The double explosive layer cylindrical compaction method

The standard cylindrical configuration for shock compaction is useful for t he compaction of composite materials which have some plastic behavior. It c an also be used to densify hard ceramics up to about 85% of the theoretical density (TMD), when low detonation velocity explosives (2-4 km s(-1)) are used. In order to attain higher densities, higher pressures will be needed. With the aid of computer simulations, it is shown that this can be realize d without the risk of tensile rarefaction waves, by using two layers of exp losives having different detonation velocities. This method has already res ulted in a homogeneous B4C compact (87% TMD). After infiltration with Al, a B4C composite having a hardness ranging from 15 to 18 GPa could be obtaine d with this method. (C) 1999 Elsevier Science S.A. All rights reserved.