2026/07/20 by Muhammad Shafique Noor Azman, Valentina Torres Nieto, Marcia A. Cooper
Engineering · Materials Science · #Conductivity #Electrical conductor #Electrical resistivity and conductivity #Granular flow and fluidized beds #Lattice Boltzmann Simulation Studies #Material Dynamics and Properties #Particle (ecology) #Percolation (cognitive psychology) #Percolation threshold #Piezoresistive effect #Porosity #Porous medium
paper · doi:10.1016/j.powtec.2026.122962
published in Powder Technology 484, 122962 (Elsevier BV)
openalex publication_date 2026/07/20 · openalex created_date 2026/07/21 · openalex updated_date 2026/07/30
This study investigates the coupled mechanical compression and electrical transport behaviors in porous powder mixtures. Composed of discrete particles with unique sizes, shapes, and strengths, these mixtures form a disordered mesostructure that evolves during densification, giving rise to the bulk properties of the solid-like porous material. Utilizing a custom uniaxial apparatus, we generated temporally resolved stress-density-conductivity datasets for copper and copper(II) oxide mixtures, spanning variations in particle strength, intrinsic conductivity, morphology, and size distribution. We apply effective media and statistical pressure-volume models from the literature to correlate bulk behaviors with specific physical regimes: the near-jamming limit, deformation-free rearrangement, the percolation threshold, and pressure-activated void filling. While relative density increased monotonically with applied force across all samples, conductivity exhibited irregular trends in mixtures where rearrangement ceased before establishing a stable percolating network. These findings suggest that electrical conductivity serves as a high-sensitivity diagnostic for internal microstructural evolution and particle mobility. Finally, we evaluate the applicability of piezoresistive gauge factors to granular media, highlighting the inherent challenges in characterizing discrete particle systems. This work provides a foundation for subsequent studies on how particle morphology dictates percolation behavior and particle-scale mechanisms during the densification of conductive powder mixtures.