Development of Ultra High Temperature Ceramic Composites for Gas Turbine Combustors

1997 ◽  
Author(s):  
Magnus Holmquist ◽  
Robert Lundberg ◽  
Tony Razzell ◽  
Olivier Sudre ◽  
Ludovic Molliex ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Recent Progress ◽  
Scale Up ◽  
Life Time ◽  
Ceramic Composites ◽  
Oxide Ceramic ◽  
Property Evaluation ◽  
Oxide Fibres ◽  
Oxide Composites

All-oxide ceramic composites as a material with potential for long life-time applications at temperatures in the 1400–1600°C range in combustion environments were studied. The properties of available polycrystalline and single crystal oxide fibres were summarised. The literature on stable weak interfaces in all-oxide composites was reviewed. Composites with single crystal fibres, a polycrystalline matrix of the same material as the fibres, and a compatible high temperature stable weak oxide interphase was suggested to be the most promising approach. Recent progress in an ongoing European project aiming at development, scale-up and property evaluation of all-oxide composites is reported. The composite will be applied to a simple prototype combustor tile and tested in a combustor rig.

scholarly journals Injection Moulding of Oxide Ceramic Matrix Composites: Comparing Two Feedstocks

2019 ◽  
Vol 809 ◽  
pp. 140-147 ◽  
Author(s):  
Maike Böttcher ◽  
Daisy Nestler ◽  
Jonas Stiller ◽  
Lothar Kroll
Keyword(s):  
High Temperature ◽  
Injection Moulding ◽  
Ceramic Matrix ◽  
Ceramic Composites ◽  
Laboratory Scale ◽  
Oxide Ceramic ◽  
Scale Production ◽  
Oxide Ceramics ◽  
Moulding Process ◽  
Injection Moulding Process

Ceramic materials are suitable for use in the high temperature range. Oxide ceramics, in particular, have a high potential for long-term applications under thermal cycling and oxidising atmosphere. However, monolithic oxide ceramics are unsuitable for use in high-temperature technical applications because of their brittleness. Thin-walled, oxidation resistant, and high-temperature resistant materials can be developed by reinforcing oxide ceramics with ceramic fibres such as alumina fibres. The increase of the mechanical stability of the composites in comparison to the non-fibre reinforced material is of outstanding importance. Possible stresses or cracks can be derived along the fibre under mechanical stress or deformation. Components made of fibre-reinforced ceramic composites with oxide ceramic matrix (OCMC) are currently produced in manual and price-intensive processes for small series. Therefore, the manufacturing should be improved. The ceramic injection moulding (CIM) process is established in the production of monolithic oxide ceramics. This process is characterised by its excellent automation capability. In order to realise large scale production, the CIM-process should be transferred to the production of fibre-reinforced oxide ceramics. The CIM-process enables the production of complicated component shapes and contours without the need for complex mechanical post-treatment. This means that components with complex geometries can be manufactured in large quantities.To investigate the suitability of the injection moulding process for the production of OCMCs, two different feedstocks and alumina fibres (Nextel 610) were compounded in a laboratory-scale compounder. The fibre volume fractions were varied. In a laboratory-scale injection moulding device, microbending specimens were produced from the compounds obtained in this way. To characterise the test specimens, microstructure examinations and mechanical-static tests were done. It is shown that the injection moulding process is suitable for the production of fibre-reinforced oxide ceramics. The investigations show that the feedstocks used have potential for further research work and for future applications as material components for high-temperature applications in oxidising atmospheres.

High Temperature Characteristics of Melt Growth Composites and Their Application to Ultra High Efficiency Gas Turbine Components

2006 ◽  
Vol 317-318 ◽  
pp. 473-480 ◽  
Author(s):  
Yoshiharu Waku
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Gas Turbine ◽  
Binary Systems ◽  
High Efficiency ◽  
Ceramic Composites ◽  
High Temperature Strength ◽  
Melt Growth ◽  
Air Atmosphere ◽  
High Temperature Structural Material

Much attention has been paid to unidirectionally solidified ceramic composites as a candidate for a high-temperature structural material. We have recently developed eutectic composites, which are named as Melt Growth Composites (MGCs). The binary MGCs (Al2O3/YAG and Al2O3/GAP binary systems) have a novel microstructure, in which continuous networks of single-crystal Al2O3 phases and single-crystal oxide compounds (YAG or GAP) interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, superior oxidation resistance and thermal stability in an air atmosphere at very high temperatures. Manufacturing processes for the MGCs are being examined under a Japanese national project, scheduled from 2001 - 2005. To achieve higher thermal efficiency for gas turbine systems, a bowed stacking nozzle vane has been fabricated on an experimental basis.

