High-density fine-grained piezoelectric ceramic for high-power device applications and method for manufacturing the same

Abstract

A high-density fine-grained piezoelectric ceramic for high-power device applications and a preparation method thereof belong to the technical field of piezoelectric ceramics. The chemical composition is: Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-xwt.%MnCO3, 0.2

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric ceramics technology, specifically relating to a lead zirconate titanate (PZT)-based high-density fine-grained piezoelectric ceramic and its preparation method. Background Technology

[0002] Piezoelectric ceramics, due to their excellent electromechanical conversion properties, are widely used in high-power devices such as transformers, transducers, and ultrasonic motors. To achieve high power output characteristics, piezoelectric ceramic materials for high-power device applications typically require a high piezoelectric constant (d). 33 Mechanical quality factor (Q) m and a high power quality factor (k p 2 ·Q m The parameters mentioned above are typically determined using an impedance analyzer at low voltage (1V); however, high-power piezoelectric devices require high voltage to achieve higher deformation or force during actual operation. Therefore, at the resonant frequency f... r The maximum vibration velocity v achievable by a piezoelectric ceramic driven by a pulsed voltage (300V) in the vicinity becomes an important parameter for evaluating high-power performance. i With electric field E j The relationship between the piezoelectric performance parameters is as follows:

[0003]

[0004] In the formula, ε ij k is the dielectric constant. ij ρ is the electromechanical coupling coefficient, ρ is the density, and d is the electromechanical coupling coefficient. ij It is the piezoelectric constant. This is the compliance coefficient.

[0005] To meet the high d requirements of high-power piezoelectric ceramics 33 Q m k p 2 ·Q m In response to the requirement of high vibration velocity v, this patent proposes a comprehensive method to obtain PZT ceramics that meet high power requirements through A- and B-site co-doping combined with ceramic density control. First, equivalent doping at the A-site can achieve high piezoelectric properties; second, oxygen vacancies pinning domain walls at the B-site caused by the main doping can achieve a high mechanical quality factor; fine grains and high density help reduce ceramic losses under high fields. Summary of the Invention

[0006] This invention prepares a ceramic material with a high voltage constant d by co-doping at A and B sites combined with ceramic compactness control. 33 High mechanical quality factor Q m High power quality factor kp 2 ·Q m and fine-grained PZT-based piezoelectric ceramics with high vibration velocity v characteristics.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The chemical composition of the piezoelectric ceramic is: Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3 - x wt. % MnCO3, 0.2 < x < 0.6 (abbreviated as PBZT - xMn), relative density > 98%, grain size < 2.1 μm.

[0009] The preparation method of the above PBZT - xMn ceramic with high - power characteristics specifically includes the following steps:

[0010] (1) Synthesize PBZT - xMn ceramic powder through solid - state reaction; first, put the raw materials Pb3O4, BaCO3, TiO2, ZrO2, MnCO3 into an oven and dry at 120 °C for 12 hours, and then weigh according to the stoichiometric ratio;

[0011] (2) Ball - mill for 12 hours with anhydrous ethanol as the medium through a planetary ball mill, and then dry at 100 °C; put the dried powder into a mortar for grinding, then put the powder into a crucible and calcine at 850 °C for 2 hours, ball - mill the calcined powder again for 24 hours and dry it, and obtain PBZT - xMn powder after grinding;

[0012] (3) After granulating and sieving the powder, press it into a sheet - shaped ceramic blank, and sinter the formed blank in a sintering furnace at 1275 °C under normal pressure for 3 - 9 hours to obtain PBZT - xMn ceramic;

[0013] The surface of the prepared ceramic is polished and buffed, ultrasonically cleaned, coated with silver electrodes on the ceramic surface and dried in an oven, then placed in a sintering furnace and calcined at 550 °C for 30 min. Finally, perform polarization treatment in an oil bath at 130 °C, polarization electric field 4 kV / mm, polarization time 30 min, age for 24 hours and then conduct electrical property tests.

