High strain rate compression behaviour of closed cell aluminium foam reinforced with copper coated carbon fibres

Aluminium foams containing 1.7 vol.-% copper coated carbon fibres were fabricated by a melt route using TiH2 foaming agent. The compressive behaviour of closed cell aluminium foams is studied under quasi-static and dynamic loading conditions. The dynamic tests were conducted using a split Hopkinson pressure bar apparatus with a maraging steel bar. The results indicated that plateau stress of aluminium foams with copper coated carbon fibres is higher than that without copper coated carbon fibres in both quasi-static and dynamic compression tests. The apparent strain rate sensitivity of plateau stress has been observed. The plateau stress increases with strain rate. The strain rate effect was more significant for higher density aluminium foam and the energy absorption capacity of aluminium foams increases at high strain rates. The apparent increase in the strain rate sensitivity can be attributable to the additional effect of gas pressure in the closed cell.