Developments in Ceramic Materials Research

C
0
S
ε 33 A
=
2t
where A is the surface area of the electrodes.
Progress in Porous Piezoceramics 221
3.2. Variation of material parameters with ceramic volume fraction
The material parameters of the 3-3 piezocomposites are estimated using the present
model. Figures 1-3 show the variation of material parameters of a piezocomposite as a
function of ceramic volume fraction. In all the figures, the solid lines represent the analytical
data and markers represent the experimental data.
Figure 1 shows the variations in the dielectric constant
(14)
T
K 33 , piezoelectric charge
coefficients d 33 , d 31 and d H , voltage coefficient g H and Figure-of Merit ( d H g H ) as a
function of ceramic volume fraction. Figure 5a shows the variation of dielectric constant with
ceramic volume ratio. For low ceramic volume fractions, the experimentally measured values
are very close to the predicted values.
Figure 5. Variation of (a) dielectric constant, (b) hydrostatic d coefficient, (c) hydrostatic g coefficient
and (d) hydrostatic Figure-of-Merit, with ceramic volume fraction. Markers are the experimental data
and solid lines are the analytical curves.