Tape casting equipment and method for manufacturing piezoelectric ceramics

Abstract

This invention discloses a casting molding apparatus and a method for manufacturing piezoelectric ceramics, relating to the field of piezoelectric ceramic technology. The casting molding apparatus incorporates a second feeding hopper and a discharge pipe, enabling the production of piezoelectric ceramics with a curved interlayer extending in a wavy pattern in two directions. This wavy curved interlayer effectively absorbs external energy, improving the product's toughness and allowing for the production of novel piezoelectric ceramics with complex layer structures. The manufacturing method disclosed in this invention utilizes the aforementioned improved casting molding machine, enabling the production of piezoelectric ceramics with a curved interlayer and automating the mass production of novel piezoelectric ceramics with complex layer structures.

Description

Technical Field

[0001] The present invention relates to the technical field of piezoelectric ceramics, and more specifically to a tape casting device and a method for manufacturing piezoelectric ceramics. Background Art

[0002] Piezoelectric ceramics have been widely used since their discovery. Piezoelectric ceramics with high voltage electric strain constants have a broader application prospect due to their excellent material properties. The existing tape casting equipment has relatively simple functions and cannot produce new piezoelectric ceramics with complex layer structures. Summary of the invention

[0003] The present invention provides a tape casting device and a method for manufacturing piezoelectric ceramics, which aim to solve the above problems existing in the prior art.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A cast film forming device comprises a conveyor belt, above which a first feed hopper, a scraper and a drying furnace are arranged; it also comprises a second feed hopper arranged above the conveyor belt, the discharge port of the second feed hopper is connected to a discharge pipe with a strip-shaped discharge port opened in the conveying direction of the conveyor belt, and the discharge pipe is arranged across the width direction of the conveyor belt between the scraper and the discharge port of the first feed hopper.

[0006] Furthermore, the outer contour of the cross section of the discharge pipe is in an arch shape, and the chord of the arch is inclined toward the surface of the conveyor belt.

[0007] Furthermore, the cross-sectional profile of the strip-shaped discharge port is wavy, the discharge pipe is movably arranged on the second supply hopper up and down, and is equipped with a driving device for moving the discharge pipe up and down.

[0008] Furthermore, the driving device includes an inverted U-shaped three-way pipe, which is fixed with a lifting plate, and the second feeding hopper is fixed with a sleeve and a cylinder, the lifting plate can be inserted into the sleeve movably up and down, and the lifting plate is connected to the piston rod of the cylinder; the upper port of the inverted U-shaped three-way pipe can be movably mounted on the discharge port of the second feeding hopper up and down, and the two lower ports are connected to the discharge pipe.

[0009] A method for manufacturing piezoelectric ceramics comprises the following steps: (1) adding two different ceramic slurries into a first feed hopper and a second feed hopper of any of the above-mentioned tape casting molding equipment respectively, and moving a discharge pipe up and down to perform molding processing to obtain ceramic strips.

[0010] Furthermore, the method further comprises the following steps: (2) cutting the formed ceramic strip into ceramic blanks of a set size; (3) heating the ceramic blanks to remove organic matter to obtain green blanks; and (4) sintering the green blanks to obtain piezoelectric ceramics.

[0011] It can be seen from the above description of the present invention that, compared with the prior art, the advantages of the present invention are:

[0012] Firstly, the present invention discloses a tape casting machine, which adds a second feed hopper and a discharge pipe, and can produce piezoelectric ceramics with a curved interlayer extending in a wavy shape in two directions in the middle. The curved interlayer with a wavy structure can absorb external energy well, improve the toughness of the product, and can be used to produce new piezoelectric ceramics with complex layer structures.

[0013] Secondly, the present invention discloses a method for manufacturing piezoelectric ceramics. The piezoelectric ceramics with intermediate curved surface sandwich layers are manufactured by the improved tape-casting machine, and new piezoelectric ceramics with complex layer structures can be automatically mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of the tape casting machine in the present invention.

[0015] Figure 2 for Figure 1 , an enlarged schematic diagram of part A. Among them, the first feeding hopper, the inverted U-shaped three-way pipe and the discharge pipe are cross-sectional views.

[0016] Figure 3 The first feeding hopper, the second feeding hopper, the discharge pipe and the driving device are provided along the Figure 1 Schematic diagram of the BB direction.

