Applying the general effective media (GEM) approach for analyzing the thermal conductivity of ZrO2–8YSZ composites

2018 ◽  
Vol 20 (24) ◽  
pp. 16666-16672 ◽  
Author(s):  
Gal Shekel ◽  
Chen Barad ◽  
Hagay Hayun ◽  
Yatir Sadia ◽  
Yaniv Gelbstein
Keyword(s):  
Thermal Conductivity ◽  
Fuel Cells ◽  
Gas Turbine ◽  
Yttria Stabilized Zirconia ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Stabilized Zirconia ◽  
Effective Media

Zirconia (ZrO2) and yttria-stabilized-zirconia (YSZ) are known as advanced oxides, widely applied in gas-turbine engines, fuel cells and other applications, requiring controlled thermal conductivity values.

Non-Destructive Thermal Barrier Coating Spallation Prediction by a Load-Based Micro-Indentation Technique

2010 ◽  
Author(s):  
J. M. Tannenbaum ◽  
K. Lee ◽  
B. S.-J. Kang ◽  
M. A. Alvin
Keyword(s):  
Thermal Expansion ◽  
Residual Stresses ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Thermal Barrier ◽  
Gas Turbine Engines ◽  
Stabilized Zirconia ◽  
Non Destructive ◽  
Micro Indentation ◽  
Thermally Grown

Currently, the durability and life cycle of thermal barrier coatings (TBC) applied to gas turbine blades and combustor components are limiting the maximum temperature and subsequent efficiency at which gas turbine engines operate. The development of new materials, coating technologies and evaluation techniques is required if enhanced efficiency is to be achieved. Of the current ceramic coating materials used in gas turbine engines, yttria stabilized zirconia (YSZ) is most prevalent, its low thermal conductivity, high thermal expansion coefficient and outstanding mechanical strength make it ideal for use in TBC systems. However, residual stresses caused by coefficients of thermal expansion mismatches within the TBC system and unstable thermally grown oxides are considered the primary causes for its premature and erratic spallation failure. Through finite element simulations, it is shown that the residual stresses generated within the thermally grown oxide (TGO), bond coat (BC), YSZ and their interfaces create slight variations in indentation unloading surface stiffness response prior to spallation failure. In this research, seven air plasma sprayed and one electron beam physical vapor deposition yttria partially stabilized zirconia TBCs were subjected to isothermal and cyclic loadings at 1100°C. The associated coating degradation was evaluated using a non-destructive multiple partial unloading micro-indentation procedure. The results show that the proposed non-destructive micro-indentation evaluation technique can be an effective and specimen-independent TBC failure prediction tool capable of determining the location of initial spallation failure prior to its actual occurrence.

Thermal Barrier Coatings – Why, How, Where and Where To

1998 ◽  
Author(s):  
J. Wigren ◽  
L. Pejryd
Keyword(s):  
Thermal Conductivity ◽  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Thermal Efficiency ◽  
Failure Mechanisms ◽  
Turbine Engines ◽  
Thermal Barrier ◽  
Gas Turbine Engines ◽  
Barrier Coatings

Abstract Thermal barrier coatings are used in several industries to improve thermal efficiency. Examples are gas turbine engines and marine diesels. The performance and life of thermal barrier coated components depend on a variety of factors all related to the specific application. This paper gives an overview of some of the aspects to consider and put special attention to. The different features, in the microstructure, will be discussed with respect to their appearance and influence on the performance of the TBC. Thermal conductivity, microstructure, failure mechanisms and different applications are highlighted.

Gas Screen in Components of Gas Turbine Engines

1997 ◽  
Vol 28 (7-8) ◽  
pp. 536-542
Author(s):  
A. A. Khalatov ◽  
I. S. Varganov
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Screen

Potential Application of Composite Materials to Future Gas Turbine Engines

1988 ◽  
Author(s):  
James C. Birdsall ◽  
William J. Davies ◽  
Richard Dixon ◽  
Matthew J. Ivary ◽  
Gary A. Wigell
Keyword(s):  
Composite Materials ◽  
Gas Turbine ◽  
Potential Application ◽  
Turbine Engines ◽  
Gas Turbine Engines

Method of tribodiagnostics of d-30KU engines/KP with the use of a microwave plasma complex: results of metrological examination and analysis of the accuracy

2020 ◽  
pp. 22-29
Author(s):  
A. Bogoyavlenskiy ◽  
A. Bokov
Keyword(s):  
Gas Turbine ◽  
Microwave Plasma ◽  
Technical Condition ◽  
The State ◽  
Turbine Engines ◽  
Metrological Examination ◽  
Gas Turbine Engines ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Primary Standards

The article contains the results of the metrological examination and research of the accuracy indicators of a method for diagnosing aircraft gas turbine engines of the D30KU/KP family using an ultra-high-frequency plasma complex. The results of metrological examination of a complete set of regulatory documents related to the diagnostic methodology, and an analysis of the state of metrological support are provided as well. During the metrological examination, the traceability of a measuring instrument (diagnostics) – an ultrahigh-frequency plasma complex – is evaluated based on the scintillation analyzer SAM-DT-01–2. To achieve that, local verification schemes from the state primary standards of the corresponding types of measurements were built. The implementation of measures to eliminate inconsistencies identified during metrological examination allows to reduce to an acceptable level the metrological risks of adverse situations when carrying out aviation activities in industry and air transportation. In addition, the probability of occurrence of errors of the first and second kind in the technological processes of tribodiagnostics of aviation gas turbine engines is reduced when implementing a method that has passed metrological examination in real practice. At the same time, the error in determining ratings and wear indicators provides acceptable accuracy indicators and sufficient reliability in assessing the technical condition of friction units of the D-30KP/KP2/KU/KU-154 aircraft engines.

On the prospects of application of nanostructured heterophase polyfunctional composite materials inengine building industry

2019 ◽  
pp. 50-57
Author(s):  
O. B. Silchenko ◽  
M. V. Siluyanova ◽  
V. Е. Nizovtsev ◽  
D. A. Klimov ◽  
A. A. Kornilov
Keyword(s):  
Composite Materials ◽  
Gas Turbine ◽  
Developed Countries ◽  
The United States ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Nanostructured Composite ◽  
Polymer Metal ◽  
Long Operation ◽  
Prospects Of Application

The paper gives a brief review of properties and applications of developed extra-hard nanostructured composite materials and coatings based on them. The presentresearch suggestsaerospace applications of nanostructured composite materials based on carbides, carbonitrides and diboridesof transition and refractory metals. To improve the technical and economic performance of gas turbine engines, it is advisable to use new composite structural materials whose basic physicomechanical properties are several times superior to traditional ones. The greatest progress in developing new composites should be expected in the area of materials created on the basis of polymer, metal, intermetallic and ceramic matrices. Currently components and assemblies of gas turbine engines and multiple lighting power units with long operation life and durability will vigorously develop. Next-generation composites are studied in all developed countries, primarily in the United States and Japan.

scholarly journals Progress in Novel Electrodeposited Bond Coats for Thermal Barrier Coating Systems

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4214
Author(s):  
Kranthi Kumar Maniam ◽  
Shiladitya Paul
Keyword(s):  
Gas Turbine ◽  
Thermal Barrier Coating ◽  
Gas Turbines ◽  
High Performance ◽  
Turbine Engines ◽  
Thermal Barrier ◽  
Gas Turbine Engines ◽  
Potential Cost ◽  
Bond Coats ◽  
Barrier Coating

The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.

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