Piezoelectric ceramic for temperature controller and preparation method thereof

Abstract

The present invention relates to the field of piezoelectric ceramic materials, in particular to a piezoelectric ceramic for a temperature controller and a preparation method thereof, the chemical structure of which is as follows: (1-x-y)(Li α K β Na 1‑α‑β )Nb γ Sb 1‑γ O3‑xA(Sn ω Ti 1‑ω )O3-yCuMoO4, wherein x, y, α, β, γ, and ω are molar ratios; A is an alkaline earth metal; x is 0.05-0.2, y is 0.001-0.01; α is 0.01-0.15, β is 0.25-0.6, γ is 0.85-0.99, and ω is 0.01-0.1. The piezoelectric ceramics prepared by the present invention have excellent piezoelectric properties, and by comparison, A(Sn ω Ti 1‑ω The addition of CuO3 and CuMoO4 plays a positive role in improving the piezoelectric properties of piezoelectric ceramics.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric ceramic materials, in particular to a piezoelectric ceramic for a temperature controller and a preparation method thereof. Background Art

[0002] Piezoelectric ceramics can realize the mutual conversion between mechanical energy and electrical energy. They are an important type of functional ceramic material and are widely used in thermostats. KNN piezoelectric ceramics have a low density and a high Curie temperature. They are considered to be a promising type of lead-free piezoelectric ceramics to replace lead-based piezoelectric ceramics. However, the piezoelectric properties of pure KNN ceramics prepared by traditional solid-phase reaction method are very poor. At present, there are also many studies trying to compound KNN piezoelectric ceramics with other components to form multi-component piezoelectric ceramics or by adding sintering aids to reduce the sintering temperature and promote sintering, but the general effect is not very ideal. Summary of the Invention

[0003] Purpose of the invention: In order to solve the above technical problems, the present invention proposes a piezoelectric ceramic for a temperature controller and a preparation method thereof.

[0004] The technical solutions adopted are as follows:

[0005] A piezoelectric ceramic for a temperature controller, its chemical structure is as follows:

[0006] (1-xy)(Li α K β Na 1-α-β )Nb γ Sb 1-γ O3-xA(Sn ω Ti 1-ω )O3-yCuMoO4

[0007] Wherein, x, y, α, β, γ, and ω are molar ratios;

[0008] A is an alkaline earth metal;

[0009] x is 0.05-0.2, y is 0.001-0.01;

[0010] α is 0.01-0.15, β is 0.25-0.6, γ is 0.85-0.99, and ω is 0.01-0.1.

[0011] Furthermore, A is Sr and Ba.

[0012] Furthermore, the molar ratio of Sr to Ba is 1:3-6.

[0013] Furthermore, x is 0.08-0.15, and y is 0.003-0.006.

[0014] Furthermore, x is 0.1 and y is 0.005.

[0015] Furthermore, α is 0.02-0.1, β is 0.3-0.5, γ is 0.9-0.95, and ω is 0.03-0.08.

[0016] Furthermore, α is 0.05, β is 0.45, γ is 0.95, and ω is 0.06.

[0017] The present invention also provides a method for preparing piezoelectric ceramics for a temperature controller, which is as follows:

[0018] S1: Weigh AO, SnO2, and TiO2 according to the stoichiometric ratio, mix and grind, dry, and pre-calcine to obtain A(Sn ω Ti 1-ω ) O3 calcined body;

[0019] S2: Combine Li2CO3, Na2CO3, K2CO3, Nb2O5, Sb2O3, A(Sn ω Ti 1-ω )O3 pre-calcined body and CuMoO4 are mixed and ball-milled, dried, added with a binder to form granules, pressed into a green body, heated to 600-700℃ for debinding for 1-3h, then heated to 1150-1250℃ for sintering for 2-4h, cooled naturally to room temperature, polished, silvered, silver-burned, and polarized.

[0020] Furthermore, the pre-firing temperature in S1 is 950-1000°C.

[0021] Furthermore, the pressing pressure in S2 is 50-250 MPa.

