Abstracts of patents Ahstruc’ts
by Dr R.J. Hand, Department of Engineering Materials, University of Shefield
US PATENTS Golf club bead Fukayama, T., Sugioka, Y. and Soeda, T. (Mizuno Corporation, Osaka and Tokyo Yogyo Company, Tokyo, both of Japan) uis Put 5 037 102 (6 August 1991) A gold club head is formed by mixing a ceramic powder (Sic, Si,N,, Al,O,, B,C, BN, ZrO,, Tic, WC, SiO,, MgO, TiO,, Y,O,, Cr,O,, CrC,, TiN, ZrB,, TiB,, and Sialon) with a molten Al alloy. The face portion, which contains l-50 volume% ceramic, is then formed by hot pressing. The whole is then die cast and finally the composite face portion proper is formed. Hot-melt prepreg tow apparatus Angell, R.G., Michno, M.J., Konrad, J.M. and Hobbs, K.E. (Amoco Corporation, Chicago, IL, USA) US Pat 5037284 (6 August 1991) The apparatus consists of a strand feeder which supplies continuous fibre strand to a working area, where it is formed into a band. The band is impregnated with a molten, solvent-free resin by a number of rolling dies to form an impregnated tape which is chilled on at least one chill roll before being taken up at the end of the process. Method and apparatus for forming fibre reinforced plastic preforms from a wet slurry Freeman, R.B. and Greve, B.N. (The Budd Company, Troy, MI, USA) US Pat 5 039 465 (13 August 1991) A screen of the desired preform shape is placed near the bottom of a liquid-filled tank. Fibres are added to the liquid and the screen is drawn up to the top of the tank so that the fibres are deposited on the screen. The preform is removed using a vacuum pick-up and impregnated with resin in a mould. Method for forming macrocomposite bodies and macrocomposite bodies produced thereby Newkirk, M.S., White, D.R., Kennedy, C.R., Nagelberg, AS., Aghajanian, M.K. and Wiener, R.J. (Lanxide Technology Company, LP, Newark, DE, USA) US Pat 5040588 (20 August 1991) A filler or preform body is brought into contact with a metal reservoir. On melting, the metal infiltrates the preform to produce a metalmatrix composite; additionally it penetrates a second body which is placed beyond the first preform, thereby bonding the second body to the metal-matrix composite. The second body has a greater thermal expansion coefficient than the composite and thus the composite is placed in compression on cooling. Method of resin transfer moulding a composite article Johnson, C.F. (Ford Motor Company, Dearborn, MI, USA) US Pat 504.5251 (3 September 1991) Fibre reinforcement material is applied to the outer surface of a core which contains a
number of internal passages. At least one of these passages connects to an inlet and at least one (not connected to the first) to an outlet. The resulting preform is placed in a moulding tool and impregnated with uncured resin which is introduced via the inlet; the resin is vented via the outlet and the result is cured to produce the composite. Dual processing of aluminium base metal matrix composites Das, S.K., Zedalis, M.S. and Gilman, P.S. (Allied-Signal Inc, Morris Township, Morris County, NJ, USA) US Put 5045278 (3 September 1991) A charge comprising a rapidly solidified aluminium base alloy, O.OlllO weight% of a carbidiferous agent and 0.1-50 volume% particulate reinforcing material is energetically ball-milled to mix the carbidiferous agent with aluminium matrix and to enfold the matrix round each of the reinforcement particles. The whole is consolidated such that the aluminium and the carbidiferous agent react to produce carbides and oxides. The result is a mechanically formable, void-free mass. Fibre-reinforced thermoplastic polymer composite and process for preparation thereof Glemet, M. (Atochem, Courbevoie, France) US Pat 5047263 (10 September 1991) The fibre reinforcement is wetted with a thermoplastic polymer which results from the polyaddition of a polyamide oligomer and a reaction partner or a sequenced poly(etheramide) copolymer. Polyamide is applied over this, and the whole is heat-cured to produce a unitary composite. Method for thermostamping thermoplastic composites Giles, H.F. and Shelby, N.C. (General Electric Company, Pittsfield, MA, USA) US Pat 5049323 (17 September 1991) A composite comprising non-woven fibres, thermoplastic resin and a radio-frequency sensitizing agent is convection heated to the glass transition of the resin. It is then radio frequency heated to a temperature between the melting temperature of the resin and 100°C above this, at which temperature it is stamped to produce a shaped article. Method and apparatus for manufacturing continuous fibre glass strand reinforcing mat Reese, W.J., Morfesis, A., Salego, G.T. anu Vorp, D.A. (PPG Industries, Inc, Pittsburgh, PA, USA) US Pat 5051122 (24 September 1991) A loose fibrous mat is formed by reciprocating strand feeders passing over a conveyor. Resin is distributed generally throughout this structure. It then passes round a calendering roll such that the mat and the resin are compressed between the calendering roll and the conveyor. After this it is heated to remove moisture and melt the resin, thus bonding the mat together.
Method of moulding composite articles Donatelli, J.M., Mhah, G.C. and Brady, S.A. (Dow Corning Corporation, Midland, MI, USA) US Pat 5 051224 (24 September 1991) A prepreg is placed over a master tool within a mould and silicone crumb rubber placed over it. This rubber contains at least 20 mol% unreacted vinylorganosiloxane units to make it resistant to depolymerization at 535°C. The whole is then heated at at least 535°C to form and cure the composite body (the rubber expands on heating and thus compresses the prepreg against the mould). The composite and crumb rubber are removed from the mould once the tool has been cooled. Production of fibre reinforced ceramic composite Birchall, J.D. and Clegg, W.J. (Imperial Chemical Industries plc, London, UK) US Pat 5053 175 (1 October 1991) A precursor comprising particulate ceramic, a liquid diluent and organic binder is formed. The precursor also contains fibres formed from these components. The whole is heated to remove the diluent and the binder and to sinter the ceramic particles that are in both the matrix and the fibres. Aluminium borate ceramic matrix composite Ray, S.P. (Aluminium Company of America, Pittsburgh, PA, USA) US Pat 5053364 (I October 1991) A slurry of aluminium oxide, boron oxide and an organic binder suspended in a liquid is infiltrated into a ceramic fibre body, the liquid and the organic binder are removed and the whole is sintered at greater than 800°C to produce fibre-reinforced AI,B,O, where 16 < x < 20,3 < y < 5 and 30 < a < 36. The fibres may be silicon carbide, alumina, alumina-boria-silica, titanium boride, boron, carbon, aluminium silicate or aluminium nitride. Process for continuously forming reinforced articles Vane, J.A. (Tech Textiles Ltd, Andover, UK) US Pat 5055242 (8 October 1991) Yarns of fibres are continuously laid down in non-interwoven layers and at least two of the layers have the fibres extending in different directions. The layers are stitched together and wetted with a matrix material, after which they are formed into a desired article and cured to produce the finished article. Electric alignment of fibres for the manufacture of composite materials (Knoblach, G.M. of Roseville, MN, USA) US Pat 5057253 (I5 October 1991) Electrodes are placed in locations corresponding to the load-bearing surfaces of the desired composite component and an electric field is applied between them. Prepreg rods with a density greater than a dielectric field are dispersed in this fluid in a tank and are allowed to fall to the bottom of the tank so that they