A kind of lead zirconate titanate fine-grained piezoelectric ceramic with high electromechanical coupling performance and preparation method thereof

Abstract

The invention provides a lead zirconate titanate fine-grained piezoelectric ceramic with high electromechanical coupling performance, the molecular formula of which is Pb1-x-y-zBaxNbyNiz(ZraTi1-a)O3, wherein 0<x≤0.1, 0<y≤0.08, 0<z≤0.08, 0.51<a≤0.6. The invention obtains a modified high-performance piezoelectric ceramic by using barium, niobium and nickel to modify the lead zirconate titanate piezoelectric ceramic. Especially when Pb1‑x‑y‑zBaxNbyNiz(ZraTi1‑a)O3, the substitution amount x=0.06, y=0.05, z=0.03, a=0.55, and the synthesis reaction temperature is 850℃, the obtained modified piezoelectric The comprehensive piezoelectric performance of ceramics is the best, among which, the dielectric constant is 3600, the piezoelectric coefficient d33 is 620pC / N, the electromechanical coupling coefficient kp value is 80%, the dielectric loss is less than 1%, and the average grain size is controlled at 2‑4 microns , with excellent mechanical properties while maintaining high piezoelectric properties. Correspondingly, the invention also provides a preparation method of the fine-grained piezoelectric ceramic.

Description

technical field [0001] The invention relates to a piezoelectric ceramic material, in particular to a lead zirconate titanate fine-grain piezoelectric ceramic with high electromechanical coupling performance, and also relates to a preparation method of the fine-grain piezoelectric ceramic. Background technique [0002] Piezoelectric ceramics are made by high-temperature sintering. It is an emerging ceramic material with high dielectric constant, piezoelectricity and excellent electromechanical coupling performance, which can convert mechanical energy and electrical energy into each other. The most representative one is lead zirconate titanate (PZT) piezoelectric ceramics. Due to its piezoelectric properties and various dielectric properties caused by piezoelectricity, PZT piezoelectric ceramics are widely used in aerospace, electronics, computers, lasers, Applications such as ultrasound and energy are widely used. [0003] With the continuous development of various industrie...

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Problems solved by technology

[0005] Chinese patent CN201510179552.8 discloses a niobium nickel-lead zirconate titanate piezoelectric ceramic (PMN-PZT) doped with manganese lead antimonate, and obtains a chemical formula (1-x)Pb(Ni 1 / 3 Nb 2 / 3 ) 0.5 Zr y Ti 0.5-y o 3 -xPbMn 1 / 3 Sb 2 / 3 o 3 (where y=0.10~0.20, x=0~0.06) with high piezoelectric coefficient and excellent mechanical properties (E~120GPa, K 1C ~1.4MPa·m 1 / 2 ), but the electromechanical coupling coefficient of the piezoelectric ceramic is only 0.53, and the energy conversion efficiency is too low to meet the application requirements

[0006] Chinese patent CN200410016324.0 discloses a doped lead niobate manganate-lead zirconate titanate piezoelectric ceramic material and its preparation process. 3 Replace part of PbO and add MnCO 3 , obtained a piezoelectric ceramic material with a bending strength of 97MPa, a dielectric loss of less than 0.5%, and an electromechanical coupling coefficient of up to 0.59. The low electromechanical coupling coefficient makes the energy conversion efficiency too low in application, and cannot reach the application target. Require

[0007] In another master's degree thesis of Tianjin University, "Research on Low-loss PMS-PZT Piezoelectric Ceramic Materials", a composition of Pb 1.02 (Mn 1 / 3 Sb 2 / 3) x(Zr 0.47 Ti 0.48 ) (1-x) / 0.95 o 3 Ternary piezoelectric ceramics, the best piezoelectric coefficient d33 is 340pC / N, the mechanical quality factor kp=0.585, the relative dielectric constant is 1369, and the dielectric loss is 0.31%. The corresponding mechanical quality of the piezoelectric ceramic material The factor is 0.585, which is far from meeting the requirements of the application

[0008] Through the analysis of the existing technical documents, it is found that the lead zirconate titanate product has too large grains (7-12 microns), many pores, and the product is brittle and easy to crack during vibration work, resulting in unstable performance and affecting the quality of the product. Mechanical Properties and Reliability

The reliability of piezoelectric ceramic products can be greatly improved by adopting the method of refining grains (usually 2-4 microns), but usually this method will simultaneously reduce the piezoelectric properties of lead zirconate titanate (such as the dielectric constant εr and electromechanical coupling coefficient Kp, etc.)

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