Provided is a piezoelectric single crystal-polycrystal ceramic composite, a method of manufacturing the same, and piezoelectric and dielectric application components using the piezoelectric single crystal-polycrystal ceramic composite. The piezoelectric single crystal-polycrystal ceramic composite shows that complexation is carried out by the optimization of a ratio between grain size distributions of a piezoelectric single crystal and polycrystal ceramic grains, and a volume ratio of the contained piezoelectric single crystal so that mass production simultaneously with excellent piezoelectric characteristics of the piezoelectric single crystal can be realized, and the cost of production can be reduced, so the piezoelectric single crystal-polycrystal ceramic composite can be applied to piezoelectric and dielectric application components, like ultrasonic transducers, piezoelectric actuators, piezoelectric sensors, dielectric capacitors, electric field-generating transducers, and electric field and vibration-generating transducers, using the piezoelectric single crystal-polycrystal ceramic composite, and the piezoelectric single crystal-polycrystal ceramic composite can enhance piezoelectric characteristics and competitiveness in prices.

A dielectric composition includes dielectric particles and segregation phases. The dielectric particles each include Ca and/or Sr. The segregation phases each include Mn, Si, O, and at least one selected from Ca and Sr.

[Object] To provide a porous piezoelectric material molded body highly useful as a constituent material of a piezoelectric transducer suitable, in particular, for a probe of medical ultrasound diagnosis equipment. [Solution] A porous piezoelectric material molded body, in which 1000 or more spherical pores with an average pore diameter in the range of 2 to 70 μm are dispersedly formed per volume of 1 mm3, is characterized in that there is substantially no pore with a pore diameter larger than 50 μm, and 80% by volume or more of the total pores that constitute a spherical pore group have a pore diameter within ±20% of the average pore diameter.

A process for preparing a porous ceramic body includes forming a green body with a mixture of ceramic material powder, binder material, and pore-forming particles. The process further includes extracting the binder material, decomposing the pore-forming particles, and removing residual organic materials from the green body at respective, progressively higher pre-firing temperatures. After these three stages, the green body is sintered at a still-higher temperature to form the porous ceramic body. Embodiments facilitate manufacturing and can render most or all surface grinding unnecessary, allowing electrode deposition directly onto substantially non-porous surfaces of the porous ceramic body that are naturally formed during sintering. Advantageously, the green body may be formed into net shape by injection molding the mixture that includes the pore-forming particles, and embodiments can result in porous ceramic bodies that are much thicker than currently available, with better structural integrity.

A process for preparing a porous ceramic body includes forming a green body with a mixture of ceramic material powder, binder material, and pore-forming particles. The process further includes extracting the binder material, decomposing the pore-forming particles, and removing residual organic materials from the green body at respective, progressively higher pre-firing temperatures. After these three stages, the green body is sintered at a still-higher temperature to form the porous ceramic body. Embodiments facilitate manufacturing and can render most or all surface grinding unnecessary, allowing electrode deposition directly onto substantially non-porous surfaces of the porous ceramic body that are naturally formed during sintering. Advantageously, the green body may be formed into net shape by injection molding the mixture that includes the pore-forming particles, and embodiments can result in porous ceramic bodies that are much thicker than currently available, with better structural integrity.

A piezoelectric material having a large electromechanical coupling coefficient is provided. The material is manufactured by a method including the steps of: heating a piezoelectric material having a low-temperature side ferroelectric phase A and a high-temperature side ferroelectric phase B between which the phase of the piezoelectric material transitions according to a temperature change, from room temperature to a temperature range higher than T.sub.(B.fwdarw.A) at which temperature a change from the ferroelectric phase B to the ferroelectric phase A occurs in a temperature lowering process and lower than T.sub.(A.fwdarw.B) at which temperature a change from the ferroelectric phase A to the ferroelectric phase B occurs in a temperature rising process; starting application of an electric field to the piezoelectric material in a state where it is held within this temperature range; and continuing and finishing the electric field application at a temperature lower than T.sub.(A.fwdarw.B).

The present invention relates to a bismuth-based solid solution ceramic material, as well as a process for preparing the ceramic material and uses thereof, particularly in an actuator component employed, for example, in a droplet deposition apparatus. In particular, the present invention relates to a ceramic material having a general chemical formula (I): (I): x(Bi.sub.0.5Na.sub.0.5)TiO.sub.3-y(Bi.sub.0.5K.sub.0.5)TiO.sub.3-z.sub.1SrHfO.sub.3-z.sub.2SrZrO.sub.3, wherein x+y+Z.sub.1+Z.sub.2=1; y, (z.sub.1+z.sub.2)≠0; x≥0. In embodiments, the present invention also relates to a ceramic material having a general chemical formula (II): x(Bi0.5Na0.5)TiO3-y(Bi0.5K0.5)TiO3-y(Bi0.5K0.5)TiO3-ZiSrHfO3-z2SrZrO3, wherein x+y+z−i+z2=1; x, y, fa+z2)≠0; as well as a ceramic material of general formula (III): y(Bi.sub.0.5K.sub.0.5)TiO.sub.3-z.sub.1SrHfO.sub.3-z.sub.2SrZrO.sub.3, wherein y+z.sub.1,+z.sub.2=1; y, (z.sub.1+z.sub.2)≠0.

Provided is a dielectric composition which includes, as a main component, a complex oxide represented by a general formula A.sub.aB.sub.bC.sub.4O.sub.15+α and having a tungsten bronze structure, wherein “A” includes at least Ba, “B” includes at least Zr, “C” includes at least Nb, “a” is 3.05 or higher, and “b” is 1.01 or higher. In the dielectric composition, when the total number of atoms occupying M2 sites in the tungsten bronze structure is set to 1, the proportion of “B” is 0.250 or higher. In addition, in the dielectric composition, an X-ray diffraction peak of a (410) plane of the tungsten bronze structure is splitted into two, and an integrated intensity ratio of an integrated intensity of a high-angle side peak of the X-ray diffraction peak with respect to an integrated intensity of a low-angle side peak of the X-ray diffraction peak is 0.125 or higher.

First brittle material particles; and second brittle material particles having smaller size than the first brittle material particles, wherein a void formed between the first brittle material particles is filled with at least one of the second brittle material particles, at a porosity of less than 20%.

Disclosed is a microcracked ceramic body, comprising a predominant phase (greater than 50 wt %) of zirconium tin titanate and a dilatometric coefficient of thermal expansion (CTE) from 25 to 1000 C of not more than 4010.sup.7 C..sup.1 as measured by dilatometry and methods for the manufacture of the same.