Lockheed Martin Corporation

Lockheed Missiles & Space Company, Inc.

Robert D Yasukawa

Jerome Paul Wittenauer

Venecia M Grobelny

Kenneth W Benner

James Perry Woolley

Sarah D Reeves

Loretta Jane Cordrey

An article used for thermal protection includes a base structure having at least one surface. The base structure is made of a ceramic oxide material. A silicide coating is formed on the at least one surface of the base structure. The coating comprises a refractory metal and silicon, which together form a silicide. The coating is at least partially diffused into the base structure at the at least one surface.

Durable refractory ceramic coating

A method is provided for preparing a low density porous rigid fused-fiber matrix having a density of between about 3.5 and 5.5 pounds/cubic foot and a free volume of between about 90-98 volume percent for use as a cell-culture substrate or implant material, or in chromatographic separation of blood cells. The method is carried out by forming a slurry containing (I) silica, alumina or silica and alumina fibers having thicknesses between about 0.5 and 20 .mu.m and lengths between about 1 and 10 mm, and having a fiber:liquid weight ratio of between about 1:25 to 1:70, (ii) a thickening agent to give the slurry a viscosity between about 1,000 and 25,000 centipoise, (iii) boron nitride particles between about 2-12 percent by weight of the total fiber weight, and (iv) a dispersing agent when the slurry contains silica fibers, allowing the slurry to settle in a mold to produce a fiber block, drying the fiber block, and heating the dried fiber block to at least about 2200.degree. F. for a period sufficient to cause the fibers to form the fused-fiber matrix. Graphite or polymer filler elements may be provided in the mold prior to settling of the slurry to form strands or spacers in the fiber block that vaporize during heating to produce channels or plates separated by voids. Two or more slurries can be formed having different fiber thicknesses, densities or compositions to produce a matrix having a discontinuous gradient of density or layers of different compositions.

Method of preparing a low-density porous fused-fiber matrix

A rigid acoustic insulator panel for use as a sound insulator is disclosed. The panel is composed of a rigid matrix formed of randomly oriented, fused silica fibers having fiber diameters predominantly in the range between 0.5 and 2 .mu.m. The matrix has a three-dimensionally continuous network of open, intercommunicating voids, and a density of between about 2 and 6 lb/ft.sup.3. In one embodiment, the panel has greater flow resistance characteristics, progressing from a sound-absorbing side of the matrix to the opposite panel side. Also disclosed is a method of preparing the panel.

Acoustical ceramic panel and method

Low density fused fibrous ceramic composites are prepared from amorphous silica and/or alumina fibers with 2 to 12% boron nitride by weight of fibers, used as a fluxing agent to reduce the melting temperature of the fibers and allow the fibers to fuse at their intersections creating a three dimensional rigid matrix. The matrix is useful as a cell-culture substrate, as an implant material, and for chromatographic separation of blood cells.

Porous matrix and method of its production

An acoustic structure for use as a sound insulator in a jet engine is disclosed. The structure, which is carried in a sound-absorbing compartment of the engine, includes a framework and an acoustical insulation material disposed within the framework. The material is composed of a rigid matrix of randomly oriented, fused silica fibers having fiber diameters predominantly in the range 2-8 .mu.m, a three-dimensionally continuous network of open, intercommunicating voids, a flow resistivity between about 10-200K rayls/m, and a density of between about 2 and 8 lb/ft3. Also disclosed are a clad acoustical structure for sound attenuation in a jet engine, where operational temperatures exceed current jet engine designs, and a method of attenuating jet engine noise.

Growing community of inventors

San Jose, CA, United States of America

Robert D Yasukawa