Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer material(s) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body.

Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer materials) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body.

Abstract: The present invention relates to the use of a gating means in combination with a spontaneous infiltration process to produce a metal matrix composite body. Particularly, a permeable mass of filler material or a preform is spontaneously infiltrated by molten matrix metal to form a metal matrix composite body. A gating means is provided which controls or limits the areal contact between molten matrix metal and the filler material or preform. The use of a gating means provides for control of the amount of matrix metal which can contact the preform or filler material, which may result in less machining of a formed metal matrix composite body compared with a similar metal matrix composite body made without a gating mean. Moreover, the use of a gating means ameliorates the tendency of a formed metal matrix composite body to warp due to the contact between the formed composite body and matrix metal carcass.

Abstract: Coated ceramic filler materials comprised of ceramic particles, fibers, whiskers, etc. having at least two substantially continuous coatings thereon are provided. The coatings are selected so that the interfacial shear strength between the ceramic filler material and the first coating, between coatings, or between the outer coating and the surrounding matrix material, are not equal so as to permit debonding and pull-our when fracture occurs. The resultant, multi-coated ceramic filler materials may be employed to provide composites, especially ceramic matrix composites, with increased fracture toughness. The ceramic filler materials are designed to be particularly compatible with ceramic matrices formed by directed oxidation of precursor metals, but such ceramic filler materials are also adaptable for use in many other composite material systems.In a preferred embodiment, the coatings are applied to the ceramic fiber plies or preforms by CVD.

Abstract: The present invention relates to a novel method for forming metal matrix composite bodies and novel products produced by the method. Particularly, a permeable mass of filler material or a preform is provided which has included therein at least some matrix metal powder. Moreover, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with the filler material or preform, at least at some point during the process, which permits molten matrix metal, upon contact with the filler material or preform, to spontaneously infiltrate the filler material or preform. The presence of powdered matrix metal in the preform or filler material reduces the relative volume fraction of filler material to matrix metal.