Preparation method of special-shaped piezoelectric composite material

Abstract

The method for preparing a special-shaped piezoelectric composite material includes the following steps: a. Fixing a piezoelectric ceramic piece to a fixture and cutting the piezoelectric ceramic piece; b. After cutting, pouring epoxy into the piezoelectric ceramic piece and the fixture together, allowing the epoxy to enter the cutting seam; c. Removing the piezoelectric ceramic piece from the fixture and removing excess epoxy; d. Electrodes are formed on the outer wall of the piezoelectric ceramic piece by magnetron sputtering, vacuum evaporation or conductive adhesive. The present invention is used to solve the problems of difficult control of the positioning accuracy of seam cutting, easy breaking of piezoelectric crystal columns by bending of the die, difficulty in demolding after pouring the hard composite material, and difficulty in splicing the spherical shell.

Description

Technical Field

[0001] The invention relates to a method for preparing a special-shaped piezoelectric composite material. Background Art

[0002] The piezoelectric composite material is a composite material composed of a ceramic phase with piezoelectric function and a polymer phase connecting the ceramic phase according to a certain connectivity and formula ratio. It can not only give full play to the piezoelectric characteristics of the ceramic phase, but also make up for the defects of the ceramic phase itself such as high impedance and low flexibility. It is widely used in the fields of underwater sound and ultrasound. According to the connectivity between the piezoelectric phase and the polymer phase, the piezoelectric composite material is divided into 0-0, 0-1, 0-2, 0-3, 1-1, 1-2, 1-3 and other types. The present invention provides a manufacturing process of a 1-3 type special-shaped piezoelectric composite material.

[0003] There are many patents related to the preparation of piezoelectric composite materials, but after analysis of the literature, the problems to be solved by this patent are different. Specifically, the piezoelectric composite materials disclosed in patent documents CN1248558A, CN200410060685.5, CN200680020077.9, CN200710052452.4, CN200810140889.8, CN200910020658.8, CN200910059729.5, CN200910167647.2, CN200910167648.7, CN201010175156.5, etc. are 0-3 type. The piezoelectric composite materials disclosed in patent documents CN200910082788.4 and CN200710122237.7 are 3-0 type. The piezoelectric composite materials disclosed in patent documents CN200910078780.0 and CN100401545C are of type 1-3-2. The former document is characterized by the periodic difference in the height of the piezoelectric crystal column, which increases the bandwidth of the piezoelectric composite material. The latter document can be said to be the basic document for the preparation process of all 1-3-2 piezoelectric composite materials. The piezoelectric composite material disclosed in patent document CN200810067783.X is of type 3-1. The piezoelectric composite material disclosed in patent document CN200780052548.9 is of type 3-3. Patent document CN1788366A introduces a 2-2 composite material with any volume ratio formed by shifting and cutting opposite cross substrates, and the processing technology is relatively complicated. The piezoelectric composite material disclosed in patent document CN200810067783.X is of type 1-3 or type 2-2. The method used is to cut the front and back sides of the piezoelectric crystal to form a through piezoelectric composite material method, and the processing technology is relatively complicated. The shapes of the piezoelectric composite materials mentioned in all the above patent documents are generally simple, mainly flat-plate piezoelectric composite materials. This patent provides a preparation process for tubular and spherical shell 1-3 type piezoelectric composite materials.

[0004] The patent document closest to this patent is CN110191405B. This patent involves a method for preparing a spherical shell-shaped piezoelectric composite material: cutting the piezoelectric ceramic sheet on the positive side, filling with flexible polymer, cutting the ceramic substrate on the reverse side, bending the die, pouring hard polymer, demolding, fixing on the positioning tooling, grinding or cutting, coating the electrode, and splicing the spherical shell. The preparation process is complicated, and the problems are that the positioning accuracy of the reverse side seam cutting is difficult to control, the bending of the die is easy to break the piezoelectric crystal column, the hard composite is not easy to demold after pouring, and the difficulty of splicing the spherical shell is great. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing special-shaped piezoelectric composite materials, which is used to solve the problems that the positioning accuracy of seam cutting is difficult to control, the bending of the die is easy to break the piezoelectric crystal column, the hard composite material is difficult to demold after injection, and the difficulty of splicing the spherical shell is great.

