Tensile Damage Characterization in Nicalon Fiber Reinforced Ceramic Composites

2006 ◽  
Vol 326-328 ◽  
pp. 1237-1242
Author(s):  
Jeong Guk Kim
Keyword(s):  
Thermal Diffusivity ◽  
Fracture Behavior ◽  
Ceramic Matrix Composites ◽  
Tensile Tests ◽  
Ceramic Composites ◽  
In Situ Monitoring ◽  
Tensile Failure ◽  
Failure Behavior ◽  
Matrix Composites ◽  
Ir Thermography

Tensile failure behavior of ceramic matrix composites (CMCs) was characterized with nondestructive evaluation (NDE) techniques. Prior to the mechanical testing, infrared (IR) thermography was employed to obtain thermal diffusivity maps for CMC specimens. IR thermography also was used for quantitative analyses of the progressive damage and in-situ monitoring of the damage during tensile tests, while ultrasonic (UT) C-scans were used to present defect distributions of the composites. The thermal diffusivity map showed good consistency with ultrasonic C-scan results of CMC specimens. In this investigation, qualitative relationship between UT signatures and thermal diffusivity has been introduced, and the temperature changes of CMC specimens during tensile test have been measured. Moreover, the correlation between NDE results and fracture behavior of CMCs has been presented to understand tension fracture behavior of CMCs.

Multilayered Fiber-Reinforced Oxide Composites Produced by Lamination of Thermoplastic Prepregs

2014 ◽  
Vol 89 ◽  
pp. 145-150 ◽  
Author(s):  
Paula O. Guglielmi ◽  
Diego Blaese ◽  
Murilo Hablitzel ◽  
Gabriel Nunes ◽  
Victor R. Lauth ◽  
...  
Keyword(s):  
Bending Strength ◽  
Mechanical Performance ◽  
Hierarchical Structures ◽  
Ceramic Matrix Composites ◽  
Organic Matrix ◽  
Ceramic Composites ◽  
Processing Route ◽  
Failure Behavior ◽  
Matrix Composites ◽  
Fiber Reinforced

For advanced ceramic composites, affordable manufacturing is still the most essential shortcoming with respect to successful commercial use. This holds particularly for components made out of composites with complex hierarchical structures and high demands of mechanical performance and reliability at the same time, e.g. fiber-reinforced ceramic matrix composites (FRCMCs). Therefore, a new processing route is presented here, which is based on the lamination of thermoplastic prepregs. This route allows not only affordable manufacturing, but also advanced mechanical reliability. Powder metallurgy techniques are combined here with concepts from the prepreg technology in a route consisting of the following steps (a) manufacturing of 2 D prepregs using commercial fiber fabrics which are infiltrated with compounds of ceramic particles embedded in an organic matrix, (b) followed by respective stacking and joining, (c) burn out of the organic matrix and (d) sintering to consolidate the matrix. Composites consisting of a porous Al2O3/ZrO2 matrix, reinforced by 8 layers of NextelTM 610 fiber fabric exhibit a bending strength of ~440 MPa, with graceful failure behavior, e.g. a stepwise stress reduction after peak nominal stress. The fracture of these composites is controlled by a series of interfacial delamination events, which enhance energy dissipation during failure.

Fracture Behavior of Ceramic Matrix Composites during Monotonic and Cyclic Loadings

2007 ◽  
Vol 345-346 ◽  
pp. 649-652 ◽  
Author(s):  
Jeong Guk Kim ◽  
Peter K. Liaw
Keyword(s):  
Fracture Behavior ◽  
Glass Ceramics ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Cyclic Fatigue ◽  
In Situ Monitoring ◽  
Matrix Composites ◽  
Ir Camera ◽  
Temperature Changes ◽  
Ceramics Matrix

