Local Structural Damage Evaluation of a C/C–SiC Ceramic Matrix Composite

AbstractCeramic matrix composites (CMCs) are structural materials, which have useful properties that combine high strength at high temperatures with moderate toughness. Carbon fibers within a matrix of carbon and silicon carbide, called C/C–SiC, are a particular class of CMC noted for their high oxidation resistance. Here we use a combination of four-point bending and X-ray radiography, to study the mechanical failure of C/C-SiC CMCs. Correlating X-ray radiographic and load/displacement curve data reveals that the fiber bundles act to slow down crack propagation during four-point bending tests. We attribute this to the fact that strain energy is expended in breaking these fibers and in pulling fiber bundles out of the surrounding matrix material. In addition, we find that the local distribution and concentration of SiC plays an important role in reducing the toughness of the material.

Download Full-text

Thermal Diffusivity Imaging of Ceramic Composites

Volume 2: Combustion and Fuels; Oil and Gas Applications; Cycle Innovations; Heat Transfer; Electric Power; Industrial and Cogeneration; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; IGTI Scholar Award ◽

10.1115/93-gt-043 ◽

1993 ◽

Author(s):

K. Elliott Cramer ◽

William P. Winfree ◽

Edward R. Generazio ◽

Ramakrishna Bhatt ◽

Dennis S. Fox ◽

...

Keyword(s):

High Temperature ◽

Thermal Diffusivity ◽

Silicon Nitride ◽

Matrix Material ◽

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Ceramic Composites ◽

Fiber Direction ◽

Large Area

Strong, tough, high temperature ceramic matrix composites are currently being developed for application in advanced heat engines. One of the most promising of these new materials is a SiC fiber-reinforced silicon nitride ceramic matrix composite (SiCf/Si3N4). The interfacial shear strength in such composites is dependant on the integrity of the fiber’s carbon coating at the fiber-matrix interface. The integrity of the carbon rich interface can be significantly reduced if the carbon is oxidized. Since the thermal diffusivity of the fiber is greater than that of the matrix material, the removal of carbon increases the contact resistance at the interface reducing the thermal diffusivity of the composite. Therefore thermal diffusivity images can be used to characterize the progression of carbon depletion and degradation of the composite. A new thermal imaging technique has been developed to provide rapid large area measurements of the thermal diffusivity perpendicular to the fiber direction in these composites. Results of diffusivity measurements will be presented for a series of SiCf/Si3N4 (reaction bonded silicon nitride) composite samples heat-treated under various conditions. Additionally, the ability of this technique to characterize damage in both ceramic and other high temperature composites will be shown.

Download Full-text

Failure Evaluation of a SiC/SiC Ceramic Matrix Composite During In-Situ Loading Using Micro X-ray Computed Tomography

Microscopy and Microanalysis ◽

10.1017/s1431927619000187 ◽

2019 ◽

Vol 25 (3) ◽

pp. 583-591 ◽

Cited By ~ 2

Author(s):

John Thornton ◽

Benedicta D. Arhatari ◽

Mitchell Sesso ◽

Chris Wood ◽

Matthew Zonneveldt ◽

...

Keyword(s):

Computed Tomography ◽

Silicon Carbide ◽

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Nitride Phase ◽

X Ray ◽

Pull Out ◽

Computed Tomography Images ◽

X Ray Computed

AbstractIn this study, we have examined ceramic matrix composites with silicon carbide fibers in a melt-infiltrated silicon carbide matrix (SiC/SiC). We subjected samples to tensile loads while collecting micro X-ray computed tomography images. The results showed the expected crack slowing mechanisms and lower resistance to crack propagation where the fibers ran parallel and perpendicular to the applied load respectively. Cracking was shown to initiate not only from the surface but also from silicon inclusions. Post heat-treated samples showed longer fiber pull-out than the pristine samples, which was incompatible with previously proposed mechanisms. Evidence for oxidation was identified and new mechanisms based on oxidation or an oxidation assisted boron nitride phase transformation was therefore proposed to explain the long pull-out. The role of oxidation emphasizes the necessity of applying oxidation resistant coatings on SiC/SiC.

