Ultrasonic dental cleaning vibration system and method of manufacturing the same

Abstract

The application discloses an ultrasonic dental cleaning vibration system and a preparation method thereof. The system is prepared by introducing high Curie temperature ceramic materials, a conical compound amplitude transformer and a high-heat-conductivity anti-adhesion structure, and by combining powder injection molding technology, plastic deformation technology and ion sputtering technology, so that the preparation technology of the ultrasonic dental cleaning vibration system is broken through. The system has the characteristics of high output power, good stability and simple structure design, and can well meet the demand of ultrasonic dental cleaning equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of dental cleaning system and its preparation method, more particularly to a kind of ultrasonic dental cleaning vibration system and its preparation method, belong to ultrasonic surgical instrument processing technical field. BACKGROUND

[0002] Ultrasonic wave refers to the sound wave above 20KHz, because of its directivity, penetration, has been widely used in ultrasonic dental cleaning, ultrasonic ablation, ultrasonic atomization, B ultrasonic examination and many other medical fields.Compared with traditional surgery, ultrasonic dental cleaning surgery has the advantages of high efficiency, fast speed, light trauma, less bleeding, etc., which brings great benefits to doctors and patients.

[0003] Ultrasonic dental cleaning system is mainly composed of high-frequency power source (generator) and ultrasonic vibration system.The ultrasonic vibration system includes three parts: piezoelectric transducer, amplitude transformer and working tip.Among them, piezoelectric transducer is a device for energy conversion, which converts the electrical energy generated by ultrasonic generator into mechanical energy through the piezoelectric effect of piezoelectric ceramic, and radiates through the amplitude transformer to make the working tip form reciprocating vibration.The working tip contacts the tooth, and uses mechanical vibration to remove calculus, pigment and smoke spots on the tooth, etc., to achieve the effect of cleaning and protecting the tooth.

[0004] In ultrasonic dental cleaning system, ultrasonic vibration system is the key component, and its characteristics directly affect the performance of the whole system.A perfect ultrasonic dental cleaning vibration system should have the performance characteristics of high power and high stability.In power ultrasound, the energy of mechanical wave is proportional to the square of its amplitude, and power is the energy per unit time.That is, the larger the amplitude of ultrasonic vibration system, the greater the output power per unit time, which is more conducive to processing.Currently, the common methods to increase the output amplitude include increasing the excitation voltage and using stepped amplitude transformer.However, the increase of voltage may damage the equipment and cause radiation and interference to the surrounding environment;Although the stepped amplitude transformer has a large amplification factor, its cross-section changes in a jump, and the shape factor is less than 1, and the stress often exceeds the allowable stress of the material.Even if a high-power ultrasonic vibration system is finally obtained, its stability is not good, and it cannot guarantee high-power output during the whole dental cleaning process, which affects the dental cleaning effect.This is because, first, the temperature of piezoelectric ceramic rises, and the electromechanical conversion efficiency decreases, and when the temperature exceeds the Curie temperature, the piezoelectric effect will disappear;Second, the temperature of the working tip rises sharply, which may cause the phenomenon of tissue adhesion, although waterway structure can be added between the transducer and the amplitude transformer, but the processing cost is also increased.Therefore, how to obtain an ultrasonic dental cleaning vibration system with high power and high stability is a problem to be solved at present. SUMMARY

[0005] The present application provides an ultrasonic dental cleaning vibration system and a preparation method thereof to overcome the shortcomings of the prior art.

[0006] To achieve the above object, the present application adopts the following technical scheme:

[0007] The present application provides an ultrasonic dental cleaning vibration system, characterized in that it comprises a piezoelectric transducer, a composite amplitude transformer and a working tip.

[0008] The piezoelectric transducer comprises a back cover plate, a conductive sheet, piezoelectric ceramic sheets and a front cover plate.

[0009] The composite amplitude transformer comprises a large-end cylindrical segment, a transition segment and a small-end cylindrical segment. In the formula, k is the wave number, and A is a coefficient, A = 0.005-0.01.

[0010] The material of the composite amplitude transformer is one of TC4 and TC11.

[0011] The working tip comprises a base material and a coating layer.

[0012] The base material of the working tip is one of 2Cr13, 3Cr13 and 4Cr13. The coating layer of the working tip is one of diamond and silver.

[0013] As a preferred solution, the ultrasonic dental vibration system is characterized in that the rear cover plate is arranged at the rear end of the piezoelectric transducer, the rear cover plate is provided with a screw structure, the front cover plate is arranged at the front end of the piezoelectric transducer, the conductive sheet and the piezoelectric ceramic sheet are arranged between the rear cover plate and the front cover plate, the front cover plate of the piezoelectric transducer and the composite amplitude transformer adopt an integrated structure, the material of the rear cover plate is one of copper, 304L and 316L stainless steel, the material of the conductive sheet is one of pure copper and zinc white copper, and the material of the front cover plate is one of TC4 and TC11.

