Rate of creation of the contacts between grains in a loose array of particles submitted to an uniaxial pressure

Macroscopic resistivity measurements have been performed on TiC/Al2O3 random mixtures submitted to uniaxial compression (0–95 kN). Such a random mixture exhibits an insulator-conductor transition which appears at increasing force while decreasing the conductive composition of the TiC/Al2O3 mixture. It is demonstrated that the conductivity behavior may be understood in the framework of a site percolation model. Finally, the rate of creation of the contacts between conductive grains is extracted from the macroscopic resistivity measurements. PACS. 45.70.Cc Static sandpiles; granular compaction – 72.80.Tm Composite materials