Explosive Compaction of powders,principle and prospects

The explosive compaction method consisting of a cylindrical container surrounded by a proper type and amount of explosive is an inexpensive method to achieve high densities close to theoretical density. The explosive's parameters have to be adjusted to the type of the powder to be compacted. The required explosive's pressure is linearly related to the Vickers hardness of the metal powder particles. If higher pressures are applied, an “explosive liquid phase sinter” - process can be achieved, allowing the welding of individual particles. The residual properties of the material are characterized by a high defect structure and by dislocation densities and subgrain sizes comparable to those after heavy plastic deformation. The same is true of compacted ceramic powders. Enhanced sinter reactivity, chemical and catalytic reactivity may be the result of high values of stored energy observed in the ceramic materials, shock wave treated under conditions of explosive compaction. The properties of materials produced by shock-wave synthesis or by shock-wave transformation are also determined by a high-density defect structure.