Shock-wave compaction of porous aluminum

Abstract

Experimental data on the shock-wave compaction of 78% dense porous aluminum are presented and compared with theoretical predictions from a mathematical theory of time-dependent pore closure for ductile materials with isolated spherical voids. A recently modified form of the theory was used which includes deviatoric stresses and material viscosity. Incorporation of the work-hardening properties of the solid resolved previous discrepancies between measured hydrostats and predictions assuming elastic-perfectly plastic deformation of the matrix. Generally good agreement was also observed between experimental quasistatic and shock data, although there was some evidence that the quasistatic data were strain-history dependent. Finally, a satisfactory check of the theory was obtained by comparing predicted steady-wave rise times with measured stress-wave profile data. These results suggest that the current version of the theory is a significant improvement over past models, because it permits a more accurate estimate of the influence of both pore size and the plastic deformation characteristics of the metal matrix on shock compaction.