scholarly journals Optimization of Alumina Slurry for Oxide-Oxide Ceramic Composites Manufactured by Injection Molding

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Catherine Billotte ◽  
Edith Roland Fotsing ◽  
Edu Ruiz
Keyword(s):  
Nitric Acid ◽  
Ceramic Composites ◽  
Oxide Ceramic ◽  
Structure Development ◽  
Rheological Study ◽  
Stable Suspension ◽  
Production Constraints ◽  
Low Viscosity ◽  
Oxide Composites ◽  
Newtonian Behavior

This paper focuses on the rheological study of an alumina suspension intended for the manufacturing of oxide-oxide composites by flexible injection. Given the production constraints, it is required to have stable suspension with low viscosity and a Newtonian behavior. This is achieved with a concentration of nitric acid between 0.08 wt% and 0.2 wt% and amount of 3 wt% of PVA binder. The maximum loading of the suspension of 47 vol% suggests that there is no structure development within the suspension with optimized concentration of acid and PVA.

Development of Near-Net Shape Casting Technology for MGC Components

2005 ◽  
Author(s):  
Yoshiharu Waku ◽  
Narihito Nakagawa ◽  
Kenji Kobayashi ◽  
Shinya Yokoi
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Binary Systems ◽  
Ternary Systems ◽  
Ceramic Composites ◽  
High Temperature Strength ◽  
Air Atmosphere ◽  
Turbine Component ◽  
Near Net Shape ◽  
Plasma Sprayed

Much attention has been paid to unidirectionally solidified ceramic composites as a candidate for a high-temperature structural material. Eutectic composites, known as Melt Growth Composites (MGCs), have recently been developed. The MGCs (Al2O3/YAG, Al2O3/GAP binary and Al2O3/YAG/ZrO2 ternary systems) have a novel microstructure consisting of three-dimensionally continuous and complexly entangled single-crystal Al2O3 and single-crystal oxide compounds (YAG or GAP or YAG and ZrO2). Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, superior oxidation resistance and thermal stability in an air atmosphere at very high temperatures. Manufacturing processes for the MGCs (Al2O3/YAG and Al2O3/GAP binary systems) are being examined under a Japanese national project, scheduled from 2001–2005. The molybdenum mold for near-net-shaped casting of the gas turbine component was fabricated by plasma spraying the molybdenum powders on the copper model. Near-net-shape casting of MGCs is being examined under the NEDO project using the plasma sprayed mold and a new Bridgman-type furnace.

scholarly journals A New Design Methodology for High Temperature Structural Components Made of Continuous Fibre Ceramic Composites Exhibiting Thermally Induced Anisotropic Damage

2002 ◽  
Vol 11 (5) ◽  
pp. 096369350201100
Author(s):  
D.E. Vlachos ◽  
Y.Z. Pappas ◽  
Marco Innocenti ◽  
V. Kostopoulos
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Design Methodology ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Industrial Applications ◽  
Structural Components ◽  
Data Set ◽  
Continuous Fibre ◽  
Oxide Composites

Continuous Fibre Ceramic (Matrix) Composites (CFCCs) have found during the last decade numerous of industrial applications in a variety of technological areas, where structural components are subjected to high temperature combined with significant mechanical loading. The present work deals with the application of an innovative design methodology for the development of an industrial gas turbine combustor chamber made of oxide/oxide composite materials. Oxide/oxide composites offer high-temperature structural stability without the need of any kind of oxidation protection and thus permit the increase of working temperature of the gas turbine, increasing the efficiency of the system and decreasing NOx emissions. Since, oxide/oxide composites degrade their structural properties as a function of the operating temperature (for temperature higher than 1000°C) and the exposure time, an incremental approach has been introduced as a structural design methodology for the combustion chamber, where each increment represents a thermal exposure stage. The data set required for the application of the present design approach, was obtained through an extensive material characterization program based on the measurement of the anisotropic properties of oxide/oxide composites using ultrasonic techniques.

High Temperature Characteristics of Unidirectionally Solidified Eutectic Ceramic Composites and some Potential Applications

2010 ◽  
Vol 638-642 ◽  
pp. 997-1002 ◽  
Author(s):  
Yoshiharu Waku ◽  
Hideyuki Yasuda
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Binary Systems ◽  
Ceramic Composites ◽  
High Temperature Strength ◽  
Experimental Basis ◽  
X Ray ◽  
Air Atmosphere ◽  
Potential Applications ◽  
Very High

We have recently developed ceramic eutectics, which are named Melt Growth Composites (MGCs). The binary MGCs (Al2O3/YAG and Al2O3/GAP binary systems) have a novel microstructure, in which continuous networks of single-crystal Al2O3 phases and single-crystal oxide compounds (YAG or GAP) interpenetrate without grain boundaries. To characterize the entangled structure of the typical MGCs, the X-ray computerized tomography (micro X-ray CT) was performed at a synchrotron radiation facility Spring8. The micro X-ray CT showed that the Al2O3 and the GAP are entangled with each other. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, superior oxidation resistance and thermal stability in the air atmosphere at very high temperatures. To achieve higher thermal efficiency for gas turbine systems, MGC bowed stacking nozzle vanes have been fabricated on an experimental basis.

