having the higher percentage of Zn. Glass fibre reinforced thermoplastic resin compositions Ushiroji, M. and Yoshihara, Y. (Mitsui Petrochemical Industries, Ltd, Tokyo, Japan) US Pat4 912 150 (27March 1990) A glass fibre-reinforced polypropylenepolyamide resin composition. The resin comprises 25-65 weight % of a propyleneethylene copolymer with an ethylene content of 5-30 mole % and 35-75 weight % of polyamide. 10-100 parts of glass fibre, 0.5-5 parts of a grafted polypropylene with an unsaturated carboxylic acid or its derivatives grafted onto it (based on the weight of the copolymer and the polyamide) and 0.02-0.5 weight % of an organic peroxide (based on the weight of the copolymer) are also present. Heat-resistant composite body Tsukada, K. (Ibiden Co Ltd, Ogaki, Japan) US Pat 4 913 738 (3 April 1990) A composite body of silicon carbide is formed from sintered silicon carbide particles with 45-145 parts by weight (compared with 100 parts of silicon carbide) of metallic silicon filling interconnected pores. The silicon carbide particles have an average diameter of 5 lam or less and 60 weight % or more of them have a diameter within + 20% of the average particle diameter. At least some silicon carbide particles are present as bonded, porous, secondary particles with fine pores of diameter less than 3 lam and coarser pores with diameters between 15 and 40 ~tm. High strength high modulus carbon fibres Takai, Y., Takabatake, M., Nakajima, H., Takano, K. and Watanabe, M. (Kashima Oil Company, Tokyo, Japan) US Pat 4 913 889 (3 April 1990) The fibres are derived from mesophase pitch and consist of a plurality of sheets of long arrangements of planes of hexagonal carbon networks. The sheets are highly oriented in the direction of the fibre axis and have a wrinkled layer cross-sectional structure with a radius of curvature of 1.5-20 nm. Modified carbon fibre reinforced cement Sawanobori, T., Noguchi, Y., Sakai, H. and Sone, K. (Mitsubishi Kasei Corporation, Tokyo, Japan) US Pat 4 915 739 (10 April
1990) A reinforced cement is produced by mixing a reinforcing quantity of fibres into a watercurable cement. The fibres are prepared by the impregnating carbon fibres with 50-200 weight % of a thermosetting resin, coating them with 10-200 weight % of a rubber solution or rubber latex, and curing the coated fibres. Reinforcing steel having resistance to salt and capable of preventing deterioration of concrete Shimada, H., Sakakibara, Y. and Waseda, T. (Nippon Steel Corporation, Tokyo, Japan) US Pat 4 915 901 (10 April 1990) A high-purity reinforcing steel is claimed that is capable of retarding the deterioration of concrete even when the salt content of the concrete exceeds 0.5 weight % based on the sand in the concrete. The steel consists of 0.001-1.0 weight % C, not greater than 0.05 weight % Si, 0.01-2.0 weight % Mn, less than 0.015 weight % P, less than 0.005 weight % S, 1.0-5.5 weight % Ni, 0.001-0.5 weight % W,
0.001-0.1 weight % AI with the balance being Fe and incidental impurities. Cement reinforcing fibre Sawanobori, T., Noguchi, Y., Sakai, H. and Sone, K. (Mitsubishi Kasei Corporation, Tokyo, Japan) US Pat 4 916 012 (10 April 1990) A cement reinforcing fibre is formed by impregnating a carbon fibre with 50-200 weight % (relative to the fibre) of thermosetting epoxy resin. The impregnated fibre is coated with 10-200 weight % (relative to the fibre) of a styrene-butadiene rubber latex and the whole is cured. Composites having an intermetallic containing matrix Nagle, D.C., Brupbacher, J.M. and Christodoulou, L. (Martin Marietta Corporation, Bethesda, MD, USA) US Pat 4 916 029 (10 April 1990) A composite material comprises a dispersion of in situ precipitated, second phase boride, carbide, nitride or sulphide particles in an intermetallic-containing matrix selected from the aluminides, silicides and beryllides of Ni, Cu, Ti, Co, Fe, Pt, Au, Ag, Nb, Ta, Zn, Mo, Hf, Sn, W, Li, Mg, Th, Cr, V, Zr and Mn. Metal--second phase composites Christodoulou, L., Nagle, D.C. and Brupbacher, J.M. (Martin Marietta Corporation, Bethesda, MD, USA) US Pat 4 916 030 (10 April 1990) A metal-matrix composite comprises about 5 volume % of uniformly dispersed, substantially unagglomerated, in situ precipitated particles in a metal, metal alloy or intermetallic matrix composed of intermediate metal and host metal. Ceramic composites reinforced with modified silicon carbide whiskers Tiegs, T.N. and Lindemer, T.B. (Martin Marrieta Energy Systems, Inc, Oak Ridge, TN, USA) US Pat 4 916 092 (10 April 1990) A ceramic matrix has elongated monocrystalline silicon carbide whiskers dispersed therein. The whiskers have a diameter of 0.1-10 [xm, an aspect ratio of greater than 10, and a surface characterized by an SiO2:SiC ratio of less than 0.1, less than 1.5 weight % calcium oxide concentration and coating of free carbon of 0.1-10 nm.
