Effect of Composition on the Dielectric Properties of Electrical Porcelain.

Akinbami, John-Fekix Kayode (1987)


The effect of compositional change on the dielectric properties (i.e. dielectric constant, dielectric resistance, dissipation factor, loss factor) of Electrical Porcelain has been investigated. The evaluation was carried out using six different compositions. The capacitance and resistance of the samples of the six different compositions over a frequency range of 10 to 105 Hertz were measured. From these experimentally obtained values of resistance and capacitance, the values of the dielectric properties mentioned above were calculated. The samples of the six different compositions were compacted under four different compaction pressures: 2.2 x 108 N/m2, 3.0 x 108 N/m2, 3.2 x 108 N/m2 and 3.5 x 108 N/m2, and fired at four different temperatures: 1250°C, 1300°C, 1350°C and 14000C, and the samples were of varying thicknesses ranging from 2.5mm to 8mm. Available information from the present work suggest that sample “C” with composition, Kaolin, 39.25%; Feldspar, 24.50%; and Quartz, 36.25% gives the best dielectric properties of all the six different compositions. The most probable firing temperature, so as to avoid over firing as well as allow for dense formation to give good dielectric properties of the wares produced, is 1350°C.