[0014] As a preferred solution, the ultrasonic dental vibration system is characterized in that the working frequency of the ultrasonic dental vibration system is 25-45 kHz.

[0015] The preparation method of the ultrasonic dental vibration system is characterized in that the following steps are included:

[0016] S1: piezoelectric ceramic preparation, PZT and LaBi2FeWO9 ceramic powder are sequentially subjected to mixing, injection molding, debinding and sintering to obtain a piezoelectric ceramic product, and the sintering process is as follows: under a vacuum degree of ≤5*10 -3 Pa, the temperature is raised to 1250-1350℃ at a temperature raising rate of 5-10℃ / min, the temperature is kept for 1-4h, and then the furnace is discharged by rapidly reducing the temperature to 100℃ at a rate of 30-60℃ / min;

[0017] S2: rear cover plate and conductive sheet preparation, the above parts are obtained by finish machining;

[0018] S3: front cover plate and composite amplitude transformer preparation, the above parts are sequentially subjected to batching, smelting and casting, blooming and forging, drawing and cryogenic treatment to obtain a rod, and finally finish machining is performed, and the cryogenic treatment process is as follows: keeping the temperature at -60 to -100℃ for 2-6h and air cooling;

[0019] S4: working tip preparation, the base material part is sequentially subjected to batching, smelting and casting, forging, heat treatment and finish machining, the cylindrical array structure is formed by micro-EDM, and a coating is deposited on the surface of the base material by ion sputtering using one of graphite and silver targets to obtain a working tip product, the sputtering power used is 200-400w, the negative bias voltage is -150 to -30V, and the sputtering time is 0.5-1h;

[0020] S5: ultrasonic vibration system assembly, first, the conductive sheet, the piezoelectric ceramic sheet, the front cover plate and the composite amplitude transformer are connected and fixed together through the screws on the rear cover plate, and the coaxiality is within 0.02mm, then the composite amplitude transformer and the working tip are connected through threads, and finally aging treatment is performed to obtain the ultrasonic dental vibration system.

[0021] As a preferred solution, the preparation method of the ultrasonic dental cleaning vibration system is characterized in that the average particle size of the PZT and LaBi2FeWO9 powder is 200-400 nm.

[0022] As a preferred solution, the preparation method of the ultrasonic dental cleaning vibration system is characterized in that the injection temperature of the injection molding is 120-180℃, and the injection pressure is 70-140 MPa.

[0023] As a preferred solution, the preparation method of the ultrasonic dental cleaning vibration system is characterized in that the smelting and casting is a vacuum consumable arc furnace smelting method.

[0024] As a preferred solution, the preparation method of the ultrasonic dental cleaning vibration system is characterized in that the blooming forging temperature is 950-1100℃, the drawing temperature is 700-850℃, and the drawing rate is 5-10 mm / s.

[0025] As a preferred solution, the preparation method of the ultrasonic dental cleaning vibration system is characterized in that the aging process is: 90-120℃ for 1-4 h, and furnace cooling.

[0026] Principle and advantage

[0027] The piezoelectric transducer is a device for energy conversion, which uses piezoelectric ceramic to convert the oscillation electric signal generated by the ultrasonic generator into mechanical vibration signal, i.e. to convert electric energy into mechanical energy. Therefore, piezoelectric ceramic material directly affects the performance of the piezoelectric transducer.

[0028] It is found that the ferroelectric lead titanate (PbTiO3) and the antiferroelectric lead zirconate (PbZrO3) can form a continuous solid solution lead zirconate titanate piezoelectric ceramic (PZT), which has excellent piezoelectric properties near the morphotropic phase boundary (MPB) composition. It soon replaced BaTiO3 piezoelectric ceramic and became the most widely used piezoelectric material. In recent years, with the further expansion of the application range of piezoelectric materials, new challenges have been put forward for the service performance of piezoelectric ceramics in some extreme environments. For example, high-power piezoelectric transducers for ultrasonic dental cleaning must select piezoelectric materials with high Curie point, so that the piezoelectric device can work normally in a wider temperature range.

