Thermal barrier sensor coatings - sensing damage and ageing in critical components

2014 ◽  
Author(s):  
C.C. Pilgrim ◽  
S. Berthier ◽  
J.R. Nicholls ◽  
S.K. Biswas ◽  
P.Y. Sollazzo ◽  
...  
Keyword(s):  
Thermal Barrier ◽  
Critical Components

Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

1989 ◽  
Vol 47 ◽  
pp. 426-427
Author(s):  
Ozer Unal
Keyword(s):  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
Ceramic Coating ◽  
High Vacuum ◽  
Ceramic Coatings ◽  
High Energy ◽  
Thermal Barrier ◽  
Protective Oxide ◽  
Barrier Coatings ◽  
Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky
Keyword(s):  
Language Development ◽  
Critical Role ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Children With Asd ◽  
Prevalence Estimates ◽  
Notable Increase ◽  
Screening Assessment ◽  
Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

Faith-Based Health Education Project

2003 ◽  
Vol 1 (2) ◽  
pp. 208-222 ◽  
Author(s):  
Georgia N. L. Johnston
Keyword(s):  
Faith Communities ◽  
Face To Face ◽  
Staff Members ◽  
Community Ownership ◽  
Faith Based ◽  
Program Success ◽  
Project Sustainability ◽  
Critical Components ◽  
Pastoral Support ◽  
Volunteer Commitment

Working with faith communities in health promotion is widely acclaimed and yet not readily practiced. This article describes a study conducted among four faith communities to determine the process required for sustainable faith-based programs. Face-to-face interviews were conducted among 12 community volunteers who participated to identify their perceptions of the project. Two staff members were also interviewed to identify the process from their perspectives. Project-related documents were also analyzed to provide details and triangulate the data from the interviews. The study followed the project for 2 ½ years. Several factors were identified as significant influences on participation and project sustainability. These included value, active pastoral support, program success, and volunteer commitment. The results of this study indicate that pastoral support and faith community ownership are critical components that should be included in faith-based community building efforts.

HOT CORROSION OF CERIA-YTTRIA STABILIZED ZIRCONIA PLASMA SPRAYED THERMAL BARRIER COATING BY EUTECTIC VANDIUM PENTAOXIDE-SODIUM SULFATE

2018 ◽  
Vol 18 (1) ◽  
pp. 182-192 ◽  
Author(s):  
Mohammed J Kadhim ◽  
Mohammed H Hafiz ◽  
Maryam A Ali Bash
Keyword(s):  
Thermal Barrier Coating ◽  
Hot Corrosion ◽  
Monoclinic Phase ◽  
Volume Fraction ◽  
High Volume ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Plan View ◽  
Barrier Coating ◽  
Plasma Sprayed

The high temperature corrosion behavior of thermal barrier coating (TBC) systemconsisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%)bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coatwere characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt%Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC andinteraction times from 1 up to 8 h. The upper surface plan view of the coatings wereidentified for topography, roughness, chemical composition, phases and reaction productsusing scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-raydiffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed thephase transformation of nontransformable tetragonal (t') into monoclinic phase, presence ofYVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed theformation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2.The formation of these compounds were combined with formation of monoclinic phase (m)from transformation of nontransformable tetragonal phase (t').

Evaluation of Spatial Resolution of Nondestructive Testing of Thermal Barrier Coating by Terahertz Imaging

2012 ◽  
Vol 132 (10) ◽  
pp. 864-870
Author(s):  
Tetsuo Fukuchi ◽  
Norikazu Fuse ◽  
Mitsutoshi Okada ◽  
Tomoharu Fujii ◽  
Maya Mizuno ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Thermal Barrier Coating ◽  
Spatial Resolution ◽  
Terahertz Imaging ◽  
Thermal Barrier ◽  
Barrier Coating

Surface Roughness Measurement of Thermal Barrier Coating using Terahertz Waves

2017 ◽  
Vol 137 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Tetsuo Fukuchi ◽  
Norikazu Fuse ◽  
Mitsutoshi Okada ◽  
Tomoharu Fujii ◽  
Maya Mizuno ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Thermal Barrier Coating ◽  
Thermal Barrier ◽  
Roughness Measurement ◽  
Terahertz Waves ◽  
Surface Roughness Measurement ◽  
Barrier Coating

Structure Evolution of 7YSZ Thermal Barrier Coating During Thermal Shock Testing

2015 ◽  
Vol 30 (12) ◽  
pp. 1261
Author(s):  
ZHANG Xiao-Feng ◽  
ZHOU Ke-Song ◽  
ZHANG Ji-Fu ◽  
ZHANG Yong ◽  
LIU Min ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Structure Evolution ◽  
Thermal Barrier ◽  
Shock Testing ◽  
Barrier Coating
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