A Design Review of Ceramic Components for Turbine Engines

1980 ◽  
Vol 102 (2) ◽  
pp. 437-447
Author(s):  
P. J. Coty ◽  
A. D. Lane ◽  
J. B. Lee ◽  
L. J. Meyer
Keyword(s):  
High Performance ◽  
Thermal Stresses ◽  
Ceramic Materials ◽  
Rotor Blades ◽  
Turbine Engines ◽  
Design Concepts ◽  
Component Design ◽  
Path Analyses ◽  
Limited Life ◽  
Ceramic Components

This paper summarizes a program (AFML/APL Contract No. F33615-77-C-5171) to evaluate the application of ceramic materials in small, limited-life turbine engines. Advanced ceramics technology is employed in the program to achieve an affordable, reliable, high-performance capability for turbine engines in a missile application. The paper presents design and material considerations for ceramic rotor blades and stator vanes in addition to aerodynamic flow path analyses for ceramic components in high temperature environments. An iterative materials/design analysis was made with use of probabilistic design methods to predict the survivability of the ceramic components. Materials for both rotor blades and stator vanes were evaluated and selected based on mechanical and thermal stresses imposed by the optimum component design. A number of design concepts for the primary components are reviewed. These concepts include segmented-vane configurations and rotor airfoil shape and attachment schemes.

Design of Ceramic Components for an Advanced Micro-Turbine Engine

2004 ◽  
Author(s):  
Bill Tredway ◽  
Jun Shi ◽  
John Holowczak ◽  
Venkata Vedula ◽  
Connie E. Bird ◽  
...  
Keyword(s):  
Thermal Stresses ◽  
Ceramic Materials ◽  
Turbine Rotor ◽  
Component Reliability ◽  
Turbine Engine ◽  
Component Design ◽  
Temperature Capability ◽  
Ceramic Components ◽  
Micro Turbine ◽  
Engine Components

Ceramic components, due to their high temperature capability, allow significantly higher turbine inlet temperatures with minimal cooling. Hot-section engine components, including combustor, integral vane ring, integrally bladed turbine rotor, and turbine tip shroud were designed for an advanced micro-turbine engine, with special attention to attachment methods that minimize thermal stresses due to large differences between coefficients of thermal expansion between metallic and ceramic materials. Detailed aerodynamic, thermal and stress analyses were performed. Both steady state and transient conditions were evaluated to guide design decisions that lead to optimal component reliability and manufacturability. This paper describes the component design, analysis, and fabrication experiences with silicon based monolithic ceramic materials.

scholarly journals Ceramic Components for Automotive and Heavy Duty Turbine Engines: CATE and AGT 100

1982 ◽  
Author(s):  
H. E. Helms ◽  
J. A. Byrd
Keyword(s):  
Gas Turbine ◽  
Operating Time ◽  
Ceramic Materials ◽  
Turbine Engines ◽  
Aluminum Silicate ◽  
Lithium Aluminum ◽  
Gas Turbine Engines ◽  
Design Component ◽  
Controllable Factors ◽  
Ceramic Components

Detroit Diesel Allison is actively applying advanced ceramic materials to components in gas turbine engines. Silicon carbide, silicon nitride, aluminum silicate, lithium aluminum silicate, and mullite are materials being used in various components in both the DDA GT 404-4 and AGT 100 engines. Approximately 9400 hr of ceramic component operating time in the GT 404 engine has been accumulated, and design, component processing, proof testing, and engine testing experience have begun to show the applicability of ceramic materials in production engines. Material variability, processing procedures, strength characterization, and nondestructive evaluations are emerging as critical but controllable factors. Ceramic components offer the potential of significant fuel consumption improvements in gas turbine engines for vehicles and other applications.

scholarly journals Thermal Strains and Their Effect on the Life of Ceramic Matrix Composite Components in Gas Turbine Engines

1996 ◽  
Author(s):  
Michael J. L. Percival ◽  
Colin P. Beesley
Keyword(s):  
Gas Turbine ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Component Design ◽  
Design Stress