[0022] Beneficial effects of the present invention:

[0023] The present invention provides a piezoelectric ceramic for a temperature controller, A(Sn ω Ti 1-ω )O3 as an ABO3 type additive, after the introduction of the multi-phase coexistence of polycrystalline phase boundary, resulting in domain wall movement and electric domain reversal easier under the external electric field, so that the piezoelectric performance can be enhanced. The addition of an appropriate amount of CuMoO4 can reduce the sintering temperature, increase the grain size, and improve the density of the ceramic. At the same time, Cu 2+ It preferentially occupies the B site of the perovskite structure, generates oxygen vacancies, forms "hard doping", and improves the piezoelectric performance. The piezoelectric ceramics prepared by the present invention have excellent piezoelectric performance, and by comparison, it can be seen that A(Sn ω Ti 1-ω The addition of CuMoO3 and CuMoO4 plays a positive role in improving the piezoelectric properties of piezoelectric ceramics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the SEM image of the piezoelectric ceramic prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.

[0026] Example 1:

[0027] A piezoelectric ceramic for temperature controller, its chemical structure is as follows: 0.895 (Li 0.05 K 0.45 Na 0.5 )Nb 0.95 Sb 0.05 O3-0.1Sr 0.2 Ba 0.8 (Sn 0.06 Ti 0.94 )O3-0.005CuMoO4

[0028] The preparation method of the piezoelectric ceramic for the temperature controller is as follows:

[0029] S1: SrO, BaO, SnO2, and TiO2 were weighed according to the stoichiometric ratio, added into a planetary ball mill with ethanol as the ball milling medium, and milled for 10 hours, then dried, and then heated to 980℃ and pre-calcined for 3 hours to obtain SrO2. 0.2 Ba 0.8 (Sn 0.06 Ti 0.94 ) O3 calcined body;

[0030] S2: Combine Li2CO3, Na2CO3, K2CO3, Nb2O5, Sb2O3, Sr 0.2 Ba 0.8 (Sn 0.06 Ti 0.94 )O3 pre-calcined body and CuMoO4 are added into a planetary ball mill with ethanol as the ball milling medium, mixed and ball-milled for 10 hours and then dried, 5% PVA is added as a binder to granulate, and the green body is pressed under a pressure of 100 MPa, and then heated to 650℃ for debinding for 2 hours, and then heated to 1200℃ for sintering for 3 hours. After naturally cooling to room temperature, it is polished with 600 mesh sandpaper, silvered, silver-sintered (580℃, 10 minutes), and an electric field of 3.5kV / mm is applied. The green body is kept warm and polarized in a 120℃ oil bath for 30 minutes, and then left for 24 hours.

[0031] Example 2:

[0032] A piezoelectric ceramic for temperature controller, its chemical structure is as follows: 0.895 (Li 0.05 K 0.45 Na 0.5 )Nb 0.95 Sb 0.05 O3-0.1Sr(Sn 0.06 Ti 0.94 )O3-0.005CuMoO4

[0033] The preparation method of the piezoelectric ceramic for the temperature controller is as follows:

[0034] S1: SrO, SnO2, and TiO2 were weighed according to the stoichiometric ratio, added into a planetary ball mill with ethanol as the ball milling medium, and milled for 10 hours, then dried, and then heated to 980℃ and pre-calcined for 3 hours to obtain Sr(Sn 0.06 Ti 0.94 ) O3 calcined body;

[0035] S2: Combine Li2CO3, Na2CO3, K2CO3, Nb2O5, Sb2O3, Sr(Sn 0.06 Ti 0.94 )O3 pre-calcined body and CuMoO4 are added into a planetary ball mill with ethanol as the ball milling medium, mixed and ball-milled for 10 hours and then dried, 5% PVA is added as a binder to granulate, and the green body is pressed under a pressure of 100 MPa, and then heated to 650℃ for debinding for 2 hours, and then heated to 1200℃ for sintering for 3 hours. After naturally cooling to room temperature, it is polished with 600 mesh sandpaper, silvered, silver-sintered (580℃, 10 minutes), and an electric field of 3.5kV / mm is applied. The green body is kept warm and polarized in a 120℃ oil bath for 30 minutes, and then left for 24 hours.

