A thermal barrier system with plasma-sprayed thermal barrier coating (TBC) has been analyzed subject to thermal cycling. The thermally grown oxide (TGO) is allowed to grow at the peak temperature in the cycle, with both thickening and lateral components of the growth strain. The stresses in the TGO are also allowed to relax at high temperature when they attain a critical level. The bond coat is...

Thermal barrier coating (TBC) systems are susceptible to delamination failures in the presence of a large thermal gradient. These failures, which occur within the TBC layer, are very different in character from those associated with the thermally grown oxide. Three possible causes of internal delamination are analyzed. In all cases, the thermomechanical properties of the TBC are allowed to vary...

Thermal barrier coating are perceived as an enabling technology to increase the performance of, improve efficiency within, and lower the emissions from, modern gas turbines. To fully utilise this capability one has to be able to accurately predict the life of these coatings under conditions relevant to gas turbine service. This paper addresses the failure of TBC systems as a result of erosion a...

The thermal conductivity of a series of complex aluminates, RE2SrAl2O7, with different rare-earth (RE) ions, has been measured up to 10001C. There is a strong dependence on the atomic number of the RE ion, ranging from an approximately 1/T dependence for the lanthanum strontium aluminate to an almost temperature-independent behavior of the dysprosium strontium aluminate. The latter conductivity...

Following intravenous administration Biliscopin is rapidly excreted, mainly by the liver into the bile. Visualisation of the hepatic and common bile ducts and the gallbladder can, therefore, be achieved. Visualisation of the biliary ducts is usually possible 30-60 minutes after completion of administration. In vitro meglumine iotroxate binds to plasma proteins to the extent of 60-90% depending ...

Recently, barrier certificates have been introduced to prove the safety of continuous or hybrid dynamical systems. A barrier certificate needs to exhibit some barrier function, which partitions the state space in two subsets: the safe subset in which the state can be proved to remain and the complementary subset containing some unsafe region. This approach does not require any reachability anal...

This paper describes a new multilayer TBC that incorporates a 10 μm-thick oxygen barrier layer of yttrium–aluminum garnet (YAG) into a typical YSZ TBC system. The thermal conductivity of as-sprayed YAG/YSZ coatings was reduced due to excessive porosity and amorphous areas in the YAG layer. After long-term heat treatments, the conductivity of the multilayer was unaffected by the presence of YAG....