[0006] In order to solve the above problems, the technical solution of the present invention is:

[0007] A method for preparing a special-shaped piezoelectric composite material comprises the following steps:

[0008] a. Fix the piezoelectric ceramic piece to the fixture and cut the piezoelectric ceramic piece;

[0009] b. After cutting, pour epoxy into the piezoelectric ceramic and the fixture together, and let the epoxy enter the cutting seam;

[0010] c. Remove the piezoelectric ceramic from the fixture and remove excess epoxy;

[0011] d. Use magnetron sputtering, vacuum evaporation or conductive adhesive to form electrodes on the outer wall of the piezoelectric ceramic component.

[0012] The piezoelectric ceramic piece is a round tube, the fixture comprises a bracket and a core rod assembled in the round tube, the core rod is rotatably connected to the bracket through a rotating shaft, a first pin hole is provided on the bracket, a first indexing pin is provided in the first pin hole, a plurality of first plug holes are provided on the surface of the core rod, each first plug hole is evenly distributed around the axis of the rotating shaft, and the first indexing pin is inserted into the first plug hole;

[0013] The preparation method of the circular tube piezoelectric composite material is as follows:

[0014] a. Then bond the round tube to the mandrel, and then use a cutting machine to axially cut the round tube. Each time a slit is cut on the round tube, the round tube is rotated by an angle, and the first indexing pin is inserted into the first insertion hole corresponding to the angle, and then the round tube is axially cut again, and this is repeated until the remaining cutting seams are cut;

[0015] It also includes a branch pipe block, one side of which is provided with an arc-shaped notch for placing a circular pipe;

[0016] b. After the cutting seam on the round tube is cut, place the round tube and the mandrel into the arc-shaped notch of the branch block, and perform circumferential cutting on the round tube. After the circumferential cutting is completed, inject epoxy into the mandrel and the round tube together, and allow the epoxy to enter the cutting seam on the round tube;

[0017] c. After the epoxy is cured, remove the tube from the mandrel and machine the outer wall of the tube to remove excess epoxy.

[0018] d. Use magnetron sputtering, vacuum evaporation or conductive adhesive to apply electrodes to the circular tube.

[0019] The piezoelectric ceramic part is a spherical shell, and the fixture includes a fixing plate, which is connected to a base, one end of the base has a ball head, a joint pin is mounted on the ball head, a ball holder sleeved on the ball head is connected to the joint pin, one end of the ball holder is connected to a dividing plate through a screw, a plurality of dividing holes are provided on the dividing plate, and each dividing hole is evenly distributed around the axis of the joint pin, a second pin hole is provided on the base, and one end of the second dividing pin passes through the dividing hole and is inserted into the second pin hole;

[0020] The preparation method of the spherical shell piezoelectric composite material is as follows:

[0021] a. Glue the ball shell to the ball holder, and then use a cutting machine to cut the ball shell. After each cutting seam is cut, pull out the second indexing pin, rotate the indexing plate by one indexing value, insert the second indexing pin into the indexing hole corresponding to the indexing value, and then cut the ball shell again. Repeat this process until all the cutting seams are completed.

[0022] b. After cutting, fill the ball holder and the ball shell with epoxy, allowing the epoxy to enter the cutting seam;

[0023] c. After the epoxy cures, remove the spherical shell and machine the inner and outer surfaces of the spherical shell to remove excess epoxy.

[0024] d. Bond the ball shell to the ball holder again and prepare the ball shell according to steps a to c above;

[0025] e. After the spherical shell is processed, the electrode is applied to the spherical shell by magnetron sputtering, vacuum evaporation or conductive adhesive.

[0026] The invention has the following beneficial effects: high efficiency and high precision in cutting round tubes, and the ceramic phase ratio can be adjusted arbitrarily. Centripetal cutting can make the cutting direction of the ceramic ball follow the polarization direction, and the composite material has better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings:

[0028] Figure 1It is a schematic diagram of the three-dimensional structure when the piezoelectric ceramic component is a circular tube.

[0029] Figure 2 It is a schematic diagram of the top view structure when the piezoelectric ceramic component is a circular tube.

[0030] Figure 3 It is a schematic diagram of the three-dimensional structure of the branch block.

[0031] Figure 4 It is a schematic diagram of the three-dimensional structure of the finished round tube piezoelectric composite material.

[0032] Figure 5 It is a schematic diagram of the cross-sectional structure when the piezoelectric ceramic component is a spherical shell.

[0033] Figure 6 It is a schematic diagram of the three-dimensional structure when the piezoelectric ceramic component is a spherical shell.

[0034] Figure 7 Schematic diagram of the three-dimensional structure of the finished spherical shell piezoelectric composite material.

