Thus,
hydrostatic figure of merit (HFOM, dh gh), defined to evaluate
the overall performance of a piezoelectric ceramic used as a
hydrophone, can be significantly improved. Third, porous PZT
ceramics provide a solution to the problem of poor acoustic
matching between ceramics and media for their low density. In
short, porous PZT ceramics have emerged as a promising
candidate over dense materials in many applications. Consequently, a large amount of research has been carried out
involving various manufacturing techniques to produce porous
PZT ceramics [6–8] and parameters possibly influencing their
properties [9–12]. The key problems in this area mainly involve
the conflicts between desired porosity and mechanical strength,
piezoelectric properties and anti-interference ability. Although
almost all manufacturing techniques have their own limitations
or drawbacks, they offer alternative perspectives to the
acquisition of porous PZT ceramics with certain merits. In
addition, the sintering behavior, which relates directly to the
microstructure of pores and exerts significant influence on the
final piezoelectric properties, lacks sufficient investigation.
Therefore, the aim of this paper is to fabricate porous PZT
ceramics with high strength by using a novel tert-butyl alcohol
(TBA)-based gel-casting method. Furthermore, it is the aim to
characterize the sintered ceramics in terms of both micro