Woven ceramic composites

In the last 10 years, significant advances in fibrous monolithic ceramics have been achieved. A variety of materials in the form of either oxide or nonoxide ceramic for cell and cell boundary have been investigated [1], As a result of these efforts, FMs are now commercially available from the ACR company [28], These FMs are fabricated by a coextrusion process. In addition, the green fiber composite can then be wound, woven, or braided into the shape of the desired component. The applications of these FMs involve solid hot gas containment tubes, rocket nozzles, body armor plates, and so forth. Such commercialization of FMs itself proves that these ceramic composites are the most promising structural components at elevated temperatures. 

Chung, G. Y. and Benjamin, J.M., Modeling of chemical vapor infiltration for ceramic composites reinforced with layered, woven fabrics , J. Am. Ceram. Soc., 74, 746 (1991). 

Effect of increasing AT on stress-displacement curves of Nicalon /SiC (CVI) - solid line corresponds to unshocked sample (reprinted from Wang et al. 1996, Thermal shock behaviour of two-dimensional woven fiber-reinforced ceramic composites, ... 

Colomban, P., Bruneton, E., Lagrange, J.L., Mouchon, E., Sol-gel mullite matrix-SiC and -mullite 2D woven fabrics composites with or without zirconia containing interphase. Elaboration and properties, J. Eur. Ceram. Soc., 16, 301, 1996. 

Mouchon, E., and Colomban, P., Oxide ceramic matrix-oxide fibers woven fabric composites exhibiting dissipative fracture behavior. Composites, 26, 175, 1995. 

Most CMCs are reinforced with continuous, multifilament tow ceramic fibers. Fiber tows typically consist of 500 to 1,000 filaments, with a diameter of 10 to 15 pm (0.40 to 0.59 mils) each. These fiber tows are flexible, easy to handle, and can be woven into fabrics and used to fabricate complexshaped composites. Monofilament fibers have also been used to reinforce ceramic composites, but they have several disadvantages. For example, monofilaments (espeeially singleerystal fibers) are expensive, and their large diameter (> 75pm [3.0 mils]) limits their minimum bend radius, whieh ean make fabricating complex-shaped composites difficult. This chapter, therefore, focuses on small diameter, multifilament eeramie fibers. 

Creep deformation in 2-D ceramic composites is a complex phenomenon with deformation possible in the matrix, the woven fabric, the fibers, and the interface layers. Analysis of the data and of the fracture surfaces in these aeep tests does not clearly indicate what... 

R. John, D. J. Buchanan, and L. P. Zawada, Notch-sensitivity of a woven oxide/oxide ceramic matrix composite, in Mechanical, Thermal and Environmental Testing and Performance of Ceramic Composites and... 

E. Mouchon, P. Colomban, Oxide Ceramic Matrix/Oxide Fiber Woven Fabric Composites Exhibiting Dissipative Fracture Behavior, Compo.sites, 26,175-182 (1995). 

K.J. LaRochelle, Tensile Stress Rupture Behavior of a Woven Ceramic Matrix Composite in Humid Environments at Intermediate Temperature, Ph.D. Dissertation, Air Force Institute of Technology (March 2005) Advisor S. Mall. 

Fibrous Composites. These composites consist of fibers in a matrix. The fibers may be short or discontinuous and randomly arranged continuous filaments arranged parallel to each other in the form of woven rovings (coUections of bundles of continuous filaments) or braided (8). In the case of chopped strand mat the random arrangement is planar. In whisker (needle-shaped crystals or filaments of carbon and ceramics) reinforced materials the arrangement is usually three-dimensional and the resulting composites are macroscopically homogeneous. 

Fiber-Matrix Composites. As shown in Figure 1.75, there are two main classifications of FMCs those with continuous fiber reinforcement and those with discontinuous fiber reinforcement. Continuous-flber-reinforced composites are made from fiber rovings (bundles of twisted filaments) that have been woven into two-dimensional sheets resembling a cloth fabric. These sheets can be cut and formed to a desired shape, or preform, that is then incorporated into a composite matrix, typically a thermosetting resin such as epoxy. Metallic, ceramic, and polymeric fibers of specific compositions can all be produced in continuous fashions, and the properties of the... 

Kastritseas, C., Smith, P.A., Yeomans, J.A. (2004b), Damage characterisation of thermally-shocked woven fibre-reinforced ceramic matrix composites , Proceedings of the 11th European Conference in Composite Materials (ECCM-11), Rhodes, Greece, Vol. 2. 

Webb, J.E., Singh, R.N., Lowden, R.A. (1996), Thermal shock damage in a two-dimensional woven-fiber-reinforced-CVI SiC-matrix composite , /. Am. Ceram. Soc., 79(11), 2857-2864. 

FIGURE 12.12 Examples of FGM CMCs (left) the combination of NLM Nicalon SiC fiber reinforced zirconia (in white) and mullite (in black) matrices (right) a Nasicon matrix reinforced with mullite (Nextel) and SiC (NLMTM) fibers (see the sketch). (Reprinted from Colomban, R, Process for fabricating a ceramic matrix composite incorporating woven fibers and materials with different compositions and properties in the same composite, Mater. TechnoL, 10, 89, 1995. With permission.)... 

Colomban, P, Process for fabricating a ceramic matrix composite incorporating woven fibers and materials with different compositions and properties in the same composite, Mater. TechnoL, 10, 89, 1995. 

Cermets, which are mixtures of ceramic and metal powders, heat treated and compressed. (4) Fabrics, e.g., woven combinations of wool or cotton and a synthetic fiber. (5) Filled composites in which a bonding material, i.e., linseed oil, resin, or asphalt, is loaded with a filler in the form of flakes or small particles examples are linoleum, glass flake-plastic mixtures for battery cases, and asphalt-gravel road-surfacing mixtures. 

E. Tani, K. Shobu, and K. Kishi, Two-dimensional-woven-carbon-fiber-reinforced Silicon Carbide/Carbon Matrix Composites Produced by Reaction Bonding, J. Am. Ceram. Soc., 82 [5] 1355-57(1999). 

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