[0035] In the figure: a bracket 11, a first indexing pin 12, a core rod 13, a first plug hole 14, a round tube 15, a branching block 16, a ball shell 21, a ball head 22, a joint pin 23, a ball holder 24, a dividing plate 25, a base 26, a second indexing pin 27, and a fixing plate 28. DETAILED DESCRIPTION

[0036] Embodiment 1:

[0037] like Figures 1 to 4 As shown, when the piezoelectric ceramic to be processed is a round tube 15, the round tube 15 must be fully polarized and have piezoelectric properties. The fixture for clamping the piezoelectric ceramic round tube 15 includes a U-shaped bracket 11 and a core rod 13 assembled in the round tube 15, the core rod 13 is rotatably connected to the bracket 11 through a rotating shaft, a first pin hole is provided on the bracket 11, a first indexing pin 12 is provided in the first pin hole, and a plurality of first plug holes 14 are provided on the surface of the core rod 13, each first plug hole 14 is evenly distributed around the axis of the rotating shaft, and the first indexing pin 12 is inserted into the first plug hole 14; the preparation method of the piezoelectric composite material for the round tube 15 using the fixture is:

[0038] a. The round tube 15 is then bonded to the mandrel 13 by an adhesive, and then the round tube 15 is axially cut using a cutting machine. Each time a slit is cut on the round tube 15, the round tube 15 is rotated by an angle, and the first indexing pin 12 is inserted into the first insertion hole 14 corresponding to the angle, and then the next slit of the round tube 15 is axially cut again, and this process is repeated until the remaining slits are cut;

[0039] b. After all the slits on the round tube 15 are cut, the round tube 15 and the mandrel 13 are placed in the arc-shaped notch of the branch block 16, and the round tube 15 is cut circumferentially. After the circumferential cutting is completed, the mandrel 13 and the round tube 15 are poured with epoxy together, and the epoxy is allowed to enter the cut slits on the round tube 15;

[0040] c. After the epoxy is cured, remove the round tube 15 from the mandrel 13, and machine the outer wall of the round tube 15 to remove excess epoxy.

[0041] d. Electrodes are formed on the circular tube 15 by magnetron sputtering, vacuum evaporation or conductive adhesive.

[0042] A fixture is used to perform indexing cutting on the round tube 15 to ensure that the spacing between each gap is consistent, so that the cutting accuracy is high, the efficiency is high, and the ceramic phase ratio is adjustable.

[0043] Embodiment 2:

[0044] When the piezoelectric ceramic to be processed is a spherical shell 21, the piezoelectric ceramic spherical shell 21 is required to be fully polarized and have piezoelectric properties. The fixture for cutting piezoelectric ceramics includes a fixed plate 28, a base 26 is connected to the fixed plate 28, one end of the base 26 has a ball head 22, a slot is provided on the ball head 22, a joint pin 23 is assembled in the slot, the axis of the joint pin 23 coincides with the center of the ball head 22, a ball holder 24 sleeved on the ball head 22 is connected to the joint pin 23, one end of the ball holder 24 is connected to the indexing plate 25 by a screw, a plurality of indexing holes are provided on the indexing plate 25, and each indexing hole is evenly distributed around the axis of the joint pin 23, a second pin hole is provided on the base 26, and one end of the second indexing pin 27 passes through the indexing hole and is inserted into the second pin hole;

[0045] The method for preparing the piezoelectric composite material of the spherical shell 21 using the fixture is as follows:

[0046] a. Use adhesive to bond the ball shell 21 to the ball holder 24, and then use a cutting machine to cut the ball shell 21. After each cutting seam is cut, the second indexing pin 27 is pulled out, and after the indexing plate 25 is rotated by a division value, the second indexing pin 27 is inserted into the division hole corresponding to the division value, and then the ball shell 21 is cut again, and this process is repeated until all the cutting seams are cut;

[0047] b. After the cutting is completed, remove the screws between the ball holder 24 and the indexing plate 25, and then fill the ball holder 24 and the ball shell 21 with epoxy, allowing the epoxy to enter the cutting seam;

[0048] c. After the epoxy is cured, the spherical shell 21 is removed, and the inner and outer surfaces of the spherical shell 21 are machined to remove excess epoxy.

[0049] d. After rotating the ball shell 21 by 10 to 90 degrees, the ball shell 21 is bonded to the ball holder 24 again, and the ball shell 21 is prepared according to the above steps a to c, ensuring that the two cutting gaps are staggered;

[0050] e. After the spherical shell 21 is processed, an electrode is formed on the spherical shell 21 by magnetron sputtering, vacuum evaporation or conductive adhesive.