Download Full-text

Macromodel of interfacial transition layer in ceramic matrix composites

MATEC Web of Conferences ◽

10.1051/matecconf/201814302003 ◽

2018 ◽

Vol 143 ◽

pp. 02003 ◽

Cited By ~ 1

Author(s):

Andrey Stolboushkin ◽

Vadim Syromyasov ◽

Vladimir Vereschagin ◽

Oksana Fomina

Keyword(s):

Transition Layer ◽

Raw Materials ◽

Matrix Material ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

New Mineral ◽

Layer By Layer ◽

Matrix Composites ◽

X Ray ◽

The Core

The purpose of the study is to create a macromodel of interfacial transition layer in ceramic matrix composites. Chemical and mineralogical compositions were investigated by means of X-ray fluorescence analysis and X-ray diffractometry, ceramic and technological properties of raw materials were defined using standard test methods for argillaceous raw materials. Phase composition and structure of ceramic specimens were studied using a complex of modern physico-chemical analysis methods. The layer-by-layer model of shell-core transition in ceramic matrix material was suggested. Boundary conditions for obtaining specimens were defined in terms of number of layers, thickness of such layers and pitch of core-to-shell material ratio. Forced air supply was organized while burning for directed heat and mass transfer inside the specimens. Mineral composition of layers was defined for ceramic specimens with the core of iron ore waste and the shell of clay. The study enabled to determine dependences between qualitative and semi-quantitative variation of new mineral formations content in transitional layers of a composite, which is the evidence of interaction between the core and the shell products while burning a ceramic matrix material.

Download Full-text

Modeling of the Transition Layer in Ceramic Matrix Composites from Coal Wastes and Clay

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.299.37 ◽

2020 ◽

Vol 299 ◽

pp. 37-42

Author(s):

O.A. Fomina ◽

Andrey Yu. Stolboushkin

Keyword(s):

Transition Layer ◽

Raw Materials ◽

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Coal Waste ◽

Matrix Composites ◽

Carbonaceous Particles ◽

The Core ◽

Coal Wastes

A model of the transition layer between the shell and the core of a ceramic matrix composite from coal waste and clay has been developed. The chemical, granulometric and mineral compositions of the beneficiation of carbonaceous mudstones and clay were studied. The technological and ceramic properties of raw materials for the samples manufacturing were determined. The method of manufacturing multilayer ceramic samples from coal waste, clay and their mixture is given. The number of transition layers in the contact zone between the clay shell and the core from coal wastes is determined. The deformation and swelling phenomena of model samples from coal wastes, clay, and their mixtures were revealed at the firing temperature of more than 1000 °C. The formation of a reducing ambient in the center of the sample with insufficient air flow is shown. The influence of the carbonaceous particles amount and the ferrous form iron oxide in the coal wastes on the processes of expansion of multilayer samples during firing has been established.

Download Full-text

Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.483197 ◽

2000 ◽

Vol 122 (2) ◽

pp. 212-218 ◽

Cited By ~ 17

Author(s):

Karren L. More ◽

Peter F. Tortorelli ◽

Mattison K. Ferber ◽

Larry R. Walker ◽

James R. Keiser ◽

...

Keyword(s):

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Surface Damage ◽

Operating Conditions ◽

Matrix Composites ◽

Long Term Stability ◽

Recession Rates ◽

Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15 percent steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions. [S0742-4795(00)02402-9]

Download Full-text

Ceramic Matrix Composite Materials for Engine Exhaust Systems on Next-Generation Vertical Lift Vehicles

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4040011 ◽

2018 ◽

Vol 140 (10) ◽

Cited By ~ 1

Author(s):

Michael J. Walock ◽

Vann Heng ◽

Andy Nieto ◽

Anindya Ghoshal ◽

Muthuvel Murugan ◽

...

