Electrical resistivity of a titanium powder mass

Abstract

In this paper, the variation with the porosity of the electrical resistivity of a compressed powder mass of commercially pure titanium has been studied. The study has been carried out via the direct measurement of the electrical resistance of a powder column subjected to uniaxial compression. The obtained experimental data have been fit to a theoretical model, proposed by the authors in a previous work, which allowed calculation of the effective electrical resistivity of the metallic powder aggregate as a function of its porosity level. This model considers not only the two obvious parameters (the porosity of the powder aggregate and the electrical resistivity of the material that constitutes the powder particles), but also the morphometry of the powder (represented by its mean particle radius and its tap porosity) and the electrical and mechanical characteristics of the oxide layer that surrounds all metallic powder particles. The results obtained from the present study allow determination of the electrical resistivity of a Ti powder aggregate, regardless of the porosity level of the powder. This knowledge is of great importance for the modeling of increasingly complicated electrical consolidation methods.