PROCESSES Method for attaching carbon composites to metallic structures and product thereof Pratt, W.N. and Haner, R.M. (General Dynamics, Pomona Division, Pomona, CA, USA) US Pat 4 907 733 (13 March 1990) A recessed pocket region is formed on the edge of a carbon composite material. This region forms pockets on both sides which are joined by a recess edge region. At least one hole is formed between the recessed surface of the pockets on opposite sides of the material. The pockets are plated with nickel to approximately the height of the surface of the material adjacent to the pockets. In situ reinforced structural diaphragm walls and methods of manufacturing (Taki, O., Belmont, CA, USA) US Pat 4 909 675 (20 March 1990)
The method comprises augering down into the soil with a three-shaft auger apparatus with two outer auger blades of the first diameter and an inner blade of a second diameter such that a set of coplanar, overlapping boreholes of alternating diameters are produced. A chemical hardener is injected into the soil during the augering. This hardener is mixed with the soil in the borehole and a structural member is inserted into at least some of the boreholes. The soil and chemical hardener blend is allowed to cure to form a hardened, reinforced, structural diaphragm wall. Process for making a fibre reinforced composite article Jarmon, D.C. (United Technologies Corporation, Hartford, CT, USA) US Pat 4 909 872 (20 March 1990) A tow of multifilament inorganic yarn is wound onto a mandrel and powdered glass matrix material and a binder mixture is spread over the tow to form a tape. A monofilament inorganic fibre is wound onto a mandrel and a binder applied to form a monofilament fibre tape. The monofilament fibre tape is then stacked between two multifilament tapes such that the monofilaments and the yarn fibres are parallel to each other, to form a hybrid composite ply. These plies are laid up in a selected pattern to form a composite preform and the whole is consolidated with heat and pressure to form a fibre-reinforced glass-matrix article with high strength, stiffness and fracture toughness. Yarns and tows comprising high strength metal coated fibres, process for their production, and articles made therefrom Morin, L.G. (American Cyanamid, ME, USA) US Pat 4 909 910 (20 March 1990) A continuous length of a plurality of electrically conductive, graphite core fibres is passed through a bath capable of electrolyticaUy depositing at least one metal. A voltage of 10 V is applied to the fibres immediately before immersion in the bath and this is maintained for such a time that a thin, uniform, electrically conductive layer of metal is deposited on the core to form composite fibres. Method of making graded structure composites Begg, A.R., Brown, C.W. and Charman, N.E.S. (The British Petroleum Company, pie, London, UK) US Pat 4 911 625 (27 March 1990) Components to form the following layers are packed sequentially into a container. Each layer is compacted under pressure before the next layer is introduced. The packed layers are decontaminated by fitting the container with a tight-fitting lid and then applying a vacuum via an aperture in the container or lid. The whole is evacuated under reduced pressure and is sealed before hot isostatic pressing at 1320-1360°C and 200 MPa for at least 1 h and then cooling at a rate of 10-200°C per minute so that the base steel plate transforms into a bainitic phase. The layers of the composite are a surface layer of tungsten carbide and a binder phase selected from cobalt, nickel and alloys thereof; an interface layer of tungsten carbide and a binder as in the surface layer except that the binder concentration is in graded steps increasing with depth; and a substrate layer
COMPOSITES . JANUARY