[0017] Figure 4 Schematic diagram of the cross-sectional profile of the strip discharge port.

[0018] Figure 5 A cross-sectional view of a piezoelectric ceramic. DETAILED DESCRIPTION

[0019] The specific implementation of the present invention is described below with reference to the accompanying drawings. In order to fully understand the present invention, many details are described below, but for those skilled in the art, the present invention can be implemented without these details.

[0020] like Figures 1 to 4 As shown, a tape casting device and a method for manufacturing piezoelectric ceramics mainly include a conveyor belt 1, a first feed hopper 2, a second feed hopper 3, a driving device 4, a discharge pipe 5, a scraper 6 and a drying furnace 7. Among them, the first feed hopper 2, the second feed hopper 3, the scraper 6 and the drying furnace 7 are arranged above the conveyor belt 1 along the conveying direction of the conveyor belt 1. The conveyor belt 1, the first feed hopper 2, the scraper 6 and the drying furnace 7 are all common mechanical structures of existing tape casting machines. Those skilled in the art can implement them according to the specification in accordance with the existing technology, and will not be repeated here.

[0021] like Figures 1 to 4 As shown, the discharge port 31 of the second feed hopper 3 is connected to a discharge pipe 5 with a strip discharge port 51 in the conveying direction of the conveyor belt 1, and the discharge pipe 5 is arranged across the width direction of the conveyor belt between the scraper 6 and the discharge port 21 of the first feed hopper 2. Preferably, the strip discharge port 51 is located below the scraper 6.

[0022] like Figures 1 to 4 As shown, specifically, the discharge pipe 5 can be movably arranged on the second feeding hopper 3, and is equipped with a driving device 4 that moves the discharge pipe 5 up and down. Preferably, it also includes an inverted U-shaped three-way pipe 40, the outer wall of the inverted U-shaped three-way pipe 40 is fixed with a lifting plate 41, the outer wall of the second feeding hopper 3 is fixed with a sleeve 42 and a cylinder 43, the lifting plate 41 can be inserted into the sleeve 42 movably up and down, and the upper end of the lifting plate 41 is connected to the piston rod of the cylinder 43. At the same time, the upper end of the inverted U-shaped three-way pipe 40 can be movably sleeved on the discharge port 31 of the second feeding hopper 3, and the two lower ends of the inverted U-shaped three-way pipe 40 are fixedly connected and connected to the discharge pipe 5. Among them, the inverted U-shaped three-way pipe 40, the lifting plate 41, the sleeve 42 and the cylinder 43 constitute the driving device 4, of course, the specific structure of the driving device 4 does not belong to this.

[0023] like Figures 1 to 4 As shown, as a preferred embodiment, the cross-sectional outer contour of the discharge pipe 5 is in an arch shape, and the chord of the arch is inclined toward the surface of the conveyor belt 1. The inclined setting can reduce the resistance of the discharge pipe 5 when it moves up and down, and the setting mode of the arched surface facing up and the chord facing down can make the upper layer of porcelain slurry flowing out of the hopper port 21 generate a strong downward pressure flow after passing over the arc surface, which can produce a certain compaction effect.

[0024] like Figures 1 to 4 As shown, as a preferred embodiment, the cross-sectional profile of the strip-shaped discharge port 51 is wavy. When the first feeding hopper 2 and the second feeding hopper 3 feed simultaneously and flow forward with the conveyor belt 1, due to the wavy shape of the strip-shaped discharge port 51 and its up and down movement, the porcelain slurry flowing out of the strip-shaped discharge port 51 is in the middle of another porcelain slurry flowing out of the discharge port 21, and a piezoelectric ceramic having a curved interlayer extending in a wavy shape in two directions can be obtained in the middle. The curved interlayer with a wavy structure can absorb external energy well and improve the toughness of the product.

[0025] A method for manufacturing a piezoelectric ceramic comprises the following steps:

[0026] (1) Two different porcelain slurries are added to the first feeding hopper 2 and the second feeding hopper 3 of the tape casting equipment, respectively, and the conveyor belt 1, the driving device 4 and the drying furnace 7 are started to perform the molding process to obtain porcelain strips. The discharge pipe 5 moves up and down under the action of the driving device 4.

