CN-122003096-A - Piezoelectric composite material with reinforced electrode and preparation method thereof

CN122003096ACN 122003096 ACN122003096 ACN 122003096ACN-122003096-A

Abstract

The invention relates to a piezoelectric composite material with reinforced electrodes and a preparation method thereof, comprising the following steps: the piezoelectric ceramic device comprises a piezoelectric ceramic array, an upper reinforcing electrode and a lower reinforcing electrode which are respectively positioned on the upper surface and the lower surface of the piezoelectric ceramic array, and a polymer filled in gaps among the upper reinforcing electrode, the piezoelectric ceramic array and the lower reinforcing electrode. The invention fundamentally improves the mechanical strength, the wear resistance and the welding reliability of the electrode, provides effective protection and mechanical locking for the piezoelectric ceramic column, and remarkably improves the structural integrity, the processing yield and the long-term stability of the product.

Inventors

XIE XIANHUI
YU SHAOXIANG
Yu Kangshu
LIU PENG
WANG CONG
XU YUN
SHEN JIAQIANG

Assignees

中国船舶集团有限公司第七一五研究所

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. The piezoelectric composite material with the reinforced electrodes is characterized by comprising a piezoelectric ceramic array, an upper reinforced electrode, a lower reinforced electrode and a polymer, wherein the upper reinforced electrode and the lower reinforced electrode are respectively arranged on the upper surface and the lower surface of the piezoelectric ceramic array, and the polymer is filled in gaps among the upper reinforced electrode, the piezoelectric ceramic array and the lower reinforced electrode; The upper reinforcing electrode penetrates through and is electrically connected with the piezoelectric vibrators arranged along the first direction, and the lower reinforcing electrode penetrates through and is electrically connected with the piezoelectric vibrators arranged along the second direction intersecting the first direction.
2. The piezoelectric composite material with reinforcing electrode according to claim 1, wherein the upper reinforcing electrode and the lower reinforcing electrode are soldered to the piezoelectric vibrator by a solder having a melting point lower than the curie temperature of the piezoelectric ceramic.
3. The piezoelectric composite with reinforced electrodes of claim 1, wherein the polymer is selected from polyurethane, epoxy, polydimethylsiloxane, or acrylic.
4. The piezoelectric composite material with reinforced electrodes according to claim 1, wherein the upper reinforced electrode and the lower reinforced electrode are made of conductive metal materials.
5. The piezoelectric composite with enhanced electrode according to claim 1, wherein each piezoelectric vibrator in the piezoelectric ceramic array is physically completely separated from each other, and the polymer fills in gaps between all adjacent piezoelectric vibrators.
6. The piezoelectric composite with reinforcing electrodes according to claim 1, wherein the upper reinforcing electrode and the lower reinforcing electrode together form a reinforcing electrode grid structure supporting and mechanically locking the piezoelectric ceramic array.
7. The piezoelectric composite material with reinforced electrode according to claim 1, wherein an additional conductive layer for external circuit connection is further provided on the outer surface of the upper and/or lower reinforced electrode, and the additional conductive layer is attached by bonding, soldering or printing.
8. The piezoelectric composite with enhanced electrode according to claim 1, wherein the piezoelectric vibrator is a piezoelectric ceramic post.
9. A method of preparing a piezoelectric composite having a reinforced electrode according to any one of claims 1 to 8, comprising the steps of: Providing a polarized piezoelectric ceramic substrate; Welding metal electrode plates on the upper surface and the lower surface of the piezoelectric ceramic substrate respectively by using welding materials to form a composite precursor; Cutting the composite precursor for the first time along the first direction, wherein the cutting depth is at least cut through the upper metal electrode plate and the piezoelectric ceramic layer bonded with the upper metal electrode plate; turning over the composite precursor, and performing secondary cutting along a second direction intersecting with the first direction, wherein the cutting depth is at least cut through the upper metal electrode plate and the piezoelectric ceramic layer bonded with the upper metal electrode plate, so as to form a piezoelectric ceramic array intermediate supported and connected by the metal electrode plate; And pouring a polymer precursor into a gap of the piezoelectric ceramic array intermediate, and solidifying the polymer precursor to obtain the piezoelectric composite material.
10. The method of claim 9, wherein the first and second cuts are each of a depth that ensures complete severing of the piezoceramic substrate, and wherein the piezoceramic array intermediate is held in place using a clamp prior to or during the infusion of the polymer precursor.

