Recent experimental measurements have revealed that the amplitudes of undulations in the thermally grown oxide (TGO) formed on a bond coat subject to cyclic thermal histories depend on the bond coat thickness, hbc, and exhibit a maximumwhen hbc 100 lm. The existing rumpling model does not predict the maximum. To account for this effect, the model has been extended to include finite substrate th...

Yb2Si2O7/Si environmental barrier coatings (EBCs) were produced by air plasma spray (APS) and low-pressure (LPPS) processes. The phase composition, microstructure, bonding strength of APS LPPS EBCs investigated. Thermal cycling tests performed in steam atmosphere respectively at 1316 °C for both EBCs. There is no coating failure after 900 cycles. In contrast, have an average life 576 cycles a t...

The aim of the study was to investigate Mechanisms properties thermal barrier coatings (TBCs) enhance performance evaluation characteristics and develop TBCs.Cobalt –base superalloy has been used as a substrate zirconium stabilized Aluminum ceramic topcoat , in addition include degradation behavior system during cycling (3hr per cycle furnace) failure aluminized due thermally grown oxide (...

Electron beam (EB) physical vapour deposited (PVD) thermal barrier coatings (TBCs) have been used in gas turbine engines for a number of years. The primary mode of failure is attributed to oxidation of the bondcoat and growth of the thermally grown oxide (TGO), the alumina scale that forms on the bondcoat and to which the ceramic top coat adheres. Once the TGO reaches a critical thickness the T...

Bombardment ofsilicon (100) stIrfaces at room temperature by an oxygen-containing low-energy ion beam is studied as an alternative to thermal oxidation to produce ultrathin oxide films. A self­ limiting oxide thickness of about 50 A is obtained by using ions with energy 100 eV or lower. Auger electron spectroscopy depth profiles of an ion-beam grown oxide and a thermally grown oxide show very s...

The performance of solid oxide fuel cells (SOFCs) can be degraded by “chromium poisoning” where thermally grown Cr2O3 on metallic surfaces forms volatile Cr-containing species that are redeposited active regions the cathode. This phenomenon is further exacerbated for porous interconnects and metal-supported electrodes due to their large surface-to-volume ratios. In this study, electrophoretic d...

In two previous publications (1, 2) it has been shown that thermal oxidation of liquid indium metal droplets gives rise to hollow, hemispherical In203 structures which exhibit maximum quantum efficiencies of 290% at 310 nm. Oxide films of the same mean thickness, grown in essentially the same way except that they were exposed to the oxygen plasma during oxidation gave maximum quantum efficienci...

We provide direct and unambiguous experimental spectroscopic evidence for the structure of a switching oxide trap in thermally grown SiO2 gate oxides on Si. Switching oxide traps can ‘‘switch’’ charge state in response to changes in the voltage applied to the gate of a metal-oxide-semiconductor field-effect transistor. Electron spin resonance measurements reveal that some Eg8 centers ~a hole tr...

In this study, the effect of surface morphologies on the isothermal oxidation behavior of MCrAlY coatings fabricated by high-velocity oxyfuel (HVOF) processes was investigated. To do so, free standing coatings with as-sprayed and polished surfaces were isothermally oxidized at 1050°C. The thickness of the bond coat was approximately 380μm. The Ra of the as-sprayed and polished surfaces were 6.4...