The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Louis A. Peluso - One of the best experts on this subject based on the ideXlab platform.
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Role of Environmental Deposits in Spallation of Thermal Barrier Coatings on Aeroengine and Land-Based Gas Turbine Hardware
Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls Diagnostics and Instrumentation; Education; General, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Thermal barrier coating (TBC) spallation on power generation combustors was compared with TBC spallation observed both in military turboshaft engines, and in commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Iron and nickel oxides from turbine components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase.Melting of environmental deposits in conjunction with infiltration was found to result in: densification of the TBC, an increase in its Young’s modulus and an increase in the room temperature compressive stress in the TBC. Delamination of the TBC during thermal cycling is, thereby, attributed to changes in the mechanical properties and associated changes in the stress state of the coating due to infiltration of the environmental deposit.Copyright © 1996 by ASME
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Role of environment deposits and operating surface temperature in spallation of air plasma sprayed thermal barrier coatings
Surface and Coatings Technology, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Spallation of air plasma sprayed (APS) thermal barrier coatings (TBCs) was investigated on power generation combustors, military turboshaft engines, and commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Fe and Ni oxides from metallic components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase. The melting and recrystallization behavior of CMAS deposits was carefully defined by differential thermal analysis.
Marcus P Borom - One of the best experts on this subject based on the ideXlab platform.
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Role of Environmental Deposits in Spallation of Thermal Barrier Coatings on Aeroengine and Land-Based Gas Turbine Hardware
Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls Diagnostics and Instrumentation; Education; General, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Thermal barrier coating (TBC) spallation on power generation combustors was compared with TBC spallation observed both in military turboshaft engines, and in commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Iron and nickel oxides from turbine components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase.Melting of environmental deposits in conjunction with infiltration was found to result in: densification of the TBC, an increase in its Young’s modulus and an increase in the room temperature compressive stress in the TBC. Delamination of the TBC during thermal cycling is, thereby, attributed to changes in the mechanical properties and associated changes in the stress state of the coating due to infiltration of the environmental deposit.Copyright © 1996 by ASME
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Role of environment deposits and operating surface temperature in spallation of air plasma sprayed thermal barrier coatings
Surface and Coatings Technology, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Spallation of air plasma sprayed (APS) thermal barrier coatings (TBCs) was investigated on power generation combustors, military turboshaft engines, and commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Fe and Ni oxides from metallic components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase. The melting and recrystallization behavior of CMAS deposits was carefully defined by differential thermal analysis.
Curtis A. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Role of Environmental Deposits in Spallation of Thermal Barrier Coatings on Aeroengine and Land-Based Gas Turbine Hardware
Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls Diagnostics and Instrumentation; Education; General, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Thermal barrier coating (TBC) spallation on power generation combustors was compared with TBC spallation observed both in military turboshaft engines, and in commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Iron and nickel oxides from turbine components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase.Melting of environmental deposits in conjunction with infiltration was found to result in: densification of the TBC, an increase in its Young’s modulus and an increase in the room temperature compressive stress in the TBC. Delamination of the TBC during thermal cycling is, thereby, attributed to changes in the mechanical properties and associated changes in the stress state of the coating due to infiltration of the environmental deposit.Copyright © 1996 by ASME
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Role of environment deposits and operating surface temperature in spallation of air plasma sprayed thermal barrier coatings
Surface and Coatings Technology, 1996Co-Authors: Marcus P Borom, Curtis A. Johnson, Louis A. PelusoAbstract:Spallation of air plasma sprayed (APS) thermal barrier coatings (TBCs) was investigated on power generation combustors, military turboshaft engines, and commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature Molten Phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the Molten Phase that infiltrates the TBC microstructure. Fe and Ni oxides from metallic components and zirconia and yttria from the TBC were also found in varying amounts in the Molten Phase. The melting and recrystallization behavior of CMAS deposits was carefully defined by differential thermal analysis.
Daisuke Eto - One of the best experts on this subject based on the ideXlab platform.
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Measurement of Optical Constants for Molten Phase-Change Thin Film
Japanese Journal of Applied Physics, 2008Co-Authors: Daisuke Eto, Kazuhiko Aoki, Shuichi OhkuboAbstract:The measurement of optical constants for Molten Phase-change thin film is a key issue in designing super-resolution media. We have succeeded in the stable measurement for the first time. In our measurements, Phase-change thin film was sandwiched between metal oxide protective thin films, which remain stable over the melting point of Phase-change material. The stability of this measurement was confirmed by the repeatability of the temperature dependence of transmittance and reflectance, and transmission electron microscopy (TEM) observation.
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Temperature dependence of optical constants for InSb films including Molten Phases
Applied Physics Letters, 2008Co-Authors: Shuichi Ohkubo, Kazuhiko Aoki, Daisuke EtoAbstract:We have measured the temperature dependence of optical constants of InSb films including Molten Phases. It has been found that the optical constants differ between the as-sputtered amorphous and the Molten states. Also, the optical constants exhibit the large change associated with the crystalline-to-Molten Phase transition. In the crystalline states, the extinction coefficient increases as the temperature increases. This temperature dependence can be explained by the decrease of the band gap energy.
J.l. Lacout - One of the best experts on this subject based on the ideXlab platform.
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Study of the Ca/P atomic ratio of the amorphous Phase in plasma-sprayed hydroxyapatite coatings
Journal of Solid State Chemistry, 2003Co-Authors: M.t. Carayon, J.l. LacoutAbstract:Because of the excellent biocompatibility of hydroxyapatite (HAp), plasma-sprayed HAp is widely used to coat orthopedic protheses. During the plasma spraying process, the thermal decomposition of HAp products tricalcium phosphate (TCP), tetracalcium phosphate (TeCP), calcium oxide (CaO), oxyhydroxyapatite (OxyHAp) and a Molten Phase. Hence, the coating is made of different Phases including TCP, TeCP, CaO, OxyHAp, HAp and an amorphous Phase. According to AFNOR standards, 35 samples of plasma-sprayed HAp coatings were analyzed by X-ray diffraction. The weight fraction of each Phase (TCP, TeCP, CaO, HAp and amorphous Phase) was measured with calibration curves. Thus, the Ca/P atomic ratio of the amorphous Phase was calculated, the different ratios were between 1.50 and 1.67. The Ca/P atomic ratio of the amorphous Phase varies both with the quantity of TCP or TeCP solubilized in the Molten Phase and with the part of TCP and TeCP which crystallizes from the amorphous Phase during cooling.