Description

Piezoelectric composite material with reinforced electrode and preparation method thereof Technical Field The invention belongs to the technical field of piezoelectric materials, and particularly relates to a piezoelectric composite material with reinforced electrodes and a preparation method thereof. Background The piezoelectric composite material is widely applied to the fields of medical ultrasonic imaging, underwater sonar, structural health monitoring, precise driving and the like due to excellent electromechanical conversion performance and design flexibility. The 1-3 type piezoelectric composite material consists of piezoelectric ceramic columns arranged along the thickness direction and polymer phases filled between the columns, has a good thickness vibration mode and lower acoustic impedance, and becomes a core material of the high-performance piezoelectric transducer. The 1-3 type piezoelectric composite material is generally composed of independent PZT piezoelectric ceramic columns or fibers which are arranged in parallel along the polarization direction and are filled with polymers at intervals, wherein 1 generally represents a one-dimensional piezoelectric small column, and 3 represents a three-dimensional communicated polymer phase. The structure can effectively weaken the coupling of the deformation of the piezoelectric ceramics in the polarization direction and the non-polarization direction. The existing methods for preparing the 1-3 type piezoelectric composite material comprise an arrangement pouring method, a cutting filling method, an injection molding method and the like, wherein the cutting filling method is more suitable for large-scale production of medium-small-size composite materials compared with other methods, and the method is widely applied. The structure of the dicing and filling method is schematically shown in fig. 5, and the square piezoelectric pillars of the dicing and filling method are exemplified by a pillar thickness t, a pillar width pw, and a pillar pitch ew. The polarized piezoelectric units vibrate longitudinally under the excitation of an electric field, and the polymer phase can greatly reduce the coupling effect among the units caused by the poisson effect, so that the 1-3 type piezoelectric composite material has a purer thickness vibration mode and improves the effective electromechanical coupling coefficient kt. Meanwhile, the acoustic impedance of the piezoelectric composite material is reduced due to low characteristic impedance of the polymer phase. However, the method forms a regular piezoelectric ceramic array by adding a sacrificial layer or reserving a ceramic substrate with a part not cut off, and removes the part outside the ceramic array by polishing after pouring, thereby removing the sintered electrode on the surface of the original piezoelectric ceramic. Due to the presence of the polymer, sintering cannot be performed again, and the electrode can only be attached again by means of printing, magnetron sputtering, or the like. The electrode layer prepared by the method has much lower peeling strength than a sintered electrode, and is easy to crack, separate out or peel off in the processing and welding processes. Meanwhile, the traditional electrode can not provide effective support for the brittle piezoelectric ceramic, so that the stress can not be effectively controlled in the cutting process, and ceramic edge breakage or ceramic matrix interval deviation is very easy to occur. Although technological innovation is tried in the prior art, as described in chinese patent publication No. cn107170882.a, a 1-3 type piezoelectric composite material based on improved polymer phase and a preparation method thereof, polymer is filled in gaps of a piezoelectric ceramic array in layers by a fractional filling manner, so that polymer filling layers near two ends of an end face of the piezoelectric ceramic have different young's moduli from polymer filling layers near a central portion of the piezoelectric ceramic. The chinese patent publication No. cn103456878.A makes the piezoelectric ceramic array have a non-uniform period (the substrate is retained, and the electrode is coated after the whole is ground) by adjusting the cutting pitch. And the patent application with the Chinese patent publication number of CN116973458.A forms a stable piezoelectric ceramic array by cutting without cutting twice and polishing after filling twice. But the problems that the mechanical strength of the electrode is insufficient and the ceramic column is easily damaged in the processing process are not fundamentally solved. Therefore, development of a novel piezoelectric composite structure and a preparation method thereof are needed, which can provide powerful mechanical support and protection for brittle piezoelectric ceramic columns while maintaining high-adhesion electrodes, simplify the process flow and improve the reliability, yield and comprehensive performance of pr