The fracture behavior of ceramic matrix composites (CMCs) was investigated using the infrared (IR) thermography nondestructive evaluation (NDE) technique during monotonic and cyclic loadings. The CMCs used for this investigation are continuous Nicalon (silicon carbide fiber) fiber reinforced calsium aluminosilicate (CAS) glass-ceramics matrix composites. During monotonic tension and cyclic fatigue loadings, IR camera was used for in-situ monitoring of temperature evolution, and the temperature changes during testing were measured. Microstructural characterizations using scanning electron microscopy (SEM) were performed to investigate fracture modes and failure mechanisms of Nicalon/CAS samples. In this investigation, the NDE technique and SEM characterization were employed to facilitate a better understanding of damage evolution and progress of Nicalon/CAS composites during monotonic and cyclic loadings.

scholarly journals Investigation of Failure Mechanisms in Ceramic Composites as Potential Railway Brake Disc Materials

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5141
Author(s):  
Jeongguk Kim
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Ceramic Composite ◽  
Failure Mechanisms ◽  
Ceramic Matrix Composites ◽  
Tensile Tests ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Fracture Characteristics ◽  
Ceramic Composite Materials

Ceramic composite materials have been efficiently used for high-temperature structural applications with improved toughness by complementing the shortcomings of monolithic ceramics. In this study, the fracture characteristics and fracture mechanisms of ceramic composite materials were studied. The ceramic composite material used in this study is Nicalon ceramic fiber reinforced ceramic matrix composites. The tensile failure behavior of two types of ceramic composites with different microstructures, namely, plain-weave and cross-ply composites, was studied. Tensile tests were performed on two types of ceramic composite material specimens. Microstructure analysis using SEM was performed to find out the relationship between tensile fracture characteristics and microstructure. It was found that there was a difference in the fracture mechanism according to the characteristics of each microstructure. In this study, the results of tensile tests, failure modes, failure characteristics, and failure mechanisms were analyzed in detail for two fabric structures, namely, plain-weave and cross-ply structures, which are representative of ceramic matrix composites. In order to help understanding of the fracture process and mechanism, the fracture initiation, crack propagation, and fracture mechanism of each composite material are schematically expressed in a two-dimensional figure. Through these results, it is intended to provide useful information for the design of ceramic composite materials based on the mechanistic understanding of the fracture process of ceramic composite materials.

NDE Characterization and Mechanical Behavior in Ceramic Matrix Composites

2006 ◽  
Vol 321-323 ◽  
pp. 946-951 ◽  
Author(s):  
Jeong Guk Kim ◽  
Sung Tae Kwon ◽  
Won Kyung Kim
Keyword(s):  
Mechanical Behavior ◽  
Nondestructive Evaluation ◽  
Tensile Testing ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
In Situ Monitoring ◽  
Matrix Composites ◽  
Ir Camera ◽  
Qualitative Relationship ◽  
Microscopy Characterization

Several nondestructive evaluation (NDE) techniques, including ultrasonic C-scan, X-ray computed tomography (CT), and infrared (IR) thermography, were employed on ceramic matrix composites (CMCs) to illustrate defect information that might effect mechanical behavior and to analyze structural performance of CMCs. Prior to tensile testing, through C-scan and CT analyses results, the qualitative relationship between the relative ultrasonic transmitted amplitude and porosity based on CT was exhibited. An IR camera was used for in-situ monitoring of progressive damages and to determine temperature changes during tensile testing. Moreover, scanning-electron microscopy characterization was used to perform microstructural failure analyses. This paper describes the use of nondestructive evaluation (NDE) techniques to facilitate the understanding of tension behavior of CMCs.

Metal-Reinforced Ceramic Composites for Turbine Vanes

1972 ◽  
Author(s):  
S. A. Bortz
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Metal Fiber ◽  
Turbine Engine ◽  
Turbine Vanes ◽  
The Matrix ◽  
The Relationship ◽  
Structural Matrix

Experiments have been performed which indicate the potential of metal-fiber reinforced-ceramic matrix composites for use as a high temperature structural matrix. The results of this work reveal that metal-fiber reinforced ceramics obey compostie theory, and that after cracks occur in the matrix, a pseudo-ductility can be introduced into the composite. This toughness can be predicted from equations of work required to pull the fibers through the matrix. The relationship between strength, toughness, and crack depths, are dependent on the inter-facial bond between the fibers and matrix as well as fiber diameter and length. Based on the results of these experiments, multicomponent materials with superior resistance to failure from oxidation, thermal shock, and high mechanical stresses in air above 2400 F can be postulated. These materials have potential for use as gas turbine engine vanes.