[0029] The ultrasonic dental piezoelectric transducer on the market mostly uses traditional PZT piezoelectric ceramic. Although the PZT piezoelectric ceramic has the advantages of high piezoelectric coefficient, stable performance and high mechanical strength, its Curie temperature Tc is about 360℃, so the safe use temperature is only below 180℃. If the service temperature of the piezoelectric ceramic exceeds 1 / 2Tc, serious depolarization of the piezoelectric ceramic will be caused, resulting in degradation or even loss of piezoelectric performance. According to the structural characteristics of bismuth layer-structured oxide, it is formed by regularly alternating arrangement of perovskite layers with ABO3 structure and bismuth-containing (Bi2O2) layers along the c-axis direction of the bismuth layer-structured oxide. 2+ In the process of technical development, the inventors found that when La 3+ coordination ions are used at the A site and Fe 3+ , W 6+ coordination ions are used at the B site, the chemical general formula of the composition is LaBi2FeWO9, at this time, the tolerance factor t has a smaller value, and the tolerance factor t is calculated by the following formula:

[0030]

[0031] In the formula, rA, rB and rO are the radii of A site, B site and O ions respectively, the smaller the tolerance factor t is, the higher the Curie temperature of the bismuth layer-structured oxide is. Meanwhile, it also has the following main characteristics: strong spontaneous polarization, low dielectric constant, low aging rate, good time and temperature stability of resonant frequency, high mechanical quality factor and easy sintering. However, due to the high coercive field of the bismuth layer-structured oxide, it is not conducive to polarization, so it is usually necessary to control the thickness of the bismuth layer-structured oxide to be in millimeter or even micrometer level. Therefore, the new type of the present application is prepared by powder injection molding technology. Powder injection molding is a near-net-shaping method, especially in the preparation of thin-walled and complex structural parts, it has incomparable advantages over traditional processes. It mixes the high molecular binder with PZT and LaBi2FeWO9 ceramic powder respectively to obtain the feedstock, then alternately injects the two kinds of feedstock into the mold to obtain a specific shape of the blank, and finally carries out debinding and sintering, so as to prepare a composite piezoelectric ceramic part with high Curie temperature and high piezoelectric coefficient. It has the characteristics of simple process, high production efficiency, low cost and easy batch production.

[0032] The vibration amplitude of the piezoelectric transducer is usually only a few microns, which cannot meet the needs of ultrasonic dental surgery. Therefore, a horn needs to be installed in front of the transducer, and mechanical energy is transmitted to the horn through the front cover plate, and then the interface changes to make the ultrasonic energy gather, so as to amplify the amplitude of the output end. During dental treatment, if the horn has a larger output amplitude, the output amplitude of the working tip is also larger under the same conditions, which is convenient for better cleaning of dental calculus and obtaining better clinical effect. Therefore, higher output amplitude is considered as a key performance indicator of the horn.

[0033] To improve the output amplitude of the amplitude transformer, this invention addresses both material preparation and structural design. Regarding material preparation, firstly, ingots are obtained using a vacuum arc furnace melting method according to the composition requirements of TC4 or TC11, ensuring uniform distribution of alloying elements within the electrodes while avoiding the introduction of high-density and low-density inclusions during melting. Then, the microstructure is refined through forging and drawing processes. Through extensive experimentation, the plastic deformation process parameters for forging and drawing have been determined. Under these parameters, a fine and uniform titanium alloy microstructure (3–6 μm in size) can be obtained, while controlling the volume fraction of the β phase at 20%–30%, effectively reducing the elastic modulus and contributing to increased amplitude. After plastic deformation, the titanium alloy retains internal stresses that are in self-equilibrium, also known as residual stresses, after the removal of external forces or uneven temperature fields. These residual stresses increase the acoustic impedance of the titanium alloy, which is detrimental to improving the amplitude of the amplitude transformer. Therefore, this invention utilizes cryogenic processing to generate thermal stress opposite to the residual stress through rapid cooling, thereby offsetting the original stress field and significantly reducing residual stress to lower the material's acoustic impedance. In terms of structural design, a single-shaped stepped amplitude transformer typically fails to meet the requirements of high amplitude and low stress. Therefore, this invention employs a composite amplitude transformer composed of combinations of single shapes to improve output performance. Assuming the amplitude transformer material is homogeneous and isotropic, and neglecting mechanical losses and damped vibrations, the plane longitudinal wave propagates along the axis of the transformer. The vibration equation of the amplitude transformer in one dimension is:

[0034]

[0035] In the formula: ξ=ξ(x) is the particle displacement function; k=ω / c, k is the wave number. Let ω be the propagation velocity of the longitudinal wave in the material, E be the elastic modulus of the material, and ρ be the density of the material; S = S(x) is the cross-sectional area at any position x on the axis.

[0036] for Figure 1 The conical composite amplitude transformer shown is given with l1 = l3. According to formula (1), the displacement distribution function of each segment of the transformer can be obtained:

[0037] ξ Ι =ξ1cos(kx+kl1)

[0038]

[0039] ξ Ⅲ =α3ξ1cos[kx-(kl2+kl3)]

[0040] In the formula: xi, xi, xi are the displacement distribution functions of the particles of each section of the rod; xi, xi are the displacements of the large and small end faces of the amplitude-varying rod; l1, l2, l3 are the lengths of each section of the amplitude-varying rod; alpha=(N-1) / Nl2 is the taper coefficient; N=S1 / S2 is the area ratio; S1, S2 are the areas of the large and small end faces of the conical rod.

