Composite materials ceramic-matrix composites

There are three types of composite materials Ceramic matrix composites (CMC) consisting of fibers embedded in a ceramic matrix. 

Other Matrix Materials. Advanced materials, eg, stmctural components, in aerospace vehicles also employ ceramics and metals as composite matrices (see Composite materials, ceramic-matrix Metal-matrix composites). 

Those basic matrix selection factors are used as bases for comparing the four principal types of matrix materials, namely polymers, metals, carbons, and ceramics, listed in Table 7-1. Obviously, no single matrix material is best for all selection factors. However, if high temperatures and other extreme environmental conditions are not an issue, polymer-matrix materials are the most suitable constituents, and that is why so many current applications involve polymer matrices. In fact, those applications are the easiest and most straightforward for composite materials. Ceramic-matrix or carbon-matrix materials must be used in high-temperature applications or under severe environmental conditions. Metal-matrix materials are generally more suitable than polymers for moderately high-temperature applications or for modest environmental conditions other than elevated temperature. 

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,... 

Creep resistance -of particulate reinforced composites [COMPOSITE MATERIALS - CERAMIC MATRIX] (Vol7)... 

Graphite fibers [CARBON AND GRAPHITE FIBERS] (Vol 5) [COMPOSITEMATERIALS - SURVEY] (Vol 7) as ceramic composite reinforcements [COMPOSITE MATERIALS - CERAMIC MATRIX] (Vol 7) useofbrominein [BROMINE] (Vol4)... 

Reinforcements. The high modulus, high intrinsic strength, and temperature stabiHty make SiC, in the form of whiskers, platelets, and fibers, a promising candidate reinforcement material for metal, polymer, and ceramic matrix composites (qv). 

Directed Oxidation of a Molten Metal. Directed oxidation of a molten metal or the Lanxide process (45,68,91) involves the reaction of a molten metal with a gaseous oxidant, eg, A1 with O2 in air, to form a porous three-dimensional oxide that grows outward from the metal/ceramic surface. The process proceeds via capillary action as the molten metal wicks into open pore channels in the oxide scale growth. Reinforced ceramic matrix composites can be formed by positioning inert filler materials, eg, fibers, whiskers, and/or particulates, in the path of the oxide scale growth. The resultant composite is comprised of both interconnected metal and ceramic. Typically 5—30 vol % metal remains after processing. The composite product maintains many of the desirable properties of a ceramic however, the presence of the metal serves to increase the fracture toughness of the composite. 

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