High-Temperature Multilayer Piezoelectric Actuator Piezoelectric Ceramic Sheet and Its Preparation Method

Abstract

This invention discloses a piezoelectric ceramic sheet for a high-temperature multilayer piezoelectric actuator and its preparation method, belonging to the field of piezoelectric ceramic sheets and their preparation methods; the chemical formula of the piezoelectric ceramic material provided by this invention is: Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 The preparation method provided by this invention is as follows: O3 + 2wt% Li2CO3 + 0.1wt% CuO + 0.5wt% Bi2O3 + 0.5wt% Li2CO3; The raw materials are mixed according to the chemical formula, then ball-milled, dried, pre-fired, ball-milled again, dried, pressed into shape, sintered, printed with silver paste, calcined with silver, and polarized. The piezoelectric ceramic sheet provided by this invention has excellent piezoelectric properties while also reducing the sintering temperature and decreasing PbO volatilization. Furthermore, the piezoelectric ceramic sheet exhibits large deformation displacement and good stability, meeting the requirements for high-temperature multilayer piezoelectric actuators.

Description

Technical Field

[0001] This invention relates to a piezoelectric ceramic sheet and its preparation method, and more particularly to a high-temperature multilayer piezoelectric actuator and its preparation method; belonging to the field of piezoelectric ceramic technology. Background Technology

[0002] Low-temperature co-fired piezoelectric actuators are composed of alternating stacks of ceramic thin films and electrodes. During fabrication, due to the relatively low melting point of silver, excessively high sintering temperatures can promote the diffusion of silver atoms within the ceramic, leading to increased leakage current. Therefore, how to fabricate high-temperature piezoelectric ceramic materials using low-temperature junction technology is currently a significant research hotspot in the ceramics field.

[0003] To date, research on sintered multilayer piezoelectric ceramics has mainly focused on the composition of PZT-based ceramics, primarily due to their superior piezoelectric properties. Currently, three methods are commonly used to lower the sintering temperature. First, chemical synthesis using the sol-gel method yields ultrafine active PZT powder with high surface properties, increasing the driving force for grain growth. Second, high-pressure sintering effectively removes pores in the ceramic, increasing density and thus lowering the sintering temperature and improving piezoelectric properties. Third, low-temperature sintering aids are added to the ceramic. Many low-melting-point glassy phases form along grain boundaries, promoting grain growth and densifying the ceramic. Furthermore, the sintering aids replace Pb in the perovskite solid solution. 2+ or Ti 4+ The presence of this site increases structural defects, which is beneficial for atomic diffusion and improved electrical properties. Summary of the Invention

[0004] To address the aforementioned deficiencies in the prior art, this invention aims to provide a high-temperature multilayer piezoelectric actuator that can reduce sintering temperature and PbO volatilization without compromising piezoelectric performance; another objective of this invention is to provide a method for preparing the high-temperature multilayer piezoelectric actuator piezoelectric ceramic sheet.

[0005] To achieve the above objectives, the piezoelectric ceramic sheet provided by this invention has the following chemical formula: Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 O3+2wt%Li2CO3+0.1wt%CuO+0.5wt% Bi2O3+0.5wt% Li2CO3.

[0006] To prepare the piezoelectric ceramic sheet for the above-mentioned high-temperature multilayer piezoelectric actuator, the present invention employs the following method: 1) According to the chemical formula Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 O3 + 2wt%Li2CO3 The stoichiometric ratio of +0.1wt%CuO+0.5wt%Bi2O3+0.5wt%Li2CO3 is as follows: Weigh the raw materials Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Li2CO3, Bi2O3, and CuO, and divide Li2CO3 into group A and group B materials in a mass ratio of 4:1. 2) Mix the raw materials Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Bi2O3, and CuO with the materials in group A, ball mill for 4 hours, and dry to obtain the abrasive. 3) The abrasive is calcined in a sealed environment at 920°C for 2 hours to obtain pre-calcined material; 4) Mix the pre-fired material with the material in group B, ball mill for 8 hours, dry, and pass through a 40-mesh sieve to obtain ceramic powder; 5) Add polyvinyl alcohol to the ceramic powder, mix, granulate, and press into sheets to obtain a ceramic blank; the amount of polyvinyl alcohol added is 5% of the weight of the ceramic powder; 6) The ceramic blank is fed into a sintering furnace, heated to 600°C, and the binder is removed for 1 hour. Then the temperature is raised to 1100-1120°C and sintered for 4 hours to obtain ceramic slabs. 7) The ceramic tile is printed with silver paste, and then fired at 750°C to obtain a silver-plated ceramic tile; 8) The silver-coated ceramic sheet was placed in silicone oil at 80°C for 25 minutes to polarize it, with a polarization electric field strength of 3.5 kV / mm.

[0007] Compared with the prior art, the method of the present invention, by adopting the above-mentioned technical solution, can generate a liquid phase in the ceramic during the sintering process by adjusting the ratio of trace element doping and lead, zirconium and titanium, as well as adding an appropriate amount of sintering aid, which promotes grain growth (appropriate sintering aid will promote the growth of ceramic grains; too much or too little will lead to non-dense sintering or reduced electrical properties). Therefore, the piezoelectric ceramic sheet prepared has excellent piezoelectric properties while also reducing the sintering temperature and reducing the volatilization of PbO. In addition, the piezoelectric ceramic sheet has a large deformation displacement and good stability.

