Influence of porosity and pore size on electrical resistivity of porous aluminum produced by spacer method

Abstract

Porous Al specimens with a pore size range from 212–300 to 850–1000 μm and a porosity range from 77 to 90% were produced by the powder-metallurgical spacer method, and their electrical properties were experimentally investigated. The electrical resistivity increased with an increase in porosity; on the other hand, it was negligibly affected by the pore size when the pore size was sufficiently small. The experimental results agreed with the theoretical results obtained using the unit-cell model in which size of apertures at cell walls are taken into consideration. However, at the maximum pore size in the range investigated, the measured value was much higher than the calculated one. This is likely to be related to the large variation in the local density of the cross section.