Characterization of Ceramic Components Exposed in Industrial Gas Turbines

2001 ◽  
Author(s):  
M. K. Ferber ◽  
H.-T. Lin
Keyword(s):  
Gas Turbines ◽  
Field Tests ◽  
Biaxial Test ◽  
Silica Layer ◽  
X Ray Diffraction ◽  
Surface Strength ◽  
Ceramic Components ◽  
Industrial Gas Turbines ◽  
The Stability

Abstract This paper provides a review of recent studies undertaken to examine the mechanical and thermal stability of silicon nitride ceramic components that are currently being considered for use in gas turbine applications. Specific components examined included a bowed ceramic nozzle evaluated in an engine test stand, ceramic vanes exposed in two field tests, and an air-cooled vane that is currently under development. Scanning electron microscopy was used to elucidate the changes in the microstructures arising from the environmental effects. The recession of the airfoils resulting from the volatilization of the normally protective silica layer was also measured. The stability of the intergranular phases was evaluated using x-ray diffraction. The surface strength was measured using a miniature biaxial test specimen, which was prepared by diamond core drilling.

Degradation of Silicon Nitrides in High Pressure, Moisture Rich Environments

2000 ◽  
Author(s):  
M. K. Ferber ◽  
H. T. Lin ◽  
V. Parthasarathy ◽  
R. A. Wenglarz
Keyword(s):  
Biaxial Test ◽  
Silica Layer ◽  
X Ray Diffraction ◽  
Surface Strength ◽  
Silicon Nitride Ceramic ◽  
Average Temperature ◽  
Total Exposure Time ◽  
The Stability ◽  
Industrial Gas Turbine ◽  
Thermal Stability Of

This paper provides a review of a recent study undertaken to examine the mechanical and thermal stability of silicon nitride ceramic nozzles exposed in an industrial gas turbine. The average temperature and pressure of gas entering the vanes were approximately 1066°C and 8.9 atm, respectively. The total exposure time was 815 h including a 22 h shakedown test. Scanning electron microscopy was used to elucidate the changes in the microstructures arising from the oxidation process. The recession of the airfoils arising from the volatilization of the normally protective silica layer was also measured. The stability of the intergranular phases was evaluated using x-ray diffraction. The surface strength was measured using a miniature biaxial test specimen which was prepared by diamond core drilling.

Evaluation of Mechanical Reliability of Silicon Nitride Vanes After Field Tests in an Industrial Gas Turbine

2002 ◽  
Author(s):  
H.-T. Lin ◽  
M. K. Ferber ◽  
W. Westphal ◽  
F. Macri
Keyword(s):  
Silicon Nitride ◽  
Gas Turbine ◽  
Field Tests ◽  
Coordinate Measuring Machine ◽  
Biaxial Test ◽  
Silica Layer ◽  
Secondary Phases ◽  
Surface Strength ◽  
Measuring Machine ◽  
Industrial Gas Turbine

This paper provides a review of recent studies undertaken to examine the mechanical and thermal stability of silicon nitride ceramic vanes with and without an oxide-based environmental barrier coating (EBC) after field tests in an industrial gas turbine. Two commercially available silicon nitride vanes (i.e., AS800 and SN282) were evaluated, where the AS800 vanes had an EBC and the SN282 vanes did not. The average temperature and pressure of gas impinging upon the vanes were approximately 1066°C and 8.9 atm, respectively. Both silicon nitride vanes were subjected to exposure time up to 1818h. Scanning electron microscopy was used to provide an insight into the changes in the microstructures of silicon nitrides and EBC arising from the environmental effects. The recession of the airfoils resulting from the volatilization of the normally protective silica layer, and /or EBC, was also measured using a coordinate measuring machine. The long-term chemical as well as structural stability of the secondary phases as well as EBC were characterized using x-ray diffraction. The surface strength of exposed airfoils was evaluated using a miniature biaxial test specimen, which was prepared by a diamond core drilling.

scholarly journals Material Characterization of Candidate Silicon Based Ceramics for Stationary Gas Turbine Applications

1995 ◽  
Author(s):  
Vijay M. Parthasarathy ◽  
Jeffrey R. Price ◽  
William D. Brentnall ◽  
George Graves ◽  
Steven Goodrich
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fatigue Testing ◽  
Composite Ceramics ◽  
Test Bed ◽  
Ceramic Components ◽  
Industrial Gas Turbines ◽  
Improved Performance ◽  
Silicon Based