[0027] Preferably, dry grinding is used to obtain various raw material powders satisfying D50≤1.0μm, Dmax≤6.0μm, and then the raw material powders are mixed according to the chemical composition of Pb(Zr 0.52 Ti 0.48 )O3 is used to configure the powders of various raw materials to obtain a mixture; the mixture and zirconium balls are added into a vibration mill at a mass ratio of 1:3 to mix; then the uniformly mixed mixture is taken out, put into an alumina crucible, and calcined in a box furnace to synthesize a piezoelectric ceramic frit; after the piezoelectric ceramic frit is cooled, it is taken out, coarsely crushed, and vibration-milled into the PZT series piezoelectric ceramic powder with D50≤1.0μm and Dmax≤6.0μm; glue, defoaming agent and water are added to the PZT series piezoelectric ceramic powder, and stirred to form a ceramic slurry A.

[0028] According to the chemical composition (Pb 0.95 Sr 0.05 )(Zr 0.52 Ti 0.48 )O3 configures the raw material powders and mixes them evenly to obtain a mixture; then the mixture is calcined to synthesize a frit; then the frit is vibrated to form a PZT-based piezoelectric ceramic powder with D50≤1.0μm and Dmax≤6.0μm; glue, defoamer and water are added to the PZT-based piezoelectric ceramic powder and stirred to form a porcelain slurry; then based on the weight of the PZT-based piezoelectric ceramic powder, 0.6wt% of the mullite fiber with a fiber diameter of 2-7μm and a fiber length of 5-50μm is weighed and added to the slurry and stirred evenly to obtain the porcelain slurry B. Porcelain slurry B improves piezoelectric ceramics by adding a second phase of special mullite fiber, which can achieve the purpose of toughening and maintaining piezoelectric properties.

[0029] When in use, the above-mentioned porcelain slurry A is added into the first supply hopper 2, and the above-mentioned porcelain slurry B is added into the second supply hopper 3.

[0030] (2) Cut the formed porcelain strips into porcelain blanks of set sizes.

[0031] (3) The temperature of the porcelain body is raised to 700°C to 850°C to remove organic matter and obtain a green body.

[0032] (4) The green blank is sintered at 1100-1300°C to obtain piezoelectric ceramics.

[0033] like Figure 5 As shown, the piezoelectric ceramic manufactured by the above manufacturing method includes an upper layer 101, a middle layer 102 and a lower layer 103 stacked in sequence from top to bottom.

[0034] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A tape casting device, comprising a conveyor belt, above which a first feed hopper, a scraper and a drying furnace are arranged, characterized in that: It also includes a second feeding hopper arranged above the conveyor belt, the discharge port of the second feeding hopper is connected to a discharge pipe with a strip-shaped discharge port opened in the conveying direction of the conveyor belt, and the discharge pipe is arranged across the width direction of the conveyor belt between the scraper and the discharge port of the first feeding hopper; the cross-sectional outer contour of the discharge pipe is arch-shaped, and the chord of the arch is inclined toward the surface of the conveyor belt; the cross-sectional contour of the strip-shaped discharge port is wavy, and the discharge pipe can be movably arranged on the second feeding hopper up and down, and is equipped with a driving device that moves the discharge pipe back and forth up and down; the driving device includes an inverted U-shaped three-way pipe, the inverted U-shaped three-way pipe is fixedly provided with a lifting plate, the second feeding hopper is fixedly provided with a sleeve and a cylinder, the lifting plate can be inserted into the sleeve movably up and down, and the lifting plate is connected to the piston rod of the cylinder; the upper port of the inverted U-shaped three-way pipe can be movably sleeved on the discharge port of the second feeding hopper up and down, and the two lower ports are connected to the discharge pipe, and the strip-shaped discharge port is located below the scraper.

2. A method for manufacturing a piezoelectric ceramic, characterized in that: The method comprises the following steps: (1) adding two different ceramic slurries into the first feeding hopper and the second feeding hopper of the tape casting molding device as claimed in claim 1 respectively, and moving the discharge pipe up and down to perform molding processing to obtain ceramic strips.

3. The method for manufacturing a piezoelectric ceramic according to claim 2, characterized in that: The following steps are also included: (2) Cutting the formed ceramic strip into ceramic blanks of set size; (3) Heating the ceramic blanks to remove organic matter to obtain green blanks; (4) Sintering the green blanks to obtain piezoelectric ceramics.

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