Thermal degradation of silica fibre-reinforced aluminium

Thermal degradation of silica fibre-reinforced aluminium

state decomposition are reviewed. It is suggested that solid-state growth methods may be classified, according to the state of the starting material, ...

131KB Sizes 1 Downloads 42 Views

state decomposition are reviewed. It is suggested that solid-state growth methods may be classified, according to the state of the starting material, into eutectoid decomposition; discontinuous precipitation; or growth from noncrystalline state. The theory of transformation, experimental techniques and empirical parameters reported in the literature are considered. The relationships between interphase spacing and growth rate, and potential discrepancies between growth and pulling rates, are emphasised.

A procedure for the reduction and sintering of agglomerated, finely divided iron oxide to give porous iron pellets suitable for infiltration (short communication) Sparks, B.D. and Meadus, F.W.

Powder Technology Vo119 No 1 (January/February 1978) pp 119-120 The procedure is used to prepare porous iron pellets which are subsequently infiltrated with molten lead. The lead/iron composite pellets are used as shot.

Production of stainless steel wire reinforced aluminium composite sheet by explosive compaction Bhalla, A.K. and Williams, J.D.

Journal of Materials Science Vo112 (March 1977)pp 522-530 Composite sheet material has been produced by explosively compacting stacks of alternately placed stainless steel wire meshes and aluminium foils using an aluminium driver plate. Six or seven layers of mesh giving a wire volume fraction of up to 0.24 could be bonded with driver plate kinetic energy exceeding 120 J/cm 2 . It is concluded that the bonding mechanism involves cold pressure welding of the matrix metal by extrusion through the mesh apertures, the aperture size being a controlling factor. Tensile and fatigue properties compare favourably with other aluminium composites and with high strength aluminium alloys.

have a significant influence on the magnetic properties of the composites measured in the direction of the fibre axes and this is thought to be related to the presence of stresses induced in the matrix during cooling from the heat treatment temperature used in the fabrication process.

Composite properties of an aramid fiber in a room-temperature-curable epoxy matrix

Thermal degradation of silica fibrereinforced aluminium

SAMPE Quarterly Vol 9 No 1 (October 1977) pp 6-12

Squires, H.V. and Rayson, H.W.

A characterization programme was conducted on filament wound aramid fibre/epoxy composites. It was found that the room temperature longitudinal tensile properties of the composite are good, although the transverse tensile uts and strain are low (as is typical for aramid fibre/epoxy composites). Thermal properties were found to change above about 50°C, and a reduction in transverse tensile strength was noted at 54°C. It is suggested that these two factors will limit the potential applications of the material.

Clements, L.L and Moore, R . L

Journal of Materials Science Vo112 (May 1977) pp 1010-1018 At elevated temperatures, the aluminium matrix reduces the reinforcing silica fibres to silicon, severely lowering the mechanical properties. Fibres corrode at a constant rate at a fixed temperature. The possibility of developing a strong, fibre-reinforced material by completely reacting the silica and replacing it with the more stable alumina reaction product has been considered but success is unlikely because of associated porosity formation. RESIN MA TRICES

Assessment of damage in grp laminates by stress wave emission and dynamic mechanical measurements Sims, G.D., Dean, G.D., Read, B.E. and Western, B.C. Journal of Materials

Science Vo112 (November 1977) pp 2239-2342 Stress wave emission and dynamic mechanical methods are described for monitoring the damage introduced into certain glass fibre-reinforced epoxy specimens by the application of a tensile load. For one cross-ply laminate it was possible to measure the concentration of damage by an independent optical method and correlation has been found between the two methods. The work is considered as a first stage towards using these methods for monitoring the integrity of a component in service, from which its remaining life might be assessed.

Journal of Materials Science Vo112 (March 1977) pp 434-442

A comparison of methods for determining the shear properties of glass/resin unidirectional composites Loveless, H.S. and Ellis, J.H. Journal o f Testing and Evaluation Vol 5 No 5 (September 1977) pp 369-374

Composites containing tungsten wires in nickel and nickel-iron alloy matrices were fabricated by a filament winding-electroplating technique. The presence of the fibres was found to

A new notched rod shear test for unidirectional composites is compared with the short beam and torsion tests. The new test eliminates the tensile failures that sometimes occur in the

Some magnetic and mechanical properties of fibre reinforced nickel and nickel-iron alloys. Marsden, A.L. and Jakubovics, J.P.

206

other two tests and the current experiments suggest that shear strength at the interface can exceed that of the resin matrix.

Compressive fracture in unidirectional glass-reinforced plastics Chaplin, C.R. Journal of Materials Science Vo112 (February 1977) pp 347-352 A shear mode mechanism of compressive failure in unidirectional fibre composites is described in which the shear deformation is restricted to a band of material inclined to the plane normal to the fibre axes. The relationship between the orientation of the failed band of material and the limiting shear deformation in the band is explained in terms of volumetric strains. The sequence of events in the propagation of compressive failure was studied by examining serial sections of an arrested failure.

Crack growth in hybrid fibrous composites McColl, I.R. and Morley, J.G. Journal of Materials Science Vo112 [June 1977) pp 1165-1175 An analysis of the energetics of transverse transverse crack growth in a brittle elastic matrix bridged by elastic fibres frictionally bonded to the matrix was shown to predict crack stability for model composites of steel wires in brittle polymeric matrices. It is proposed that the stability of transverse cracks in a very brittle matrix could be increased substantially by the introduction of a second fibre component designed specifically to increase the work of fracture of the matrix. Experiments with steel and glass

COMPOSITES. JULY 1978