Evaluation of Ceramic Rotor Strength by Cold and Hot Spin Tests

1996 ◽  
Vol 118 (1) ◽  
pp. 191-197
Author(s):  
M. Watanabe ◽  
H. Ogita
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Maximum Stress ◽  
Bending Strength ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Turbine Rotor ◽  
Matrix Composites ◽  
Burst Test ◽  
High Temperature Condition

Presently in Japan 100 kW ceramic gas turbines (CGT) for automobiles are under development, parts of which include a turbine rotor, scrolls, a combustor, and other parts made of ceramics and ceramic matrix composites. The rotor is designed to rotate at 110,000 rpm, equal to the maximum stress of 300 MPa, and to be exposed to temperatures up to 1350°C. Initially, the strength of ceramic rotors was evaluated by a burst test using a cold spin tester. The burst picture was observed and compared with the 4pt bending strength of the ceramic test specimens. Next, the strength of the rotors was tested by a hot spin test and the burst result of the rotor was evaluated. A high-speed camera was used to observe the rotor at the instant of burst under a high-temperature condition. Applying the result of the cold and hot spin tests, ceramics for turbine rotor were selected and the shape of the rotor was designed.

Evaluation of Ceramic Rotor Strength by Cold and Hot Spin Tests

1994 ◽  
Author(s):  
Makoto Watanabe ◽  
Hiroshi Ogita
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Bending Strength ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
High Heat ◽  
Turbine Rotor ◽  
Matrix Composites ◽  
Automotive Engine

Presently in Japan 100 kW ceramic gas turbines (CGT) for automobiles are under development, parts of which include a turbine rotor, scrolls, a combustor, and other parts made of ceramics and ceramic matrix composites. The rotor is designed to rotate at 110,000 rpm, equal to the maximum stress of 300 MPa and to be exposed to temperatures up to 1350°C. Initially, the strength of ceramic rotors was evaluated by a burst test using a cold spin tester. The burst picture was observed and compared with the 4pt bending strength of the ceramic test specimens. Next, the strength of the rotors was tested by a hot spin test and the burst result of the rotor was evaluated. A high speed camera was used to observe the rotor at the instant of burst under a high temperature condition. Applying the result of the cold and hot spin tests, ceramics for turbine rotor were selected and the shape of the rotor was designed as a practical automotive engine began in 1990 as a project of the Petroleum Energy Center with financial support from the Agency of Natural Resources and Energy, the Ministry of International Trade and Industry. In order to obtain a 40% or higher thermal efficiency, the automotive gas turbine requires the use of a turbine rotor, combustor, shroud and other engine parts that can withstand high temperatures of 1200°C to 1500°C. In addition, since their resistance to thermal stress and impact are primary considerations, it is necessary to develop high heat-resistant materials (ceramic type materials). Fig. 1 shows a sectional model of the automotive ceramic gas turbine now under development. Under this project, a monolithic ceramic rotor was first evaluated as a turbine rotor. Ceramic matrix composites were then studied.

scholarly journals The effect of microstructural features on the mechanical properties of LZSA glass-ceramic matrix composites

Cerâmica ◽  
2013 ◽  
Vol 59 (351) ◽  
pp. 351-359 ◽  
Author(s):  
F. M. Bertan ◽  
A. P. Novaes de Oliveira ◽  
O. R. K. Montedo ◽  
D. Hotza ◽  
C. R. Rambo
Keyword(s):  
Glass Ceramic ◽  
Bending Strength ◽  
Chemical Properties ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Linear Shrinkage ◽  
Matrix Composites ◽  
Particulate Reinforced ◽  
And Chemical Properties

This work reports on the characterization of ZrSiO4 particulate-reinforced Li2O-ZrO2-SiO2-Al2O3 (LZSA) glass-ceramic matrix composites. The typical physical/mechanical and chemical properties of the glass batches and the composites were measured. A composition with 60 wt.% ZrSiO4 was preliminarily selected because it demonstrated the highest values of bending strength (190 MPa) and deep abrasion resistance (51 mm³). To this same composition was given a 7 wt.% bentonite addition in order to obtain plasticity behavior suitable for extrusion. The sintered samples (1150 ºC for 10 min) presented a thermal linear shrinkage of 14% and bending strength values of 220 MPa.

scholarly journals Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines

2011 ◽  
Author(s):  
Gregory Corman ◽  
Krishan Luthra ◽  
Jill Jonkowski ◽  
Joseph Mavec ◽  
Paul Bakke ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Industrial Gas Turbines

Influence of Compaction Pressure on Density, Bending Strength, and Microstructures of Al2O3-SiC-ZrO2 Ceramic Matrix Composites with Nb2O5 Additives

2018 ◽  
Vol 923 ◽  
pp. 61-65
Author(s):  
Dewi Lestari Natalia ◽  
Risly Wijanarko ◽  
Irene Angela ◽  
Bondan Tiara Sofyan
Keyword(s):  
Bending Strength ◽  
Compaction Pressure ◽  
Density Measurement ◽  
Ceramic Matrix Composites ◽  
High Hardness ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sintering Process ◽  
Product Density ◽  
Microstructure Observation

