Abstract: A treatment process for a composite comprising a matrix of a precipitation hardenable aluminum alloy and a particulate or short fiber ceramic reinforcement. The process includes hot and/or cold working the composite, subjecting the composite to a controlled heating step in which the composite is raised from ambient temperature to a temperature of from 250 to 450.degree. C. at a rate of temperature increase less than 1000.degree. C. per hour, and subjecting the resulting heat treated composite to a solution treating step.

Abstract: A magnesium-free aluminum alloy suitable for use as the matrix alloy in a metal matrix composite material is disclosed which overcomes the drawback of the rapid natural ageing response exhibited by prior art alloys. This facilitates greater flexibility in manufacturing with metal matrix composites because of the improvement in fabricability. The alloy composite comprises 1 to 50% by weight of reinforcing material embedded in a matrix alloy having the following composition in proportions by weight: copper 4-6%, aluminum the balance, save for incidental impurities, and further comprising one of the grain refining additives from the group comprising zirconium, manganese or chromium in an amount up to 0.5% by weight.

Abstract: The stiffness of materials formed from aluminum alloy sheets laminated with layers of long aligned fibers embedded in a matrix of resin material is enhanced by reinforcing the aluminum alloy component with ceramic particles or whiskers. Use of stiff fibers such as carbon, aramid, alumina, silicon carbide or mixtures of these enables the stiffness of the fiber/resin component to be matched to that of the metal/ceramic component. This results in good fatigue crack growth resistance in the finished laminate, even for short crack lengths. In a preferred laminate, the metal/ceramic component is formed with a matrix of aluminum-lithium alloy. Such alloys are inherently stiffer than alloys without lithium, with the result that the increased stiffness obtained from ceramic reinforcement is enhanced stiff further.

Abstract: A suitable precursor for the production of carbon fibre is an acrylonitrile copolymer containing at least one non-acrylic moiety which is a carbonyl group a hydroxymethylene group, --CH(OH)-- or a two carbon moiety containing a carbonyl group or a hydroxymethylene group and in which the non-acrylonitrile moiety is present to the extent of 5 to 15 molar parts per 100 molar parts of acrylonitrile moiety.The preparation of such copolymers and their conversion to carbon fibre is described.

Abstract: A process for the production of carbon fibres is described in which a precursor fibre which is a copolymer of acrylonitrile, a chlorinated monomer, and itaconic acid containing between 2 to 20 molar parts of chlorinated comoner, between 0.5 and 5 molar parts of itaconic acid and 0 to 5 molar parts of other comonomers per 100 molar parts of acrylonitrile to a temperature in the range 200.degree.-400.degree. C while the natural shrinkage of the fibre is at least restrained followed by further heat treatment at a temperature in the range 800.degree.-3000.degree. C in a non-oxidizing atmosphere.