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Process for the preparation of a fibre-reinforced carbon composite
Loszewski, R.C. (AVCO Corporation, Providence, RI, USA) US Pat 4 898 778 (6 February 1990) A high strength silicon carbide monofilament consists of a core with a stoichiometric bulk layer of silicon carbide deposited on the core. The average grain size of the bulk layer increases from the interface of the core and the bulk layer to a single peak of maximum grain size and then reduces again to a second average grain size at the exterior surface of the bulk layer. The maximum grain size is less than 200 nm and the overall average grain size is between 90 and 100 nm. Metal matrix composite with coated reinforcing preform Gallernault, W.M.T. and Gabryel, C.M. (Alcan International Limited, Montreal, Canada) US Pat 4 899 800 (13 February 1990) A preform comprising bonded strontiumcoated reinforcing fibres is infiltrated under pressure with a melt of aluminium-silicon alloy containing a modifying amount of strontium. The whole is allowed to solidify by cooling. Process for using sludge from geothermal brine to make concrete and concrete composition Whitescarver, O.D., Kwan, J.T., Chan, M.K. and Hoyer, D.P. (Union Oil Company of California, Los Angeles, CA, USA) US Pat 4 900360 (13 February 1990) A layer of siliceous sludge precipitated from silica-rich geothermal brine and a layer of Portland-type cement are deposited onto ground soil. These layers are mixed together, activating media added, compacted and then allowed to cure to form a structural concrete material. Method of installing a cathodic protection system for a steel-reinforced concrete structure Bennett, J.E., Pohto, G.R. and Mitchell, T.A. (Eltech Systems Corporation, Boca Raton, FL, USA) US Pat 4 900 410 (13 February 1990) At least one elongated valve metal current distributor is laid onto the surface of the concrete structure. A mesh sheet of valve metal which has an electrochemically active coating is unrolled over and fixed to the distributor and the concrete surface. The mesh and the distributor are then embedded in an ion-conductive overlay. Method of producing isotropically reinforced net-shape microcomposites Witzke, H. and Kear, B.H. (Exxon Research and Engineering Company, Florham Park, NJ, USA) US Pat 4 900 483 (13 February 1990) One or more hydrocarbons that will catalytically decompose to form a filamentary carbon are brought into contact with a metallic catalyst consisting of a solid solution of nickel and copper to produce multidirectional carbon fibres in a mould held at a temperature sufficient to produce filamentary carbon without causing pyrolytic deposition of carbon. A matrix material is then introduced to the mould, converted to a solid and the whole removed from the mould. Reservoir feed method making ceramic composite structures and structures made thereby Newkirk, M.S., Lesher, H.D., Dwivedi,
R.K. and Kantner, R.C. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 4 900 699 (13 February 1990) A permeable mass of filler material and a source of parent metal are placed relative to each other such that the molten metal will be drawn through the filler, producing an oxidation reaction product round the filler in the process. The whole is heated to a temperature above the melting point of the metal but below the melting point of the oxidation reaction product. The metal supply is insufficient to result in the filler material being completed embedded in reaction product and thus a second reservoir of molten parent metal is used to at least partially replenish the first source during the reaction process. Method for connection composite pipes Hata, R. (Sumitomo Electric Industries Ltd, Osaka, Japan) US Pat 4 901 415 (20 February 1990) A method is described of connecting two composite pipes that each comprise a lead pipe inside, and in contact with, an aluminium pipe. The ends of the aluminium pipes are cut off to give two exposed ends of lead pipe. One of these is increased in diameter so that it can receive the other. The two lead pipes are connected together and a glass tape reinforced with an epoxy resin is wound round the connected pipe ends to form a reinforcing layer. Method for making fibre reinforced glass matrix composite article having selectively orientated fibre reinforcement Jarmon, D.C. (United Technologies Corporation, Hartford, CT, USA) US Pat 4 902 326 (20 