Ceramic matrix composites (CMCs) are known to have high hardness, temperature and corrosion resistance, while being comparatively lightweight. One of many external factors that influence the mechanical properties of CMC is the compaction pressure given during fabrication process. Generally, greater amount of applied compaction pressure will result in improved final product density and bending strength. In this research, a type of CMCs was fabricated using Al2O3, SiC, and ZrO2 powder mixed with Nb2O5 additive of 81Al2O3-10SiC-5ZrO2-4Nb2O5 wt. % composition. Fabrication was done through mixing, compacting, and sintering process. Compaction was performed at 257, 308, and 359 MPa and finished with sintering process at 1400 °C for 4 h. Final samples were characterized by density measurement, 3-point bending strength testing, XRD for phase investigation, and microstructure observation using SEM-EDS. Results showing that samples with 308 MPa compaction pressure possessed the highest density and bending strength of 3.29 gr/cm3 and 14.91 MPa, respectively. These numbers however, declined on samples with higher compaction pressure of 359 MPa due to the formation of porosities caused by entrapped gas that failed to exit the sample of which compaction pressure was considered to be overwhelmingly high.

Effect of Microporosity on Damage Initiation in Ceramic Matrix Composites

2019 ◽  
Author(s):  
Suhasini Gururaja ◽  
Abhilash Nagaraja
Keyword(s):  
Gas Turbines ◽  
Ceramic Matrix Composites ◽  
Local Stress ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Damage Initiation ◽  
The Matrix ◽  
Homogenization Approach ◽  
Matrix Porosity ◽  
Monolithic Ceramics

Abstract Ceramic matrix composites (CMC) are a subclass of composite materials consisting of reinforced ceramics. They retain the advantages of ceramics such as lower density and better refractory properties but exhibit better damage tolerance compared to monolithic ceramics. This combination of properties make CMCs an ideal candidate for use in high temperature sections of gas turbines. However, modeling the damage mechanisms in CMCs is complex due to the heterogeneous microstructure and the presence of processing induced defects such as matrix porosity. The effect of matrix pore location and orientation on damage initiation in CMCs is of interest in the present work. CMCs fabricated by various fabrication processes exhibit matrix pores at different length scales. Microporosities exist within fiber bundles in CMCs have a significant effect on microscale damage initiation and forms the focus of the current study. In a previous work by the authors, a two step numerical homogenization approach has been developed to model statistical distribution of matrix pores and to obtain the effective mechanical properties of CMCs in the presence of matrix porosity. A variation of that approach has been adopted to model matrix pores and investigate the severity of pores with respect to their location and orientation. CMC microstructure at the microscale has been modeled as a repeating unit cell (RUC) consisting of fiber, interphase and matrix. Ellipsoidal pores are modeled in the matrix with pore distance from the interphase-matrix interface and pore orientation with respect to the loading direction as parameters. Periodic boundary conditions (PBCs) are specified on the RUC by means of constraint equations. The effect of the pore on the local stress fields and its contribution to matrix damage is studied.

Fabrication of TiAl/B4C Composites from an Al-Ti-B4C System Reinforced by TiC, TiB2 In Situ

2009 ◽  
Vol 79-82 ◽  
pp. 477-480 ◽  
Author(s):  
Li Hua Dong ◽  
Wei Ke Zhang ◽  
Jian Li ◽  
Yan Sheng Yin
Keyword(s):  
Bending Strength ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
High Energy ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hot Pressing Sintering ◽  
Different Content

Near full dense B4C ceramic matrix composites were fabricated from Ti-Al-B4C system by combining high energy milling with hot pressing sintering. The effect of different content of Ti-Al on the mechanical properties and microstructure of the as-prepared composites was investigated. A TiAl/B4C composite, whose typical bending strength and fracture toughness are 437.3 MPa and 4.85 MPa•m1/2, respectively, was made. The sintering mechanism and reinforcement mechanism were discussed with the assistant of X-Ray diffraction and electron microscopy.

INTRODUCTION TO C3HARME PROJECT

2021 ◽  
Author(s):  
LUCA ZOLI ◽  
DILETTA SCITI
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Thermal Protection ◽  
Weight Ratio ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Thermal Protection Systems ◽  
Protection Systems ◽  
Ultra High Temperature

High-speed aviation brings many challenges, one being the materials used ensure the aircraft and rockets travelling at hypersonic speed arrive at their destination safely. Control surfaces and thermal protection systems for vehicles flying at Mach 5 or above must withstand extremely hot temperatures and intense mechanical vibrations at launch, during cruising and re-entry into the Earth’s atmosphere. UHTCMCs (Ultra-High Temperature Ceramic Matrix Composites) belong to a new subclass of ceramic matrix composites (CMCs) with superior properties in terms of structural and chemical stability at elevated temperature and erosion/ablation resistance keeping excellent strength-to-weight ratio, thermal shock resistance and adequate damage tolerance. They are the latest potential candidates for thermal protection systems (TPSs), able to outperform bulk ultra-high temperature ceramics (UHTCs). C3HARME is a 4-years EU funded program involving 12 European partners from 6 countries focused on the design, fabrication and testing of UHTCMCs for nearzero erosion nozzles and near-zero ablation TPS tiles. C3harme will look at different technologies coming from the science of bulk ceramics and CMCs and combine them to find out new approaches for their manufacturing. Novel theoretical models and testing methodologies are necessary to characterize properly these materials. This talk will summarize some of the findings and advances of the program, with special emphasis on the innovative approaches that we have implemented.

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