Electrical conductivity of copper powders under shock compression

The electrical conductivity of some compositions based on the copper powder under shock compression is measured. The commercial copper powder, mixtures of copper with glass microspheres, and copper–aluminum mixtures are studied. The electrical conductivity is measured by the author's electrocontact technique, which allows the insulator–metal transition to be measured. Dependences of the electrical conductivity of powders on the shock wave pressure are obtained. As for aluminum powders examined previously, this dependence for the copper powder has a nonmonotonic character. The maximum electrical conductivity is $\approx$ 9 $\cdot$ 10$^4$ $\Omega^{-1}$ $\cdot$ cm$^{-1}$. With a further increase in the shock pressure, the electrical conductivity decreases approximately by an order of magnitude, which is explained by intense temperature heating. The results for the electrical conductivity at high shock pressures is qualitatively consistent with known broad-range models of conductivity proposed by Garanin and Bakulin.