Claims

1. A method for preparing a special-shaped piezoelectric composite material, characterized in that: The following steps are included: a. Fix the piezoelectric ceramic piece to the fixture and cut the piezoelectric ceramic piece; b. After cutting, pour epoxy into the piezoelectric ceramic and the fixture together, and let the epoxy enter the cutting seam; c. Remove the piezoelectric ceramic from the fixture and remove excess epoxy; d. Electrodes are formed on the outer wall of the piezoelectric ceramic by magnetron sputtering, vacuum evaporation or conductive adhesive; The piezoelectric ceramic component is a round tube (15), and the fixture comprises a bracket (11) and a core rod (13) assembled in the round tube (15), the core rod (13) being rotatably connected to the bracket (11) via a rotating shaft, a first pin hole being provided on the bracket (11), a first indexing pin (12) being provided in the first pin hole, a plurality of first insertion holes (14) being provided on the surface of the core rod (13), the first insertion holes (14) being evenly distributed around the axis of the rotating shaft, and the first indexing pin (12) being inserted into the first insertion hole (14); The preparation method of the piezoelectric composite material for the circular tube (15) is as follows: a. The round tube (15) is then bonded to the mandrel (13), and then the round tube (15) is axially cut using a cutting machine. Each time a slit is cut on the round tube (15), the round tube (15) is rotated by an angle, and the first indexing pin (12) is inserted into the first insertion hole (14) corresponding to the angle, and then the round tube (15) is axially cut again, and this process is repeated until the remaining cut slits are cut.

2. The method for preparing a special-shaped piezoelectric composite material according to claim 1, characterized in that: It also includes a branch pipe block, one side of which is provided with an arc-shaped notch for accommodating a circular pipe (15); b. After the cutting seam on the circular tube (15) is cut, the circular tube (15) and the mandrel (13) are placed in the arc-shaped notch of the branch block, and the circular tube (15) is cut circumferentially. After the circumferential cutting is completed, the mandrel (13) and the circular tube (15) are poured with epoxy together, and the epoxy is allowed to enter the cutting seam on the circular tube (15); c. After the epoxy is cured, remove the round tube (15) from the mandrel (13), machine the outer wall of the round tube (15) to remove excess epoxy, d. Electrodes are formed on the circular tube (15) by magnetron sputtering, vacuum evaporation or conductive adhesive.

3. A method for preparing a special-shaped piezoelectric composite material, characterized in that: The following steps are included: a. Fix the piezoelectric ceramic piece to the fixture and cut the piezoelectric ceramic piece; b. After cutting, pour epoxy into the piezoelectric ceramic and the fixture together, and let the epoxy enter the cutting seam; c. Remove the piezoelectric ceramic from the fixture and remove excess epoxy; d. Electrodes are formed on the outer wall of the piezoelectric ceramic by magnetron sputtering, vacuum evaporation or conductive adhesive; The piezoelectric ceramic component is a spherical shell (21), and the fixture includes a fixing plate (28), the fixing plate (28) is connected to a base (26), one end of the base (26) has a ball head (22), the ball head (22) is equipped with a joint pin (23), a ball holder (24) sleeved on the ball head (22) is connected to the joint pin (23), one end of the ball holder (24) is connected to the indexing plate (25) by a screw, a plurality of indexing holes are opened on the indexing plate (25), and each indexing hole is evenly distributed around the axis of the joint pin (23), a second pin hole is opened on the base (26), and one end of the second indexing pin (27) passes through the indexing hole and is inserted into the second pin hole; The preparation method of the piezoelectric composite material of the spherical shell (21) is as follows: a. The ball shell (21) is bonded to the ball holder (24), and then the ball shell (21) is cut using a cutting machine. Each time a cutting seam is cut, the second indexing pin (27) is pulled out, and the indexing plate (25) is rotated by a division value, and then the second indexing pin (27) is inserted into the division hole corresponding to the division value, and then the ball shell (21) is cut again, and this process is repeated until all the cutting seams are cut; b. After the cutting is completed, the ball holder (24) and the ball shell (21) are filled with epoxy, and the epoxy is allowed to enter the cutting seam; c. After the epoxy is cured, the spherical shell (21) is removed, and the inner and outer surfaces of the spherical shell (21) are machined to remove excess epoxy.

4. The method for preparing a special-shaped piezoelectric composite material according to claim 3, characterized in that: Also includes d. bonding the ball shell (21) to the ball holder (24) again, and preparing the ball shell (21) according to steps a to c above; e. After the spherical shell (21) is processed, an electrode is formed on the spherical shell (21) by magnetron sputtering, vacuum evaporation or conductive adhesive.

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