Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials

By E. Herbold, V. Nesterenko, D. Benson, J. Cai, Kenneth S. Vecchio, F. Jiang, J. Addiss, S. Walley, W. Proud. 2008

143 citations recorded by the source corpus.

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a drop-weight test. Macrocracks forming below the critical failure strain for the matrix and un...

Subfields: Materials Chemistry, Mechanics of Materials, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/6194a2b07bf4e609cfedc6cd72937f68e84f2a7b