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Fibre-reinforced refractory composites
Pittsburgh, PA, USA) US Pat 5 098 874 (24 March 1992) A slurry ofaluminium oxide, boron oxide and an organic binder suspended in a liquid is infiltrated into a body of ceramic fibres, and the liquid and organic binder are removed. The fibres are coated to produce a stable interface between them and the aluminium borate matrix which is formed by sintering the infiltrated body; the reaction that produces the aluminium borate involves a volume expansion which aids in the removal of porosity.
Method of making ceramic composite bodies incorporating filler material and bodies produced thereby Kuszyk, J.A. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 5 100 837 (31 March 1992) A 55 to 80% dense mass of filler material, which contains 50 to 60 vol% of 54 grit filler, 15 to 25 vol% of 90 grit filler, 10 to 20 vol% of 180 grit filler and 5 to 15 vol% of 500 grit filler, is formed and placed adjacent to a parent metal. The whole is then heated to a temperature above the melting point of the parent metal such that the parent metal oxidizes. The oxidation reaction product is progressively deposited through the filler material to produce a wear resistant ceramic-matrix composite comprising oxidation reaction product, one or more non-oxidized constituents of the parent metal and a high hardness filler. Process for fabricating novel composites based on reinforcement with microfibrillar networks of rigid-rod polymers Farris, R.J. (of Northampton (Leeds), MA, USA), Cohen, Y. (of Haifa, Israel) and DeTeresa, S.J. (of Livermore, CA, USA) US Pat 5 102 601 (7 April 1992) The solvent of a solution of a rigid polymer is replaced with a coagulant which induces microfibrillar formation. Diffusion is used to interpenetrate the microfibrils with a matrix to form a microfibrillar-reinforced composite. Method and apparatus for vacuum bag moulding of composite materials Honka, P.J. (McDonnell Douglas Corporation, St. Louis, MO, USA) US Pat 5 106 658 (21 April 1992) A number of prepregs are laid up on a forming tool and are overlaid with at least one sheet of a non-porous material. This is overlaid with a breather material and the whole is enclosed within an impermeable membrane. The volume within the membrane is evacuated
900
and the resin in the prepregs is outgassed. The prepregs are coalesced; the resin cures after which the composite is removed from the tool.
Method of making ceramic composites Lesher, H.D., Kennedy, C.R., White, D.R. and Urquhart, A.W. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 5 106 789 (21 April 1992) A parent metal and a permeable mass of filler coated with a silicic precursor are placed next to each other. The filler is heated so that silicic precursor dissociates to form a silicon source coating which can act as an intrinsic dopant in the subsequent reactions. The metal is then heated to a temperature above its melting point and is progressively drawn through the filler body, reacting with an oxidant as it progresses, to form a ceramic oxidation reaction product within the filler and thereby the composite body. Method of forming a precracked fibre coating for toughening ceramic fibre-matrix composites Carpenter, H.W. and Bohlen, J.W. (Northrop Corporation, Hawthorne, CA, USA) US Pat 5 110 771 (5 May 1992) A precursor oxidizable coating is deposited on the ceramic fibres. The fibres are then infiltrated with a ceramic matrix to form a composite after which the coating is oxidized, thereby forming multiple microcracks in the coating. Composite preforms and articles and methods for their manufacture Spain, R.G. and DeGrood, S.M. (Airfoil Textron Inc, Lima, OH, USA) USA Pat 5 112 545 (12 May 1992) A preform of reinforcing strands is impregnated with a silicone resin solution and the resin is cured to form the desired shape. After this the shaped preform is heated such that the resin is converted to silica in sufficient quantity to maintain the preform shape during subsequent handling and infiltration of an inorganic matrix material. Method to fabricate titanium aluminide matrix composites Smith Jr, P.R., Revelos, W.C. and Eylon, D. (Secretary of the Air Force, Washington, DC, USA) US Pat 5 118 025 (2 June 1992) Layers of t-stabilized Ti3AI foil, coated on at least one side with a sacrificial quantity of fl stabilizer, are alternated with layers of filaments of silicon carbide, silicon carbidecoated boron, boron carbide-coated boron
COMPOSITES.NUMBER9.1994
and silicon carbide-coated silicon carbide to form a preform. Heat and pressure are used to consolidate the preform into the composite material.
