Development of beryllium-carbide fibre reinforced beryllium for fusion applications

Be-Be₂C composite materials have been produced via two routes. The first produces a two dimensional composite with woven carbon cloth converted to the Be₂C fibres and infiltrated with molten Be with the assistance of a wetting agent. A number of wetting agents with low atomic number were tried, the best being silicon, either in metallic form or as polydimethylsiloxane. The second composite has a three dimensional structure, again with Be as the matrix but with random Be₂C fibres, produced by hot pressing a mixture of Be powder with 0.25 inch Be₂C fibres; no wetting agent was used. Some fibre agglomeration was observed with resulting porosity and the component had a density of 93% of theoretical. The room temperature thermal conductivity of the second composite was 84W/mk, slightly less than would be expected by a rule of mixtures, possibly due to the porosity