Study of Interlaminar Fracture Properties of Ceramic Matrix Composites at Room and Elevated Temperatures

2017 ◽  
Author(s):  
Rabih Mansour ◽  
Yogesh P. Singh ◽  
Manigandan Kannan ◽  
Gregory N. Morscher ◽  
Frank Abdi ◽  
...  
Keyword(s):  
Crack Growth ◽  
Cross Sections ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Ceramic Matrix Composites ◽  
In Situ Monitoring ◽  
Matrix Composites ◽  
Interlaminar Stresses ◽  
Fracture Properties ◽  
Interlaminar Fracture

Interlaminar fracture properties play an important role in predicting failure of structural components for CMC materials. In engine applications, components are subject to large thermal gradients which induce interlaminar stresses. One of the main challenges in evaluating interlaminar fracture toughness at room and elevated temperatures is the development of an experimental setup that provides ease for testing and allows for in-situ monitoring of the interlaminar crack growth. Therefore, a wedge-loaded DCB testing method is developed. The method utilize electrical resistance to monitor crack growth and was applied to a woven polymer infiltrated pyrolysis (PIP) SiC/SiNC composite. Post-testing inspection was carried out using optical microscopy of polished cross-sections, showing crack morphology. It was found that crack growth rate at room temperature is double the one at 815 °C for initial tests in this composite system. Estimates of Mode I energy release rate suggests flat R-curve behavior at room temperature in comparison to rising R-curve behavior at 815 °C.

scholarly journals Mechanical Behavior of Fiber-Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment

1993 ◽  
Vol 115 (1) ◽  
pp. 91-102 ◽  
Author(s):  
A. Chulya ◽  
J. P. Gyekenyesi ◽  
R. T. Bhatt
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Matrix Composites ◽  
In Situ Monitoring ◽  
Matrix Cracking ◽  
Test Problems ◽  
Interface Debonding ◽  
Failure Behavior ◽  
Fiber Reinforced ◽  
History Effects ◽  
Pull Out

The mechanical behavior of continuous fiber-reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytic predictions.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
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.

Thermal Diffusivity Imaging of Ceramic Composites

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.

scholarly journals Mechanical Properties and Failure Behavior of 3D-SiCf/SiC Composites with Different Interphases

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Deng-hao Ma ◽  
En-ze Jin ◽  
Jun-ping Li ◽  
Zhen-hua Hou ◽  
Jian Yin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Shear Strength ◽  
Ceramic Matrix Composites ◽  
Failure Behavior ◽  
Matrix Composites ◽  
Static Mechanical ◽  
Sic Composites ◽  
Polymer Infiltration ◽  
Static Mechanical Properties

Continuous silicon carbide fiber-reinforced silicon carbide ceramic matrix composites (SiCf/SiC) are promising as thermal structural materials. In this work, the microstructure and static mechanical properties of 3D-SiCf/SiC with PyC, SiC, and PyC/SiC and without an interface prepared via polymer infiltration and pyrolysis (PIP) were investigated systematically in this paper. The results show that the microstructure and static mechanical properties of SiCf/SiC with an interphase layer were superior to the composites without an interlayer, and the interface debondings are existing in the composite without an interphase, resulting in a weak interface bonding. When the interphase is introduced, the interfacial shear strength is improved, the crack can be deflected, and the fracture energy can be absorbed. Meanwhile, the shear strength of the composites with PyC and PyC/SiC interfaces was 118 MPa and 124 MPa, respectively, and showing little difference in bending properties. This indicates that the sublayer SiC of the PyC/SiC multilayer interface limits the binding state and the plastic deformation of PyC interphase, and it is helpful to improve the mechanical properties of SiCf/SiC.

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