[0014] The optimal process conditions for step (3) are: when x = 0.5, the ceramic is sintered at 1275 °C for 8 hours, its grain size is 1.93 μm, and the electrical properties are: d 33 = 270 pC / N, k p = 0.65, Q m = 836, k p 2 ·Q m=353, v=2.4m / s. Attached Figure Description

[0015] Figure 1 The XRD pattern of PBZT-0.5Mn piezoelectric ceramic.

[0016] Figure 2 This is a SEM image of a high-density, fine-grained PBZT-0.5Mn piezoelectric ceramic. Detailed Implementation

[0017] The essential features and significant advantages of the present invention are further illustrated below through examples. It should be noted that the present invention is by no means limited to the embodiments described.

[0018] The overall steps are as follows:

[0019] Specifically, the following steps are included:

[0020] (1) Synthesize PBZT-xMn ceramic powder by solid-state reaction; First, put the raw materials Pb3O4, BaCO3, TiO2, ZrO2 and MnCO3 into an oven and dry them at 120℃ for 12 hours, and then weigh them according to the stoichiometric ratio.

[0021] (2) The solid powder was ball-milled for 12 hours in a planetary ball mill with anhydrous ethanol as the medium, and then dried at 100°C. The dried solid powder was then ground in a mortar, and then the powder was placed in a crucible and calcined at 850°C for 2 hours. The calcined powder was ball-milled again for 24 hours and then dried. PBZT-xMn powder was obtained after grinding.

[0022] (3) After the powder is granulated and sieved, it is pressed into a circular ceramic blank of a specific size. The blank is sintered in a sintering furnace at 1275℃ and normal pressure for 3-9 hours to obtain PBZT-xMn ceramic.

[0023] The specific implementation methods differ.

[0024] Example 1:

[0025] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-0.3wt.%MnCO3(PBZT-0.3Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 3 hours.

[0026] Example 2:

[0027] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47O3-0.5wt.%MnCO3(PBZT-0.5Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 3 hours.

[0028] Example 3:

[0029] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-0.5wt.%MnCO3(PBZT-0.5Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 6 hours.

[0030] Example 4:

[0031] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-0.5wt.%MnCO3(PBZT-0.5Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 7 hours.

[0032] Example 5:

[0033] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-0.5wt.%MnCO3(PBZT-0.5Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 8 hours.

[0034] Example 6:

[0035] Synthesis of Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-0.5wt.%MnCO3(PBZT-0.5Mn) ceramic powder, the method is the same as steps (1) and (2), and the formed green body is sintered in a sintering furnace at 1275℃ for 9 hours.

[0036] Table 1 Performance Comparison of the Above Embodiments

[0037]

[0038] The above is at the resonant frequency f r The maximum vibration velocity v that can be achieved by a piezoelectric ceramic driven by a pulse voltage (300V) in the vicinity is a parameter used to evaluate high-power performance.

Claims

1. A high-density, fine-grained piezoelectric ceramic material for high-power applications, characterized in that, The chemical composition of this ceramic is: Pb 0.9 Ba 0.1 Zr 0.53 Ti 0.47 O3-xwt.%MnCO3, x =0.5, relative density >98%, grain size <2.1 μm; Preparation method, Includes the following steps: (1) First, put the raw materials Pb3O4, BaCO3, TiO2, ZrO2 and MnCO3 into an oven and dry them at 120 °C for 12 hours, and then weigh them according to the stoichiometric ratio; (2) The solid was ball-milled for 12 hours in a planetary ball mill with anhydrous ethanol as the medium, and then dried at 100°C. The dried sheet solid was then ground in a mortar, and the powder was then placed in a crucible and calcined at 850°C for 2 hours. The calcined powder was then ball-milled again for 24 hours and dried. (3) After the powder is granulated and sieved, it is pressed into a circular ceramic blank of a specific size. The blank is sintered in a sintering furnace at 1275℃ and normal pressure for 6-9 hours to obtain high-power PZT-based piezoelectric ceramic.

2. A high-density, fine-grained piezoelectric ceramic material for high-power applications according to claim 1, characterized in that, The ceramic was sintered at 1275℃ under normal pressure for 8 hours, resulting in a relative density of 99% and a grain size of 1.93 μm.

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