stress it is shown that fatigue life increases rapidly as the aspect ratio rises to 200 but that it is slower after this value. Static strength is found to remain sensibly constant at aspect ratios of 200 or more which is of importance in fabrication because difficulties due to decreased ductility of the mixture tend to be a combination of interfacial failure and rupture of the matrix at 45 ° to the fibre axis. (70[3/28) LIESNER, C. and WASSERMAN, G.
Deformation behaviour and mechanical properties of composite materials of copper with ~t-alumina (in German) Zeitschrift Fiir Metallkunde Vol 60, No 11, pp 827 - 835 (1969) A study was made of the mechanical properties and response to mechanical working and heat treatments of materials composed of A I 2 0 3 particles in a matrix of Cu. The properties were measured as a function of particle content (up to 10 vol %) and size. The effectiveness of the A1203 in improving hardness and strength increased with decreasing particle size as well as with decreasing particle spacing. Extrusion of the composites produced textures which caused considerable anistropy of mechanical properties even after annealing treatments. This effect became relatively less significant at higher volume fractions of A 1 2 0 3 . (70[3/29) POND, R. J. R. and MADDIN, R. A method of producing rapidly solidified filamentary castings Transactions A IME 1Iol 245, No 11, pp 2 4 5 7 - 2476 An apparatus is described for producing long filaments of rapidly solidified metals and alloys. The molten alloy is ejected through a sapphire orifice onto the inside of a rotating drum. In this way, continous filaments have been produced with lengths of over 7m, thicknesses in the range 5 - 50/am and widths of 0.2 to 1.5mm. (70/3/30)
solidification and its tensile properties were measured after different amounts of cold rolling. Up to 98% reduction was achieved by rolling in a direction perpendicular to the fibre orientation but as little as 15% reduction produced edge cracking in material being rolled in a direction parallel to the fibre orientation. By rolling in the perpendicular direction, both the longitudinal and transverse tensile strength could be almost doubled. The treatment produced elastic bending of the fibres and for reduction greater than 75%, fibre fracture and misalignment was significant. The rolling also produced a fine dislocation substructure in the matrix adjacent to the fibres. This could be removed by annealing at 500°C with a consequent reduction in tensile strength. (70/3[3 I)
SHEEHAN, J. E. and HIRSCHHORN, J.S. Fibre breakage during powder metallurgy fabrication of aluminium-boron composites American Society o f Metals Transactions Quarterly, Iiol 62, No 3, pp 804 - 805 Mixtures containing 5 and 15 vol% in A1 powder were fabricated by cold compacting or hot pressing at different pressures to give specimens of various densities. The fibre lengths were measured after fabrication by dissolving away the matrix and it was found that the degree of fibre breakage increased with the specimen density. For composites that approached 100% theoretical density the majority of fibres were less than 17% of their original length. Less than 10% of the fibres were greater than half their original length. (70/3/32)
Resin matrices
and
ADAMS, R. D., FOX, M. A. O., FLOOD, R. J. L., FRIEND, R. J. and HEWITT, R. J.
Some effects of cold rolling on the microstructure and properties of AlaNi whisker reinforced aluminium
The dynamic properties of unidirectional carbon and glass fibre reinforced plastics in torsion and flexure Journal
Transactions AIME Vol 245, No 10, pp 2339 - 2345
o f Composite Materials Vol 3 pp 594 - 603 (October 1969)
Aluminium reinforced with AIaNi fibres was produced by directional
Torsional and flexural vibrations were applied to composites of E glass and
SALKIND, TICE, W.
]86
M.,
GEORGE,
COMPOSITES March 1970
F
type I carbon fibre in polyester resin. For both systems damping E l l and G I~ were independent of cyclic stess amplitude, and damping was observed to decrease as the fibre volume fraction increased. Good agreement between theory and experiment was observed for both flexural and longitudinal shear moduli. (70/4•30)
BACON, C. E. Fibrous reinforced plastics in appliances and equipment Reinforced Plastics, Vol 14, No 3, pp 6 6 - 7 8 (November 1969) An account is given of the use that has been made of F RP by various manufacturers in the construction of refrigerated display units, air conditioners, humidifiers, storage tanks, dishwashers, etc. The author predicts that FRP will continue to find such applications at an accelerated rate. (70/4[31)
BARTON, R. S., BALDWIN, R. B. and HENSHAW, J. Avco 3-D composites: a tailored concept Reinforced Plastics, Vol 14, No 2, pp 42 - 46 (October 1969) To reduce interlaminar weakness in composites based on a polymer matrix and fabric reinforcement, a method for weaving a three-dimensional fabric has been developed. Solid blocks up to 8 x 8 x 18in are made thus, vacuum impregnated with polymer and suitable cured. Size and shapes obtained in this way are almost unlimited. Tensile strength parallel to the ply of a comparable laminate is not much reduced in the 3-D version, but lateral strength is improved by at least an order of magnitude. (70•4•32)
BROWN, G. F. Marketing reinforced plastics; general industrial mouldings Plastics and Polymers, Vol 37, No 132, pp 529 - 531 (December 1969) Effective marketing of G RP in the general moulding industry is difficult and has been largely neglected. The author attempts to rationalize the market and suggests that G R P moulders should identify more closely with the particular industries they serve. (70/4/33)