February 1990) A fibre preform with the reinforcing fibres disposed in selected orientations is impregnated with a colloidal suspension or inorganic particles suspended in a continuous medium. The whole is cooled down to or below the freezing point of the continuous medium so that the inorganic particles are precipitated to form a rigid fibre preform which is subsequently dried before being impregnated with a heated glass matrix material. Finally, the whole is once again cooled to form the composite article. Process for the preparation of a fibrereinforced carbon composite Okura, A., Cho, T., Nakagawa, T., Gomi, S. and Ueda, T. (Across Co Ltd, Japan) US Pat 4 902 453 (20 February 1990) A multiplicity of inorganic reinforcing fibres are continuously passed through a bed of mixed powder including a finely divided carbonaceous binder pitch and a finely divided coke. The powder is taken up by the interstices between the fibres; they are then assembled into a tow around which a thermoplastic resin sleeve is extruded. The whole is carbonized by heating to produce a fibrereinforced carbon composite. Method for manufacturing a porous material or a composite sintered product comprising zirconium oxide and a carbide Wada, T., Adachi, S. and Mihara, T. (Matsushita Electric Industrial Co Ltd, Japan) US Pat4 902 457 (20 February 1990) A powder of an alloy of zirconium and aluminium, yttrium or magnesium is mixed with a metal oxide powder and a carbon powder. The mixture is shaped and portion of
the shaped mixture is ignited in an atmosphere that is inert to a combustion reaction of the mixture so that reaction starts in and proceeds through the shaped body. During the reaction the zirconium alloy powder is converted to zirconia solid solution and the metal oxide is converted to metal carbide giving a composite body comprised of zirconia and a metal carbide. Process for preparing carbon fibres of high strength Imai, K., Sumoto, M., Nakamura, H. and Miyahara, N. (Nikkiso Co Ltd, Tokyo, Japan) US Pat 4 902 762 (20 February 1990) A polymeric solution is formed by homopolymerizing acrylonitrile or copolymerizing at least 85 weight % acrylonitrile with other vinyl polymers in a concentrated zinc chloride aqueous solution, pH of not more than 2, with impurity levels of basic salts and 0.01-5 weight % in excess of the equivalent amount of basic salts of hydrogen chloride. The solution is spun to form precursor filaments and then carbonized to give high strength carbon fibres. The process avoids aglutination during forming and the hydrogen chloride reduces the amide groups in the fibres and increases the strength of the carbon fibres formed. Bonding of FRP parts Beecher, J.F. and Cocain, H.W. (GenCorp Inc, Fairlawn, OH, USA) US Pat 4 904 328 (27 February 1990) At least two thermoset FRP parts are treated for a period between 0.1 and 10 seconds with shortwave UV radiation at between 0.051 0 W c m 2 to remove about 0.1-20nm material to provide clean substrate surfaces. At least one of these surfaces is coated with an epoxy-based or a polyurethane-based adhesive or with combinations of these adhesives; the two surfaces are joined and the adhesive is cured and heat-treated to bond the two parts together. Process for preparing self-supporting bodies and products made thereby White, D.R. and Claar, T.D. (Lanxidc Technology Company, LP, Newark, DE, USA) US Pat 4 904 446 (27 February 1990) A parent metal is heated in a substantially inert atmosphere to a temperature above its melting point. The molten metal is brought into contact with a permeable mass containing boron nitride. The temperature is maintained so that the permeable mass is infiltrated by the metal and the boron nitride and the metal react to form at least one boroncontaining compound. The process is continued until a self-supporting body is produced. Microwave irradiation of composites Worner, H.K. (Wollongong Uniadvice Limited, New South Wales, Australia) US Pat 4 906 290 (6 March 1990) Particulate ores or concentrate are intimately admixed with one of finely comminuted past, brown coal and lignite and finely comminuted plant matter to form a compact composite. The compact is compressed and irradiated with microwaves such that the compact dries and the carbon-containing material is charred. Further irradiation to a temperature in excess of 300°C is used to initiate reduction reactions in the composite as a precursor step to smelting.