[0036] Example 3:

[0037] A piezoelectric ceramic for temperature controller, its chemical structure is as follows: 0.895 (Li 0.05 K 0.45 Na 0.5 )Nb 0.95 Sb 0.05 O3-0.1Ba(Sn 0.06 Ti 0.94 )O3-0.005CuMoO4

[0038] The preparation method of the piezoelectric ceramic for the temperature controller is as follows:

[0039] S1: BaO, SnO2, and TiO2 were weighed in a stoichiometric ratio, added to a planetary ball mill, and milled for 10 h using ethanol as the milling medium. The mixture was then dried and heated to 980°C for 3 h to obtain Ba(Sn 0.06 Ti 0.94 ) O3 calcined body;

[0040] S2: Combine Li2CO3, Na2CO3, K2CO3, Nb2O5, Sb2O3, Ba(Sn 0.06 Ti 0.94 )O3 pre-calcined body and CuMoO4 are added into a planetary ball mill with ethanol as the ball milling medium, mixed and ball-milled for 10 hours and then dried, 5% PVA is added as a binder to granulate, and the green body is pressed under a pressure of 100 MPa, and then heated to 650℃ for debinding for 2 hours, and then heated to 1200℃ for sintering for 3 hours. After naturally cooling to room temperature, it is polished with 600 mesh sandpaper, silvered, silver-sintered (580℃, 10 minutes), and an electric field of 3.5kV / mm is applied. The green body is kept warm and polarized in a 120℃ oil bath for 30 minutes, and then left for 24 hours.

[0041] Comparative Example 1:

[0042] The process is basically the same as Example 1, except that CuMoO4 is not added.

[0043] Comparative Example 2:

[0044] The same as Example 1, except that Sr is not added. 0.2 Ba 0.8 (Sn 0.06 Ti 0.94 )O3.

[0045] Performance testing:

[0046] The piezoelectric ceramics prepared in Examples 1-3 of the present invention and Comparative Examples 1-3 were used as samples for electrochemical performance tests. The test results are shown in Table 1 below:

[0047] Table 1:

[0048]

[0049] As can be seen from Table 1 above, the piezoelectric ceramics prepared by the present invention have excellent piezoelectric properties, and by comparison, it can be seen that Sr 0.2 Ba 0.8 (Sn 0.06 Ti 0.94 The addition of CuMoO3 and CuMoO4 plays a positive role in improving the piezoelectric properties of piezoelectric ceramics.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A piezoelectric ceramic for a temperature controller, characterized in that: Its chemical structure is shown below: (1-xy)(Li α K β Is 1-α-β )Nb γ Sb 1-γ O3-xA(Sn ω Built 1-ω )O3-yCuMoO4 Wherein, x, y, α, β, γ, ω are molar ratios; A is Sr and Ba, and the molar ratio of Sr to Ba is 1:3-6; x is 0.1, y is 0.005; α is 0.05, β is 0.45, γ is 0.95, and ω is 0.06; The preparation method of the piezoelectric ceramic for the temperature controller is as follows: S1: Weigh AO, SnO2, and TiO2 according to the stoichiometric ratio, mix and grind, dry, and pre-calcine to obtain A (Sn ω Ti 1-ω ) O3 pre-calcined body; S2: Combine Li2CO3, Na2CO3, K2CO3, Nb2O5, Sb2O3, A(Sn ω Ti 1-ω )O3 pre-calcined body and CuMoO4 are mixed and ball-milled and dried, a binder is added to granulate, pressed into a green body, heated to 600-700℃ for debinding for 1-3h, then heated to 1150-1250℃ for sintering for 2-4h, naturally cooled to room temperature, polished, silvered, silver-burned, and polarized; The pre-burning temperature in S1 is 950-1000°C; The pressing pressure in S2 is 50-250MPa.

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