Electrical behaviour of attritor processed Al/PMMA composites

Al/PMMA composites containing different volume fractions of aluminium were prepared by attritor milling followed by hot pressing and their thermal expansion and electrical behaviour were studied. Room temperature resistivity of these composites dropped by several orders of magnitude when the volume percent of aluminium ranged between 20 and 40 vol.%. Microstructural examination revealed the presence of continuous chains of aluminium in highly conducting composites. The dielectric constant and dissipation factor of the composites increased with increase in aluminium content. This has been attributed to the interfacial polarization associated with aluminium particles.