Incorporation of ceramic particles into a copper base matrix to form a composite material Ashok, S. (Olin Corporation, Cheshire, CT, USA) US Pat 5 120 612 (9 June 1992) A molten stream of copper or a copper-based alloy containing a eutectic reactive element which is capable of diffusing into ceramic particles is atomized. Ceramic particles are intro'duced into the atomized stream and the stream is deposited on a moving substrate to form a copper-based alloy containing ceramic particles.
Method of making hybrid composite structures of fibre-reinforced glass and resin matrices Minford, E., Prewo, K.M. and Miller, R.J. (United Technologies Corporation, Hartford, CT, USA) US Pat 5 122 226 (16 June 1992) The surface of a preconsolidated fibre-reinforced glass matrix is pretreated to expose the fibres and a mass of fibre-containing resin is moulded to it such that the exposed fibres are embedded in the resin. The resin is then cured to form a fibre-reinforced composite which is bonded to a fibre-reinforced glass composite. The resulting composite is lightweight and has a localized abrasion resistant and elevated temperature resistant region.
Fibre-reinforced refractory composites Strekert, H.H. and Bujas, R.S. (General Atomics, San Diego, CA, USA) US Pat 5 I33 933 (28 July 1992) A fibrous preform is wetted with an aqueous solution of boric acid or decaborene and is then infiltrated with a fluid-containing precursor that can be pyrolysed to form silicon carbide, silicon nitride or boron nitride. The infiltrated preform is then heated such that the precursor is cured and pyrolysed. The resulting body is infiltrated with a different precursor-containing fluid, the precursor again being pyrolysable to form silicon carbide, silicon nitride or boron nitride. The reinfiltrated body is then heated to cure and pyrolyse the second precursor and to produce a fibre-reinforced refractory composite with good high temperature oxidation resistance.
Method of making ceramic composite bodies incorporating filler material and bodies produced thereby Kuszyk, J.A. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 5 100 837 (31 March 1992) A 55 to 80% dense mass of filler material, which contains 50 to 60 vol% of 54 grit filler, 15 to 25 vol% of 90 grit filler, 10 to 20 vol% of 180 grit filler and 5 to 15 vol% of 500 grit filler, is formed and placed adjacent to a parent metal. The whole is then heated to a temperature above the melting point of the parent metal such that the parent metal oxidizes. The oxidation reaction product is progressively deposited through the filler material to produce a wear resistant ceramic-matrix composite comprising oxidation reaction product, one or more non-oxidized constituents of the parent metal and a high hardness filler. Process for fabricating novel composites based on reinforcement with microfibrillar networks of rigid-rod polymers Farris, R.J. (of Northampton (Leeds), MA, USA), Cohen, Y. (of Haifa, Israel) and DeTeresa, S.J. (of Livermore, CA, USA) US Pat 5 102 601 (7 April 1992) The solvent of a solution of a rigid polymer is replaced with a coagulant which induces microfibrillar formation. Diffusion is used to interpenetrate the microfibrils with a matrix to form a microfibrillar-reinforced composite. Method and apparatus for vacuum bag moulding of composite materials Honka, P.J. (McDonnell Douglas Corporation, St. Louis, MO, USA) US Pat 5 106 658 (21 April 1992) A number of prepregs are laid up on a forming tool and are overlaid with at least one sheet of a non-porous material. This is overlaid with a breather material and the whole is enclosed within an impermeable membrane. The volume within the membrane is evacuated
900
and the resin in the prepregs is outgassed. The prepregs are coalesced; the resin cures after which the composite is removed from the tool.
