PROPERTIES OF IRRADIATED SILICA FIBRE REINFORCED ALUMINUM

Samples of silica-fibre-reinforced aluminum have been irradiated at 35, 300 and 410 °C to determine their utility in the reactor environment. In addition, the constituents were irradiated separately. Tests on the composites indicate that they may be used at high stresses at temperatures only up to about 300 °C, are not degraded by irradiation up to a dose of 3-5 × 1019 nfvt at this temperature, and gain strength on being irradiated at about 35 °C. Tests on the constituents indicate that silica fibres lose strength as a result of irradiation, but not to an extent likely to affect the composite except over a long period (≫ 1 year at fluxes in the region of 2 × 1012 nfv), and that the reason for the increase in strength of the composite when irradiated at about 35 °C is the increase in flow stress of the aluminum produced by the irradiation. The effect on composites of changes in the flow stress of the matrix material is discussed, and it is shown that in general the higher the flow stress of the matrix the stronger the composite will be, so long as the material does not become notch brittle. © 1969.