Keyword(s):

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Thermal Exposure ◽

Gas Flows ◽

Matrix Composites ◽

Engine Exhaust ◽

Ir Camera ◽

Before And After ◽

Ceramic Components

Future gas turbine engines will operate at significantly higher temperatures (∼1800 °C) than current engines (∼1400 °C) for improved efficiency and power density. As a result, the current set of metallic components (titanium-based and nickel-based superalloys) will be replaced with ceramics and ceramic matrix composites (CMCs). These materials can survive the higher operating temperatures of future engines at significant weight savings over the current metallic components, i.e., advanced ceramic components will facilitate more powerful engines. While oxide-based CMCs may not be suitable candidates for hot-section components, they may be suitable for structural and/or exhaust components. However, a more thorough understanding of the performance under relevant environment of these materials is needed. To this end, this work investigates the high-temperature durability of a family of oxide–oxide CMCs (Ox–Ox CMCs) under an engine-relevant environment. Flat Ox–Ox CMC panels were cyclically exposed to temperatures up to 1150 °C, within 240 m/s (∼0.3 M) gas flows and hot sand impingement. Front and backside surface temperatures were monitored by a single-wavelength (SW) pyrometer and thermocouple, respectively. In addition, an infrared (IR) camera was used to evaluate the damage evolution of the samples during testing. Flash thermography nondestructive evaluation (NDE) was used to elucidate defects present before and after thermal exposure.

Download Full-text

Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

Mathematical Problems in Engineering ◽

10.1155/2019/8175689 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Hye-gyu Kim ◽

Wooseok Ji ◽

Nam Choon Cho ◽

Jong Kyoo Park

Keyword(s):

Optimization Algorithm ◽

Fracture Behavior ◽

Ceramic Matrix Composite ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Shear Loading ◽

Matrix Composites ◽

Specific Loading ◽

Smeared Crack Approach ◽

Smeared Crack

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions.

Download Full-text

A Study on the Mechanical Properties of Polymer-Ceramic Composite Using Injection Moulding

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.159.35 ◽

2012 ◽

Vol 159 ◽

pp. 35-40 ◽

Cited By ~ 3

Author(s):

Nasuha Sa'ude ◽

Mustaffa Ibrahim ◽

Ibrahim Raman

Keyword(s):

Matrix Composite ◽

Palm Oil ◽

Ceramic Composite ◽

Matrix Material ◽

Ceramic Matrix Composite ◽

Ceramic Matrix ◽

Molding Machine ◽

Weight Percentage ◽

Major Development ◽

Oil Fly Ash

This paper presents the development of a new polymer-ceramic composite material for use in injection molding machine. The material consists of palm oil fly ash (POFA) in a high density polyethylene (HDPE) powder. In this study, the effect of POFA was investigated as a filler material in polymer-ceramic matrix composite and HDPE was chosen as a matrix material. The detailed formulations of mixing ratio with various combinations of the new polymer-ceramic composite are investigated experimentally. Based on the result obtained, it was found that, the weight percentage increment of POFA filler affected the flexural and hardness strength. This work represents a major development in recycling of waste material from palm oil empty fruit bunch out of the refinery to produce polymer/ceramic matrix composite.

Download Full-text

Study of Preforms of Quartzite for Production of Ceramic Matrix Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.591-593.430 ◽

2008 ◽

Vol 591-593 ◽

pp. 430-435

Author(s):

Adriana Scoton Antonio Chinelatto ◽

R. Justus ◽

Adilson Luiz Chinelatto ◽

F.M.C.N. Nadal ◽

E.A.T. Berg

Keyword(s):

Squeeze Casting ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Matrix Composites ◽

X Ray Diffraction ◽

Flexure Strength ◽

Pressure Infiltration ◽

X Ray ◽

Infiltration Technique ◽

Sufficient Strength

The ceramic matrix composites (CMCs) can be fabricated by the pressure infiltration technique. In this work it was studied porous preforms of quartzite that were infiltrated with aluminum liquid. For to produce the more resistant preforms of quartzite, it was additioned different quantities of bentonite (5 and 10%) and the preforms were firing at 1100°C and 1200°C. For the composites production, the melted aluminum was introduced into preforms under a pressure of 7 MPa. The characterizations of the composites were made by X-ray diffraction, scanning electron microscopy, and flexure strength. All the preforms studied presented sufficient strength for support the pressing during the process of squeeze casting. The results of X-ray diffraction of composites showed the presence of alumina, silicon and aluminum and fully interpenetration aluminum-siliconalumina composites were obtained by infiltration.

Download Full-text