The Ceramic Stationary Gas Turbine (CSGT) Program is evaluating the potential of using monolithic and composite ceramics in the hot section of industrial gas turbines. Solar Turbine’s Centaur 50 engine is being used as the test bed for ceramic components. The first stage blade, first stage nozzle and the combustor have been selected to develop designs with retrofit potential, which will result in improved performance and lowered emissions. As part of this DOE sponsored initiative a design and life prediction database under relevant conditions is being generated. This paper covers experiments conducted to date on the evaluation of monolithic silicon based ceramics. Mechanical property characterizations have included dynamic fatigue testing of tensile as well as flexural specimens at the temperatures representative of the blade root, the blade airfoil and the nozzle airfoil. Data from subcomponent testing of blade attachment concepts are also included.

scholarly journals Síntese, caracterização e estabilidade de nanopartículas de magnetita

2021 ◽  
Vol 3 (4) ◽  
pp. 2738-2749
Author(s):  
Monise Cristina Ribeiro Casanova Coltro ◽  
Warde Antonieta da Fonseca-Zang ◽  
Joachim Werner Zang ◽  
Danilo César Silva e Sousa
Keyword(s):  
New Technology ◽  
X Ray Diffraction ◽  
Synthesis Of Nanoparticles ◽  
Research Areas ◽  
Magnetite Fe3o4 ◽  
Mineral Substance ◽  
Abundant Element ◽  
The Stability ◽  
Average Size

Nanopartículas de ferro são muito utilizadas em diversas áreas de pesquisa. O elemento químico ferro (Fe), sendo o quarto elemento mais abundante na crosta terrestre, e a substância mineral magnetita, com propriedade magnética, apresentam aplicações nas áreas industrial, ambiental, biomédica e de novas tecnologias. Este trabalho apresenta processo de síntese de nanopartículas partindo-se de sais precursores, bem como a caracterização dos produtos e as rotas para estabilizá-los. Os sais químicos precursores utilizados foram o cloreto férrico (FeCl3) e o sulfato ferroso (FeSO4) na proporção de 2:1, sob agitação por ultrassom e pH ácido. Para formação do precipitado de nanopartículas usou-se solução aquosa de hidróxido de sódio (NaOH) de pH 12. A difratometria de raio-X, mostra a presença de magnetita (Fe3O4) indicada pelos picos característicos de difração em graus 2Ө = 18° (largo), 31° (fino), 36° (bem definido), 43,4°, 45°, 53,6°, 57,7°, 63,3°. A microscopia eletrônica de transmissão mostra a morfologia dos produtos da síntese. Fatores que influenciam a estabilidade das partículas são agitação, o ajuste de pH, condições de secagem. O tamanho médio das nanopartículas de magnetitas é de aproximadamente 15 nm.   Iron nanoparticles are widely used in several research areas. The chemical element iron (Fe), being the fourth most abundant element in the earth's crust, and the mineral substance magnetite, with magnetic properties, have applications in industrial, environmental, biomedical, and new technology areas. This work presents the process of synthesis of nanoparticles starting from precursor salts, as well as the characterization of the products and the routes to stabilize them. The precursor chemical salts were ferric chloride (FeCl3) and ferrous sulfate (FeSO4) in a 2:1 ratio, under ultrasound agitation and acidic pH. For the nanoparticles growth was applied aqueous solution of sodium hydroxide (NaOH) at pH 12. X-ray diffraction shows the presence of magnetite (Fe3O4) indicated by characteristic diffraction peaks in degrees 2Ө = 18° (wide), 31° (fine), 36° (well defined), 43.4°, 45°, 53.6°, 57.7°, 63.3°. Scanning electron microscopy shows the morphology of the synthesis products. Factors that influence the stability of the particles are agitation, the pH adjustment, and the conditions of drying. The average size of the magnetite nanoparticles is approximately 15 nm.

Environmental Characterization of Monolithic Ceramics for Gas Turbine Applications

2005 ◽  
Vol 287 ◽  
pp. 367-380 ◽  
Author(s):  
Mattison K. Ferber ◽  
Hua Tay Lin
Keyword(s):  
Silicon Nitride ◽  
Gas Turbines ◽  
High Performance ◽  
Field Tests ◽  
The United States ◽  
Simple Method ◽  
Ceramic Components ◽  
Carbide Ceramics ◽  
Monolithic Ceramics ◽  
Silicon Carbide Ceramics

Over the last 30 years, a number of programs in Russia, Europe, Japan, and the United States have sought to introduce monolithic ceramic components into gas turbines with the goals of increasing efficiency and lowering emissions. High performance silicon nitride and silicon carbide ceramics typically have been leading candidates for use in these applications. Recent field tests involving silicon nitride vanes and blades have shown that these materials can experience significant recession due to the loss of the normally protective silica scale. This paper first summarizes key findings from these field tests and then describes a relatively simple method for evaluating environmental effects in a laboratory environment.