Currently available Ceramic Matrix Composites (CMCs) have very low stress carrying capability if they are to achieve the service life required for application in gas turbine engines. As such, they are most likely to find their first applications in non-structural components with low mechanical loads, where the majority of the stress is thermally induced. The thermal cycling experienced in gas turbine engines, coupled with the necessary interfaces with surrounding metal components and other geometric features, means that these thermal stresses are often localised, but in order to produce a valid component design they may significantly exceed the maximum design stress. The aim of this paper is to discuss the implications for the life of the component of these excess stresses. This will cover the mechanisms for the propagation of localised damage in a strain controlled environment, and the effect of this damage on the thermal conductivity and hence on the induced thermal gradients and thermal strains. Strains corresponding to stresses considerably above the normally accepted design stress can be sustained for a considerable number of cycles, but the influence of extended time periods with damage at elevated temperatures remains unexplored.

scholarly journals Progress in Fabrication of Silicon Nitride Structural Components for Turbomachinery Applications

1996 ◽  
Author(s):  
John P. Pollinger
Keyword(s):  
Silicon Nitride ◽  
High Performance ◽  
Rocket Engine ◽  
Ceramic Materials ◽  
Department Of Energy ◽  
Structural Components ◽  
Technology Program ◽  
Ceramic Components ◽  
Nozzle Blade

The development and refinement of high performance silicon nitride structural ceramic materials over the last five years is leading to evaluation and implementation of components in aircraft, space, industrial, and automotive turbomachinery applications. Current material properties, status of component fabrication technologies, and status of applications being evaluated and commercialized at AlliedSignal Ceramic Components is discussed. Currently achievable properties of in-situ reinforced monolithic silicon nitride materials are presented. The development and status of component forming processes is also discussed, including their potential as manufacturing processes. The processes discussed include slipcasting, green machining, gelcasting, and injection molding. Finally, status of silicon nitride component fabrication and evaluation in a number of applications is discussed, including nozzle, blade, and wheel components for the U.S. Department of Energy (DOE) automotive turbine technology programs, the DOE Advanced Turbine Systems industrial turbine technology program, and a NASA-funded program to develop advanced rocket engine turbopumps.

Ceramic Micro Channel Recuperator Fabrication Methods for Small Gas Turbine Engines

2012 ◽  
Author(s):  
Matthew M. Kelly ◽  
Ming-Jen Pan ◽  
Sundar Atre ◽  
Gregory Rancourt ◽  
Andrew Heyes ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Thermal Stresses ◽  
Fuel Efficiency ◽  
Ceramic Materials ◽  
Metal Alloys ◽  
Turbine Engines ◽  
Complex Structures ◽  
Gas Turbine Engines ◽  
Pressure Chemical

Recuperators can greatly improve the fuel efficiency of gas turbine engines, but they are normally heavy, bulky, expensive, and susceptible to high temperature creep, oxidation, and thermal stresses. One way to alleviate these problems is to make them from ceramic materials rather than metal alloys. However, fabricating these complex structures is a challenge. The technique investigated in this study was to laser-cut thin sheets of tapecast material into complex patterns, laminate them together into stacks, and sinter at high temperature. The layers were laminated together by applying heat, pressure, chemical solvents, and varying combinations of the three. This paper presents the results of all fabrication tests, describes the method used to successfully laminate and sinter one 33-layer stack, and summarizes other possible fabrication techniques for future investigation that would facilitate lamination the process.

scholarly journals Current Status of Industrial and Automotive Ceramic Gas Turbine R&D in Japan

1991 ◽  
Author(s):  
Soichi Nagamatsu ◽  
Kazuyuki Mizuhara ◽  
Yukio Matsuda ◽  
Akio Iwanaga ◽  
Shoji Ishiwata
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Technology Development ◽  
Ceramic Materials ◽  
Current Status ◽  
Inlet Temperature ◽  
Development Organization ◽  
Design Concepts ◽  
Ceramic Components ◽  
Engine Components