Method of making ceramic composites Lesher, H.D., Kennedy, C.R., White, D.R. and Urquhart, A.W. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 5 106 789 (21 April 1992) A parent metal and a permeable mass of filler coated with a silicic precursor are placed next to each other. The filler is heated so that silicic precursor dissociates to form a silicon source coating which can act as an intrinsic dopant in the subsequent reactions. The metal is then heated to a temperature above its melting point and is progressively drawn through the filler body, reacting with an oxidant as it progresses, to form a ceramic oxidation reaction product within the filler and thereby the composite body. Method of forming a precracked fibre coating for toughening ceramic fibre-matrix composites Carpenter, H.W. and Bohlen, J.W. (Northrop Corporation, Hawthorne, CA, USA) US Pat 5 110 771 (5 May 1992) A precursor oxidizable coating is deposited on the ceramic fibres. The fibres are then infiltrated with a ceramic matrix to form a composite after which the coating is oxidized, thereby forming multiple microcracks in the coating. Composite preforms and articles and methods for their manufacture Spain, R.G. and DeGrood, S.M. (Airfoil Textron Inc, Lima, OH, USA) USA Pat 5 112 545 (12 May 1992) A preform of reinforcing strands is impregnated with a silicone resin solution and the resin is cured to form the desired shape. After this the shaped preform is heated such that the resin is converted to silica in sufficient quantity to maintain the preform shape during subsequent handling and infiltration of an inorganic matrix material. Method to fabricate titanium aluminide matrix composites Smith Jr, P.R., Revelos, W.C. and Eylon, D. (Secretary of the Air Force, Washington, DC, USA) US Pat 5 118 025 (2 June 1992) Layers of t-stabilized Ti3AI foil, coated on at least one side with a sacrificial quantity of fl stabilizer, are alternated with layers of filaments of silicon carbide, silicon carbidecoated boron, boron carbide-coated boron
COMPOSITES.NUMBER9.1994
and silicon carbide-coated silicon carbide to form a preform. Heat and pressure are used to consolidate the preform into the composite material.
Incorporation of ceramic particles into a copper base matrix to form a composite material Ashok, S. (Olin Corporation, Cheshire, CT, USA) US Pat 5 120 612 (9 June 1992) A molten stream of copper or a copper-based alloy containing a eutectic reactive element which is capable of diffusing into ceramic particles is atomized. Ceramic particles are intro'duced into the atomized stream and the stream is deposited on a moving substrate to form a copper-based alloy containing ceramic particles.
Method of making hybrid composite structures of fibre-reinforced glass and resin matrices Minford, E., Prewo, K.M. and Miller, R.J. (United Technologies Corporation, Hartford, CT, USA) US Pat 5 122 226 (16 June 1992) The surface of a preconsolidated fibre-reinforced glass matrix is pretreated to expose the fibres and a mass of fibre-containing resin is moulded to it such that the exposed fibres are embedded in the resin. The resin is then cured to form a fibre-reinforced composite which is bonded to a fibre-reinforced glass composite. The resulting composite is lightweight and has a localized abrasion resistant and elevated temperature resistant region.
Fibre-reinforced refractory composites Strekert, H.H. and Bujas, R.S. (General Atomics, San Diego, CA, USA) US Pat 5 I33 933 (28 July 1992) A fibrous preform is wetted with an aqueous solution of boric acid or decaborene and is then infiltrated with a fluid-containing precursor that can be pyrolysed to form silicon carbide, silicon nitride or boron nitride. The infiltrated preform is then heated such that the precursor is cured and pyrolysed. The resulting body is infiltrated with a different precursor-containing fluid, the precursor again being pyrolysable to form silicon carbide, silicon nitride or boron nitride. The reinfiltrated body is then heated to cure and pyrolyse the second precursor and to produce a fibre-reinforced refractory composite with good high temperature oxidation resistance.