Ceramics, advanced composites

Infiltration (67) provides a unique means of fabricating ceramic composites. A ceramic compact is partially sintered to produce a porous body that is subsequently infiltrated with a low viscosity ceramic precursor solution. Advanced ceramic matrix composites such as alumina dispersed in zirconia [1314-23-4] Zr02, can be fabricated using this technique. Complete infiltration produces a homogeneous composite partial infiltration produces a surface modified ceramic composite. 

Advanced materials systems based on polymers, ceramics, and composites are constmcted by assembling components to create stmctures whose properties and performance are determined by the form, orientation, and complexity of the composite stmcture. The properties of these assemblages are determined not by the sum of weighted averages of the components but rather by synergistic effects in intercoimected phases. For this reason, the study of fabrication of hierarchical assemblages of materials, as well as the study of mechanisms for repairing defects in assembled stmctures, must be supported by fundamental research. 

U.S. Congress, Office of Technology Assessment. New Structural Materials Technologies Opportunities for the Use of Advanced Ceramics and Composites—A Technical Memorandum (OTA-TM-E-32). Washington, D.C. U.S. Government Printing Office, 1986. 

MATERIALS SCIENCE IS A CRITICAL TECHNOLOGY for America. In 1987 and again in 1990, the U.S. Department of Commerce included advanced materials such as ceramics, polymers, advanced composites, and superconductors in a short list (1) of very important emerging technologies. The world market based on these advanced materials was estimated conservatively at 600 million by the year 2000. 

Sprenkle V, Kim JY, Meinhardt K, Lu C, Chick L, Canfield N et al. Sulfur poisoning studies on the Delphi-Battelle SECA program. Presented at The 31st International Cocoa Beach Conference and Exposition on Advanced Ceramics and Composites, 2007 Daytona Beach, FL. 

R.N. Singh, High Temperature Seals for Solid Oxide Fuel Cells, 28th International Conference on Advanced Ceramics and Composites, eds., E. Lara-Curzio and M.J. Readey, Cocoa Beach, FL, 25 (3), pp. 299-307 (2004). 

E. Corral, B. Gauntt, and R. Loehman, Controlling Seal Materials Properties for Reliable Seal Performance Using Glass-Ceramic Composites, 30th International Conference on Advanced Ceramics and Composites, Daytona Beach, FI. January 21-26, 2007. 

Composite interfaces, ceramic—matrix composites, 5 558-561 Composite liner, in landfills, 25 877 Composite material coatings, 14 105 Composite materials, 13 533 26 750-785. See also Composites advanced materials in, 1 693 classification by geometry, 26 752-755 classification by matrix material,... 

Lowden, R.A. (1991). In Advanced Composite Materials, Ceramic Trans., 19, American Ceramic Soc. Westerville, OH, p. 619. 

Dieffendorf, R. J. (1985). Comparison of the various new high modulus fibers for reinforcement of advanced composites with polymers, metals and ceramics as matrix, pp. 46-61. In Fitzer, E. ed. Carbon Fibers and Their Composites, Springer-Verlag, New York. 

Despite the emphasis on favorable interactions between the matrix and reinforcement and compound formation between them, it may be beneficial in certain circumstances for the interaction between the two primary constituents to be relatively weak. This is especially true in ceramic-ceramic composites, where both constituents are brittle, and the only way to impart some ductility on the composite is for the interphase to fail gracefully —that is, for the fibers to actually pull out of the matrix in a controlled manner. Optimization of the interphase properties in advanced composites is currently the focus of much research. 

Model particles can also be used to develop processing methods for the fabrication of advanced structural ceramics and composites of high strength (see, e.g., Vignette 1.5). 

Gnsalfe. S.J. "Ceramic-Malrix Composites." Advanced Materials A Pnu-esses. 43 tJanuarv 19901. 

Metals and ceramics (claylike materials) are also used as matrices in advanced composites. In most cases, metal matrix composites consist of aluminum, magnesium, copper, or titanium alloys of these metals or intermetallic compounds, such as TiAl and NiAl. The reinforcement is usually a ceramic material such as boron carbide (B4C), silicon carbide (SiC), aluminum oxide (A1203), aluminum nitride (AlN), or boron nitride (BN). Metals have also been used as reinforcements in metal matrices. For example, the physical characteristics of some types of steel have been improved by the addition of aluminum fibers. The reinforcement is usually added in the form of particles, whiskers, plates, or fibers. 

As discussed previously, ceramic matrix composites were originally developed to overcome the brittleness of monolithic ceramics. Thermal shock, impact and creep resistance can also be improved, making CMCs premium replacement choices for some technical ceramics. Industrial applications such as in automotive gas turbines or advanced cutting tools are already taking advantage of such characteristics. 

Mogensen, M., S.H. Jensen, A. Hauch, I. Chorkendorff, T. Jacobsen (2008), Reversible Solid Oxide Cells , Ceramic Engineering and Science Proceedings, Vol. 28, No. 4, Advances in Solid Oxide Fuel Cells III - A Collection of Papers Presented at the 31st International Conference on Advanced Ceramics and Composites, pp. 91-101. 

Each chapter in the book has been written by an internationally recognized expert in the field of ceramic matrix composites. The chapters are organized to include a substantial review of the fundamentals. The authors have integrated material from a wide range of sources to provide a perspective for their own research contributions. The overview character of the chapters makes this book useful not only to researchers in the ceramics community but also to graduate students in advanced ceramics courses. 

T.-J. Chuang, D. F. Carroll, and S. M. Wiederhom Creep Rupture of a Metal-Ceramic Particulate Composite, Seventh International Conference on Fracture, in Advances in Fracture Research, Vol. 4, eds., K. Salama, K. Ravi-Chandler, D. M. R. Taplin, and P. Rama Rao, Pergamon Press, New York, NY, 1989, pp. 2965-2976. 

---