COMPOSITES. NOVEMBER 1991
479
R.K. and Kantner, R.C. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 4 900 699 (13 February 1990) A permeable mass of filler material and a source of parent metal are placed relative to each other such that the molten metal will be drawn through the filler, producing an oxidation reaction product round the filler in the process. The whole is heated to a temperature above the melting point of the metal but below the melting point of the oxidation reaction product. The metal supply is insufficient to result in the filler material being completed embedded in reaction product and thus a second reservoir of molten parent metal is used to at least partially replenish the first source during the reaction process. Method for connection composite pipes Hata, R. (Sumitomo Electric Industries Ltd, Osaka, Japan) US Pat 4 901 415 (20 February 1990) A method is described of connecting two composite pipes that each comprise a lead pipe inside, and in contact with, an aluminium pipe. The ends of the aluminium pipes are cut off to give two exposed ends of lead pipe. One of these is increased in diameter so that it can receive the other. The two lead pipes are connected together and a glass tape reinforced with an epoxy resin is wound round the connected pipe ends to form a reinforcing layer. Method for making fibre reinforced glass matrix composite article having selectively orientated fibre reinforcement Jarmon, D.C. (United Technologies Corporation, Hartford, CT, USA) US Pat 4 902 326 (20 February 1990) A fibre preform with the reinforcing fibres disposed in selected orientations is impregnated with a colloidal suspension or inorganic particles suspended in a continuous medium. The whole is cooled down to or below the freezing point of the continuous medium so that the inorganic particles are precipitated to form a rigid fibre preform which is subsequently dried before being impregnated with a heated glass matrix material. Finally, the whole is once again cooled to form the composite article. Process for the preparation of a fibrereinforced carbon composite Okura, A., Cho, T., Nakagawa, T., Gomi, S. and Ueda, T. (Across Co Ltd, Japan) US Pat 4 902 453 (20 February 1990) A multiplicity of inorganic reinforcing fibres are continuously passed through a bed of mixed powder including a finely divided carbonaceous binder pitch and a finely divided coke. The powder is taken up by the interstices between the fibres; they are then assembled into a tow around which a thermoplastic resin sleeve is extruded. The whole is carbonized by heating to produce a fibrereinforced carbon composite. Method for manufacturing a porous material or a composite sintered product comprising zirconium oxide and a carbide Wada, T., Adachi, S. and Mihara, T. (Matsushita Electric Industrial Co Ltd, Japan) US Pat4 902 457 (20 February 1990) A powder of an alloy of zirconium and aluminium, yttrium or magnesium is mixed with a metal oxide powder and a carbon powder. The mixture is shaped and portion of
the shaped mixture is ignited in an atmosphere that is inert to a combustion reaction of the mixture so that reaction starts in and proceeds through the shaped body. During the reaction the zirconium alloy powder is converted to zirconia solid solution and the metal oxide is converted to metal carbide giving a composite body comprised of zirconia and a metal carbide. Process for preparing carbon fibres of high strength Imai, K., Sumoto, M., Nakamura, H. and Miyahara, N. (Nikkiso Co Ltd, Tokyo, Japan) US Pat 4 902 762 (20 February 1990) A polymeric solution is formed by homopolymerizing acrylonitrile or copolymerizing at least 85 weight % acrylonitrile with other vinyl polymers in a concentrated zinc chloride aqueous solution, pH of not more than 2, with impurity levels of basic salts and 0.01-5 weight % in excess of the equivalent amount of basic salts of hydrogen chloride. The solution is spun to form precursor filaments and then carbonized to give high strength carbon fibres. The process avoids aglutination during forming and the hydrogen chloride reduces the amide groups in the fibres and increases the strength of the carbon fibres formed. Bonding of FRP parts Beecher, J.F. and Cocain, H.W. (GenCorp Inc, Fairlawn, OH, USA) US Pat 4 904 328 (27 February 1990) At least two thermoset FRP parts are treated for a period between 0.1 and 10 seconds with shortwave UV radiation at between 0.051 0 W c m 2 to remove about 0.1-20nm material to provide clean substrate surfaces. At least one of these surfaces is coated with an epoxy-based or a polyurethane-based adhesive or with combinations of these adhesives; the two surfaces are joined and the adhesive is cured and heat-treated to bond the two parts together. Process for preparing self-supporting bodies and products made thereby White, D.R. and Claar, T.D. (Lanxidc Technology Company, LP, Newark, DE, USA) US Pat 4 904 446 (27 February 1990) A parent metal is heated in a substantially inert atmosphere to a temperature above its melting point. The molten metal is brought into contact with a permeable mass containing boron nitride. The temperature is maintained so that the permeable mass is infiltrated by the metal and the boron nitride and the metal react to form at least one boroncontaining compound. The process is continued until a self-supporting body is produced. Microwave irradiation of composites Worner, H.K. (Wollongong Uniadvice Limited, New South Wales, Australia) US Pat 4 906 290 (6 March 1990) Particulate ores or concentrate are intimately admixed with one of finely comminuted past, brown coal and lignite and finely comminuted plant matter to form a compact composite. The compact is compressed and irradiated with microwaves such that the compact dries and the carbon-containing material is charred. Further irradiation to a temperature in excess of 300°C is used to initiate reduction reactions in the composite as a precursor step to smelting.
COMPOSITES. NOVEMBER 1991
479