Synthesis and characterization of the pentazolate anion cyclo-N5ˉ in (N5)6(H3O)3(NH4)4Cl

Science ◽  
2017 ◽  
Vol 355 (6323) ◽  
pp. 374-376 ◽  
Author(s):  
Chong Zhang ◽  
Chengguo Sun ◽  
Bingcheng Hu ◽  
Chuanming Yu ◽  
Ming Lu
Keyword(s):  
Thermal Analysis ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Decomposition Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Onset Decomposition Temperature ◽  
The Stability

Pentazole (HN5), an unstable molecular ring comprising five nitrogen atoms, has been of great interest to researchers for the better part of a century. We report the synthesis and characterization of the pentazolate anion stabilized in a (N5)6(H3O)3(NH4)4Cl salt. The anion was generated by direct cleavage of the C–N bond in a multisubstituted arylpentazole using m-chloroperbenzoic acid and ferrous bisglycinate. The structure was confirmed by single-crystal x-ray diffraction analysis, which highlighted stabilization of the cyclo-N5ˉ ring by chloride, ammonium, and hydronium. Thermal analysis indicated the stability of the salt below 117°C on the basis of thermogravimetry-measured onset decomposition temperature.

The Study and Characterization of a Novel Structure of 1,3,5-Benzenetricarboxylic Acid

2013 ◽  
Vol 830 ◽  
pp. 202-206
Author(s):  
Hai Yan Tan ◽  
Cheng Liu ◽  
Jin Ping Wu
Keyword(s):  
Relevant Information ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Novel Structure ◽  
Ft Ir ◽  
Benzenetricarboxylic Acid ◽  
The Stability ◽  
Lamella Structure

A novel ten-interpenetrating structure of 1,3,5-benzenetricarboxylic acid was grown under solvothemal condition after heated it 16 hours. It was characterized by FT-IR, HNMR, X-ray diffraction, HRTEM. HRTEM obtain the relevant information of structural morphologies. The result of HRTEM showsed this material owned special lamella structure. X-ray diffraction showed the crystal of the new structure is of monoclinic system, space groupP1 with a=26.5039(17), b=16.4121(17),c=26.550(2)Å,α=90.00, β=91.533(2), γ=90.00, V=11544.4(17)Å3, Z=8, Dc=1.451g/cm3,μ=0.126mm-1,F(000)=5184, R=0.0891 and w (R)=0.1819 for 11318 observed reflection with I>2(I),hydrogen bond contributed to the stability of the structure. The fluorescence spectra indicated that the title compound had two stronger emission peak at 346nm and 400nm. Keywords:1, 3, 5-benzenetricarboxylic acid; novel structure; ten-interpenetrating

scholarly journals Microstructure Characterization of Welds in X5CrNiCuNb16-4 Steel in Overaged Condition

2019 ◽  
Vol 19 (1) ◽  
pp. 57-69
Author(s):  
A. Ziewiec ◽  
A. Zielińska-Lipiec ◽  
J. Kowalska ◽  
K. Ziewiec
Keyword(s):  
Electron Microscopy ◽  
Aging Time ◽  
Energy Dispersive Spectrometry ◽  
Solution Treatment ◽  
X Ray Diffraction ◽  
Density Distributions ◽  
Transmission Electron ◽  
Steel Welds ◽  
The Stability

AbstractThe paper presents the results of the investigation of microstructure of the welded X5CrNiCuNb16-4 (17-4PH) steel after solution treatment and aging at 620°C for different periods. The microstructure and the phase composition of the steel was investigated using light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and the X-ray diffraction (XRD). Hardness was measured for samples aged at different times. Density distributions of Cu precipitates were established. The investigation has shown that the microstructure of the X5CrNiCuNb16-4 steel welds after aging at 620 ° C consists of tempered martensite, fine Cu precipitates and austenite. It was observed that the size of the Cu precipitates increases with increasing the aging time, what affects the decrease of hardness. Simultaneously, the quantity of reversed austenite increases with increase of aging time. It was revealed that enrichment of the austenite in Ni, Cu and C affects the increase of Ms, but this factor does not determine the stability of austenite.

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