A Potential Oxide/Oxide Ceramic Matrix Composite for Gas Turbine Applications

2003 ◽  
Author(s):  
Ju¨rgen Go¨ring ◽  
Bernd Kanka ◽  
Martin Schmu¨cker ◽  
Hartmut Schneider
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Ceramic Matrix Composite ◽  
Turbine Engines ◽  
Oxide Ceramic ◽  
Alumino Silicate ◽  
Application Limit ◽  
Oxide Composites ◽  
Highly Porous

WHIPOX® (Wound Highly Porous Oxide CMCs) are oxide/oxide composites which are composed of highly porous alumino silicate or alumina matrices and of alumino silicate (Nextel 720, 3M) or alumina (Nextel 610, 3M) fibers. The materials are fabricated by a computer-controlled winding technique, developed at DLR. After eventual forming and joining steps, the green prepegs are pressureless sintered in air at 1300°C. The high temperature behavior of the CMCs is mainly controlled by the thermo-mechanical properties of the oxide fibers. For long-term use (>10,000 h) an application limit for the composite of about 1100°C is expected. It can, however, be improved by external thermal barrier coatings up to a maximum surface temperature of 1300°C. Gas burner tests show that the composites are extremely resistant against thermal fatigue. Therefore it is a material with a high potential for the use under the long-term high temperature conditions of gas turbine engines.

scholarly journals Oxide/Oxide Ceramic Matrix Composites in Gas Turbine Combustors

1998 ◽  
Author(s):  
Anthony G. Razzell ◽  
Ludovic Molliex ◽  
Magnus Holmquist ◽  
Olivier Sudre
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Room Temperature ◽  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Model Material ◽  
Oxide Ceramic ◽  
Potential Candidate ◽  
High Temperature Stability ◽  
Ceramic Tiles

Gas turbine combustor concepts designed to give improved control of NOx emissions require the usage of hot uncooled walls. The main material properties needed in this application include mechanical and chemical stability at temperatures in excess of 1400°C for long times (>10 000 hours). Composites made from single crystal oxide fibre reinforced oxide with a compatible high temperature stable weak oxide interphase are potential candidate materials to meet these requirements. Alumina was chosen as a model material, unidirectional and 2D composites were processed and a suitable weak zirconia interphase was designed. The process was scaled-up to make production of larger panels and components possible. Mechanical testing was carried out at room temperature to characterise the performance of the material in the as produced and thermally aged condition. Room temperature mechanical properties compared well with other current ceramic composites and excellent high temperature stability was demonstrated. The applicability of the composite as a material for uncooled combustor walls is to be further assessed by evaluation in a combustor test rig. Results from computational fluid dynamics and finite element calculations as well as results from combustor rig tests of monolithic and composite ceramic tiles will be presented.

High Temperature Characteristics of Unidirectionally Solidified Al2O3/GAP Eutectic Composites with a Novel Microstructure

2012 ◽  
Vol 706-709 ◽  
pp. 246-251 ◽  
Author(s):  
Yoshiharu Waku ◽  
Hideki Ohtsubo ◽  
Narihito Nakagawa ◽  
Hideyuki Yasuda
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Single Crystal ◽  
Ceramic Composites ◽  
Chain Structure ◽  
High Temperature Strength ◽  
Temperature Characteristics ◽  
Air Atmosphere ◽  
Very High ◽  
Thermal Stability Of

Much attention has been paid to unidirectionally solidified ceramic composites as candidates for high-temperature structural materials. We have recently developed potential ceramic eutectics, which are named Melt Growth Composites (MGC). The Al2O3/GAP(GdAlO3) binary MGC has a novel microstructure, in which continuous networks of single-crystal Al2O3 phases and single-crystal GAP phases interpenetrate without grain boundaries. Chain structure in the Al2O3/GAP binary system is formed due to the frequent branching of both phases resulted in the entangled structure. Therefore, the Al2O3/GAP binary MGC has excellent high-temperature characteristics in the air atmosphere at very high temperatures. In the paper, high temperature strength, thermal stability of microstructure and strength, and fracture toughness of the Al2O3/GAP binary MGC are reported.

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