The current status of Japan’s national Ceramic Gas Turbines (CGTs) projects is overviewed. The Japanese Ministry of International Trade and Industry (MITI) is conducting two national R&D projects on CGT. These include a project on 300kW industrial CGTs for co-generation and mobile power generation use and a project on 100kW CGT for automotive use. The 300kW project was started in 1988, and is scheduled to develop three kinds of CGTs over nine years. The New Energy and Industrial Technology Development Organization (NEDO) is the main contractor, and three groups of private industries are sub contractors. Three national research institutes are involved in the project to conduct supportive research of ceramic materials and engine components. The 100kW project has started in 1990, and is scheduled to develop a single shaft automotive CGT over seven years. Petroleum Energy Center (PEC) and JARI are the main contractors with the cooperation of several petroleum and automotive companies. The goals for the two projects are 42% and higher for thermal efficiency at a turbine inlet temperature of 1350C. Such targets could not be achieved without applying high temperature ceramics to the engine components. Therefore many R&D objectives are directed towards developing the ceramic components which have a higher flexure strength and fracture toughness. Currently, 300kW base metal gas turbine engines are being developed to prove the design concepts. Blade shapes suitable to ceramics are being studied by the FEM method. Forming and manufacturing large components are also being studied, and some ceramics components have been successfully made.

Examination of Fracture Interfaces in Silicon Nitride

1975 ◽  
Vol 33 ◽  
pp. 60-61
Author(s):  
Nancy J. Tighe
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Grain Boundary Sliding ◽  
Boundary Phase ◽  
Turbine Engines ◽  
Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

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.

Numerical Modeling and Experimental Characterization of the Pyroplasticity in Ceramic Materials during Sintering

2010 ◽  
Vol 62 ◽  
pp. 203-208 ◽  
Author(s):  
Pasquale Bene ◽  
Danilo Bardaro ◽  
Daniela Bello ◽  
Orazio Manni
Keyword(s):  
Ceramic Material ◽  
Ceramic Materials ◽  
Constitutive Law ◽  
Beam Deflection ◽  
Firing Cycle ◽  
Experimental Characterization ◽  
Viscosity Increase ◽  
Ceramic Components ◽  
Deflection Theory ◽  
Sintering Shrinkage

The aim of the work is the study of the pyroplasticity in ceramic materials in order to simulate the deformations of complex ceramic component during sintering. A ceramic material undergoing densification can be treated as a linear viscous material. Generally, the viscosity decreases as the temperature increases, however the densification and the consequent grain growth, result in a viscosity increase. A bending creep test is proposed for measuring the change in viscosity of the ceramic material during densification. Equations, based on beam deflection theory, are derived to determine the viscosity during the whole firing cycle by measuring the deflection in the centre of specimens. In addition, dilatometric analyses are performed to measure the sintering shrinkage and the specimen density, which continuously changes during the sintering process. On the basis of an accurate experimental characterization the parameters of Maxwell viscoelastic constitutive law are derived. A numerical-experimental procedure has been adopted in order to calibrate the numerical model that, finally, has been used to predict the pyroplastic deformations of complex ceramic components.

scholarly journals A Review on the Development of Rotman Lens Antenna

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shruti Vashist ◽  
M. K. Soni ◽  
P. K. Singhal
Keyword(s):  
High Performance ◽  
Beam Steering ◽  
Phase Error ◽  
Antenna System ◽  
Surveillance Systems ◽  
Electronic Warfare ◽  
Design Concepts ◽  
Low Profile ◽  
True Time ◽  
The One

Rotman lenses are the beguiling devices used by the beamforming networks (BFNs). These lenses are generally used in the radar surveillance systems to see targets in multiple directions due to its multibeam capability without physically moving the antenna system. Now a days these lenses are being integrated into many radars and electronic warfare systems around the world. The antenna should be capable of producing multiple beams which can be steered without changing the orientation of the antenna. Microwave lenses are the one who support low-phase error, wideband, and wide-angle scanning. They are the true time delay (TTD) devices producing frequency independent beam steering. The emerging printed lenses in recent years have facilitated the advancement of designing high performance but low-profile, light-weight, and small-size and networks (BFNs). This paper will review and analyze various design concepts used over the years to improve the scanning capability of the lens developed by various researchers.

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