SU981295A1 - Piezoelectric ceramic material - Google Patents

Description

shallow. The initial components in the form of metal oxides (PbO, T 1 (1, ZrO) or their salts (VOCO 3)) weighed in the desired weight ratios are mixed using any method used in ceramic technology. Synthesis of the base material is carried out at t and duration 2 h in the furnace atmosphere, the temperature rise rate h. Sinter is ground, after which a separate addition of lanthanum ferrite is introduced according to the proposal. Lanthanum ferrite is prepared from lanthanum oxide and iron oxide by mixing them in certain weight The synthesis of the additive is carried out at a temperature and a shutter speed of 2 hours. Another method of manufacturing the proposed piezoceramic material is possible, in which the two operations for preparing the base composition and the additive of lanthanum ferrite are combined in one next U1 form. All the initial components necessary for preparing the base composition, so for the preparation of the added additive of lanthanum ferrite, taken in the proportions necessary for the preparation of the proposed composition and subjected to mixing by any known ceramic produced two ways (in a ball mill, or a vibrating mill). In the rest, the described technology is preserved. Measurements are made on samples with a diameter of 12 mm. The table shows the parameters of the optimal compositions of the proposed material and the material of the prototype. As can be seen from the table, the presented compositions of the proposed material have an increased piezomodule (195 and 190 C / H instead of 158 C / H of the prototype) as compared with the prototype at similar values of the dielectric constant. The proposed material has a significantly greater value of the coefficient of electromechanical-. in combination with a prototype (Cr 0.45), i.e. causes better energy conversion, and lower value. The sintering of the samples of the material proposed is carried out in an atmosphere of lead oxide at a temperature of 12401280 ° C. The samples are polarized in silicone oil at t 130150 ° C in a field of 2–3 kV / mm for 1 h, followed by cooling under a field. The best properties are obtained on the material, having the following chemical composition (Pbogig.1 La ,, / BaTiOj PbZrOj LaFeO, This material compared to the prototype, a higher value of modulus (cCh 195-10 C / N versus 15819 1СЛ / Н) and a lower value speed of sound (V 3180 m / s instead of V, 3490 m / s), which allows to obtain the best piezo properties on converters of this material while ensuring small wave sizes. The proposed material should be used both in radiators and receivers.

Table continuation

PbZrO, about the fact that, in order to improve the piezoelectric effect and decrease the speed of sound, it additionally contains L.aFeO with the following ratio of components, mol.%:

 24.05-44.41

Ptyu: BaTiOj 4.81-14.81

 Sources of information taken into account in the examination

40

1. Patent cum 2849404, cl. 252-62.9, 1958,

, 2, USSR author's certificate 252437, cl. From 04 to 35/46, 1967.

Claims (2)

SUMMARY OF THE INVENTION A piezoelectric ceramic material comprising PbTiO-, BaTi0 _3t PbZrOj, and ⁵ s with the fact that, in order to increase the piezoelectric effect and reduce the speed of sound, it additionally contains LaFeO ^ in the following ratio of molar components. %: PbTiO ₃ '24.05-44.41 BaTiOj 4.81-14.81 35 PbZrO ₃ 48.09-59.22 LaFeO ₃ 1.31-3.84 'Sources of information, 40 taken into account during the examination 1. US patent No. 2849404, CL. 252-62.9, 1958. 2. USSR copyright certificate No. 252437, cl. C 04 V 35/46, 1967.