films was investigated by using field emission scanning electron microscopy and secondary ion mass spectroscopy. The Cu film deposited at the negative bias voltage of −50 V showed an extremely fine and homogeneous morphology without a Columnar Structure. The purity of the Cu film deposited at the bias voltage of −50 V was much improved in comparison with the 6N Cu target, while the Cu film deposited without applying substrate bias voltage contained more impurities than the 6N Cu target.
Benjamin Bernard - One of the best experts on this subject based on the ideXlab platform.
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thermal insulation properties of ysz coatings suspension plasma spraying sps versus electron beam physical vapor deposition eb pvd and atmospheric plasma spraying aps
Surface & Coatings Technology, 2017Co-Authors: Benjamin Bernard, Aurélien Joulia, Aurelie Quet, Luc Bianchi, Andre Malie, Vincent Schick, Benjamin RemyAbstract:Abstract Improving efficiency of hot section components of aero engines such as turbine blades or nozzle guide vanes is critical for the aircraft industry. Over many years, the development of advanced Thermal Barrier Coatings (TBCs) has been a field of active research to achieve this purpose. Electron Beam Physical Vapor Deposition (EB-PVD) and Atmospheric Plasma Spraying (APS) processes are widely used to apply TBCs on metal substrates. High costs and rather high thermal conductivities of EB-PVD coatings, as well as low thermal lifetime of APS ones, are real drawbacks for next generations of turbine engines. In this study, Suspension Plasma Spraying (SPS) was assessed to improve TBC thermal properties. It was shown that the SPS process allows to perform Columnar microStructure easily tunable in terms of both compaction of Columnar Structure and thermal conductivity. Thermal conductivities were in the 0.7–1.25 W·m− 1·K− 1 range for SPS coatings while values of 0.9 and 1.5 W·m− 1·K− 1 were measured for APS and EB-PVD coatings, respectively. The effect of heat conduction paths, which impact thermal diffusivity values, was highlighted for the Columnar Structure.
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Columnar suspension plasma sprayed coating microstructural control for thermal barrier coating application
Journal of the European Ceramic Society, 2016Co-Authors: Benjamin Bernard, Aurélien Joulia, Luc Bianchi, Andre Malie, Benjamin RemyAbstract:Suspension plasma spraying (SPS) is used to perform enhanced YSZ coating with Columnar microStructure for thermal barrier coating (TBC) applications. By combination of plasma flow, substrate preparation, suspension formulation and injection or coating kinematic management it is possible to tune SPS coating Structure from widely-separated columns to a significantly more compact Columnar Structure. Among these parameters, substrate roughness control, combined with an adapted coating growth velocity, are identified as the most relevant. An analytical approach is presented to describe columns growth based on coating image analysis. It allows to give the expression of the lateral and normal growth speeds responsible of the Columnar Structure.
Hongbo Guo - One of the best experts on this subject based on the ideXlab platform.
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model on thermal conductivity prediction of quasi Columnar Structured coating by plasma spray physical vapor deposition
Ceramics International, 2021Co-Authors: Jia Shi, Shiyi Qiu, Chenguang Huang, Hongbo GuoAbstract:Abstract Firstly, the yttria-stabilized zirconia (YSZ) coating and gadolinium zirconate (GZO) coating with the quasi-Columnar Structure were manufactured by plasma spray physical vapor deposition. At the same time, a novel three-dimensional geometrical model was established that could satisfactorily reflect such quasi-Columnar structural characteristics. Then, based on this model, the three-dimensional spatial distribution of pores and porosity of coatings and the thermal resistance behaviors of the quasi-Columnar Structured coating were analyzed. Later on, the thermodynamic model was established to estimate the thermal conductivity of the quasi-Columnar Structured coatings at different temperatures. Finally, a model for predicting the effective thermal conductivity of the GZO/YSZ double-layer coating with quasi-Columnar Structure was validated to account for the effects of the variable thickness ratios of GZO top layer to YSZ inner layer.
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microStructures of yttria stabilized zirconia coatings by plasma spray physical vapor deposition
Journal of Thermal Spray Technology, 2015Co-Authors: Hongbo Guo, Lihua Gao, Liangliang Wei, Shengkai GongAbstract:As a novel processing technology, plasma spray-physical vapor deposition (PS-PVD) has exhibited potential capability to shape the sprayed coating microStructures. In this paper, yttria-stabilized zirconia (YSZ) coatings were produced at spray distances in the range of 450-1400 mm by PS-PVD. The morphologies of the coatings, going from a denser type of layer to the Columnar Structure, along the axial and radial directions of the plasma plume were studied. Along the axial direction, five YSZ coating microStructures including “dense lamellar Structure,” “closely packed Columnar Structure,” “quasi-Columnar Structure with more nanoparticles,” “EB-PVD-like Columnar Structure,” and “quasi-Columnar Structure with less nanoparticles” were achieved, respectively. Along the radial direction, similar microStructures of coatings were obtained. A simple Structure spatial distribution model was developed for demonstrating the mapping of various YSZ coating microStructures.
Shiyi Qiu - One of the best experts on this subject based on the ideXlab platform.
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model on thermal conductivity prediction of quasi Columnar Structured coating by plasma spray physical vapor deposition
Ceramics International, 2021Co-Authors: Jia Shi, Shiyi Qiu, Chenguang Huang, Hongbo GuoAbstract:Abstract Firstly, the yttria-stabilized zirconia (YSZ) coating and gadolinium zirconate (GZO) coating with the quasi-Columnar Structure were manufactured by plasma spray physical vapor deposition. At the same time, a novel three-dimensional geometrical model was established that could satisfactorily reflect such quasi-Columnar structural characteristics. Then, based on this model, the three-dimensional spatial distribution of pores and porosity of coatings and the thermal resistance behaviors of the quasi-Columnar Structured coating were analyzed. Later on, the thermodynamic model was established to estimate the thermal conductivity of the quasi-Columnar Structured coatings at different temperatures. Finally, a model for predicting the effective thermal conductivity of the GZO/YSZ double-layer coating with quasi-Columnar Structure was validated to account for the effects of the variable thickness ratios of GZO top layer to YSZ inner layer.