Thermally insulating ceramic coatings also known as thermal barrier coatings (TBCs) have been essential technologies to improve the performance and efficiency of advanced gas turbines in service at extremely high temperatures. The damage mechanisms of air-plasma sprayed YSZ thermal barrier coatings (TBC) with various microstructures were studied by microscopic techniques after thermal cycling. ...

The microstructures of the thermally grown oxide (TGO) in as-coated electron beam physical vapor deposited (EB-PVD) thermal barrier coatings (TBCs) were examined by scanning transmission electron microscopy (STEM) as a function of demonstrated TBC lifetime in a thermally cycled environment. As-coated TBC specimens were selected for analysis based on individual statistical significance in overal...

An air plasma spray process has been used to apply a model tri-layer Yb2SiO5/Al6Si2O13/Si environmental barrier coating system on SiC test coupons. Significant differences in the thermal expansion of the component layers resulted in periodically spaced mud cracks in the Yb2SiO5 and Al6Si2O13 layers. Upon thermal cycling between 1316°C and 110°C in a 90% H2O/10% O2 environment flowing at 4.4 cm/...

Coatings subject to residual compression eventually fail by buckle-driven delamination. The phenomenon is most vivid in thermal barrier coatings (TBCs) used in gas turbines. The failure evolution commences with the formation of a large number of small cracks at geometric imperfections near the interface. These cracks spread upon thermal exposure, particularly upon thermal cycling, because of th...

Thermal barrier coating systems are used on top of highly stressed components in gas turbines to protect the nickel-based substrates. A well-established thermal barrier coating system consist of the bond-coat (BC) and the thermal barrier coating (TBC). A third layer is grown during service: the thermally grown oxide (TGO) between the BC and the TBC. The coatings fail in service because of diffe...

Local residual stress in thermally grown oxide (TGO) layers is the primary cause of failure thermal barrier coating (TBC) systems, especially TBCs prepared by air plasma spray (APS) with a highly irregular TGO. Herein, distribution and evolution TGO layer APS were investigated as function oxidation time. The was measured from cross-sectional micrographs converted to actual inside coatings befor...

Hepatic and extrahepatic insulin sensitivity was assessed in six healthy humans from the insulin infusion required to maintain an 8 mmol/l glucose concentration during hyperglycemic pancreatic clamp with or without infusion of 16.7 micromol. kg(-1). min(-1) fructose. Glucose rate of disappearance (GR(d)), net endogenous glucose production (NEGP), total glucose output (TGO), and glucose cycling ...

Stress development is one of the significant factors leading to the failure of thermal barrier coating (TBC) systems. In this work, stress development in the two phase mixed zone named phase transition layer (PTL), which grows between the thermally grown oxide (TGO) and the bond coat (BC), is investigated by using two different homogenization models. A constitutive equation of the PTL based on ...

The effects of injectable Tunceli garlic oil (Allium tuncelianum) on serum response rainbow trout were examined. Influence intraperitoneal (i.p.) injection administration (TGO) was evaluated some immunological factors trout. Fish weight 40 g i.p. injected TGO at doses 1% and 10%. Serum lysozyme activity, bactericidal myeloperoxidase, protein immunoglobulin levels measured days 3, 7, 14 21 after...

The purpose of this paper is to compute two on one differential game No Escape Zones (NEZ) [8]. The main objective (over the scope of this paper) consists in designing suboptimal strategies in many on many engagements. 1x1 NEZ and 2x1 NEZ are components involved in suboptimal approaches we propose (i.e. “Moving Horizon Hierarchical Decomposition Algorithm” [6]). Several specific two pursuers on...