[0008] The following is a performance comparison of piezoelectric ceramic sheets for high-temperature multilayer piezoelectric actuators prepared by the method of this invention with piezoelectric ceramic sheets prepared by conventional methods.

[0009] Table 1: Comparison of performance parameters of piezoelectric ceramics prepared by the method of the present invention and piezoelectric ceramics prepared by conventional methods

[0010] The performance of the ceramic powder before and after the improvement is very similar, but the sintering temperature is reduced by nearly 170°C and the Curie temperature is reduced by only 3°C, making it very suitable for high-temperature applications in piezoelectric actuators. Attached Figure Description

[0011] Figure 1 This is a microscopic morphology image of the piezoelectric ceramic sheet powder for high-temperature stacked piezoelectric actuators provided by the present invention; Figure 2 This is a SEM image of the piezoelectric ceramic sheet for the high-temperature multilayer piezoelectric actuator provided by the present invention. Detailed Implementation

[0012] The present invention will be further described below with reference to specific embodiments: Example

[0013] 1) According to the chemical formula Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 O3 + 2wt% Li2CO3 The stoichiometric ratio of +0.1wt% CuO +0.5wt% Bi2O3 +0.5wt% Li2CO3 is as follows: Weigh the raw materials Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Li2CO3, Bi2O3, and CuO, and divide Li2CO3 into group A and group B materials in a mass ratio of 4:1. 2) Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Bi2O3, CuO and group A materials were mixed, ball-milled for 4 hours, and dried to obtain abrasive; wherein, the ratio of zirconium balls:material:deionized water was 2:1:1, and the rotation speed was 460 r / min. 3) Place the abrasive into a sealed crucible, heat it to 920°C at a rate of 2°C / min, hold it at that temperature for 2 hours, and then cool it in the furnace to obtain the pre-burned material; 4) Mix the pre-fired material with the material in group B, ball mill for 8 hours, dry, and pass through a 40-mesh sieve to obtain ceramic powder; wherein, the ratio of zirconium balls:material:deionized water is 2:1:0.6, and the rotation speed is 460 r / min; 5) Add polyvinyl alcohol to the ceramic powder, mix, granulate, and press into ceramic blanks with a diameter of Φ10×1mm; the amount of polyvinyl alcohol added is 5% of the weight of the ceramic powder; 6) The ceramic blank is fed into a sintering furnace and heated to 600°C at a rate of 1°C / min. The binder is removed for 1 hour, and then heated to 1100-1120°C at a rate of 2°C / min. The blank is sintered for 4 hours and then cooled in the furnace to obtain ceramic slabs. 7) The ceramic sheet is printed with silver paste, then heated to 750°C at a rate of 3°C / min, held for 20 minutes, and cooled in the furnace to obtain silver-coated ceramic sheets. 8) The silver-coated ceramic sheet was placed in silicone oil at 80°C for 25 minutes to polarize it, with a polarization electric field strength of 3.5 kV / mm.

[0014] from Figures 1-2 It can be seen that the powder after ball milling has a uniform particle size, which ensures the consistency of the powder.

Claims

1. A method for preparing a piezoelectric ceramic sheet for a high-temperature multilayer piezoelectric actuator, characterized in that... The steps are as follows: 1) According to the chemical formula Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 The stoichiometric ratio of O3+2wt% Li2CO3+0.1wt% CuO+0.5wt% Bi2O3+0.5wt% Li2CO3 is as follows: Weigh the raw materials Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Li2CO3, Bi2O3, and CuO, and divide Li2CO3 into group A and group B materials in a mass ratio of 4:

1. 2) Mix the raw materials Pb3O4, SrCO3, Sb2O3, Nb2O5, NiO, Bi2O3, and CuO with the materials in group A, ball mill for 4 hours, and dry to obtain the abrasive. 3) The abrasive is calcined in a sealed environment at 920°C for 2 hours to obtain pre-calcined material; 4) Mix the pre-fired material with the material in group B, ball mill for 8 hours, dry, and pass through a 40-mesh sieve to obtain ceramic powder; 5) Add polyvinyl alcohol to the ceramic powder, mix, granulate, and press into sheets to obtain a ceramic blank; the amount of polyvinyl alcohol added is 5% of the weight of the ceramic powder; 6) The ceramic blank is fed into a sintering furnace, heated to 600°C, and the binder is removed for 1 hour. Then the temperature is raised to 1100-1120°C and sintered for 4 hours to obtain ceramic slabs. 7) The ceramic tile is printed with silver paste, and then fired at 750°C to obtain a silver-plated ceramic tile; 8) The silver-coated ceramic sheet was placed in silicone oil at 80°C for 25 minutes to polarize it, with a polarization electric field strength of 3.5 kV / mm.

2. A piezoelectric ceramic sheet for a high-temperature multilayer piezoelectric actuator prepared according to the method of claim 1, characterized in that... The chemical formula of the piezoelectric ceramic sheet used in the high-temperature multilayer piezoelectric actuator is: Pb 0.97 Sr 0.03 (Sb 1 / 3 Nb 2 / 3 ) 0.3 (Ni 1 / 3 Nb 2 / 3 ) 0.7 O3+2wt% Li2CO3+0.1wt% CuO+0.5wt% Bi2O3+0.5wt% Li2CO3.

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