[0041] The displacement node is calculated as:

[0042] The magnification is: M=|N[cos(kl2)-tanAsin(kl2)]|

[0043] The inventor finds that when A is 0.005-0.01, M has a larger value.

[0044] In the dental cleaning operation, the working tip is easy to paste substances including coagulant, protein, blood, tissue particles and other component fluids, and the accumulation of these substances increases the impedance of the working tip and reduces the cutting performance. In order to improve the thermal conductivity and hydrophobicity of the working tip to achieve the purpose of anti-adhesion, the working tip is introduced into the high-thermal-conductivity anti-adhesion structure. Firstly, a micron-level cylindrical array structure is machined by micro electrical discharge, and the micron-level hierarchical microstructure can stably adsorb an air film, effectively hinders the infiltration of substances on the surface, so that the surface has super-hydrophobic performance. Then, a layer of diamond and silver with high thermal conductivity value is deposited on the surface of the substrate, which is beneficial to improve the thermal conductivity of the coating. The deposition is realized by ion sputtering technology. Under the action of the magnetic field, the electrons change the Ar atoms into Ar ions. The Ar ions bombard the target under the action of the electric field, and the sputtered atoms form a film on the surface of the substrate, improving the heat dissipation performance of the working tip and effectively reducing the adhesion of high temperature to the tissue.

[0045] Compared with the prior art, the advantages of the present application are as follows:

[0046] 1) High output power. The use of PZT piezoelectric ceramic with high piezoelectric constant and high amplitude titanium alloy amplitude-varying rod material and structure size ensures that the ultrasonic vibration system has high output power;

[0047] 2) High stability. The use of LaBi2FeWO9 with high Curie temperature and high-thermal-conductivity anti-adhesion structure greatly improves the service temperature of the ceramic, effectively reduces the adhesion to the tissue, and improves the stability of the ultrasonic vibration system;

[0048] 3) Simple structure design. The piezoelectric transducer and the amplitude-varying rod are mainly in cylindrical structure without special shape structure.

[0049] In summary, this invention, by introducing high Curie temperature ceramic materials, a conical composite amplitude transformer, and a high thermal conductivity anti-adhesion structure, and by combining powder injection molding technology, plastic deformation technology, and ion sputtering technology, has broken through the manufacturing technology of ultrasonic scaling vibration systems. It features high output power, good stability, and simple structural design, and can well meet the needs of ultrasonic scaling equipment. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of a conical composite amplitude transformer.

[0051] Figure 2 This is a schematic diagram of an ultrasonic dental cleaning vibration system, in which 1-working tip, 2-composite amplitude transformer, 3-front cover plate, 4-piezoelectric ceramic, 5-conductive sheet, and 6-rear cover plate.

[0052] Figure 3 This is a schematic diagram of the thickness direction of the piezoelectric ceramic, where 1 is the PZT layer and 2 is the high Curie temperature layer.

[0053] Figure 4 It is the microstructure of the composite amplitude transformer, in which the black phase is the α phase and the white phase is the β phase.

[0054] Figure 5 This is a schematic diagram of the working tip cross-section, where 1-coating and 2-substrate. Detailed Implementation

[0055] The method of the present invention will be further illustrated below with two examples.

[0056] Example 1:

[0057] An ultrasonic dental cleaning vibration system and its preparation method are described below:

[0058] S1: Piezoelectric ceramic preparation. PZT and LaBi2FeWO9 ceramic powders with an average particle size of 200nm were selected. The mixture underwent sequential mixing, alternating injection molding, debinding, and sintering to obtain the piezoelectric ceramic product. The thickness of the piezoelectric ceramic sheet was 2mm, the thickness of each PZT layer was 80µm, and the thickness of each high Curie temperature layer was 50µm. The injection temperature was 150℃, and the injection pressure was 90MPa. The sintering process was carried out under a vacuum degree ≤5×10⁻⁶. -3 Under a vacuum of Pa, the temperature was increased to 1250°C at a heating rate of 5°C / min, held for 3 hours, and then rapidly cooled to 100°C at a rate of 40°C / min before being removed from the furnace.

[0059] S2: Preparation of the back cover plate and conductive sheet, which are made of 316L and pure copper, respectively, and are obtained through precision machining;

[0060] S3: front cover plate and composite amplitude changer, both of which are TC4, are sequentially subjected to batching, vacuum self-consumption arc furnace smelting, cogging forging, drawing, cryogenic treatment to obtain a rod, and finally finish machining to obtain a finished product, the cogging forging temperature is 1000℃, the drawing temperature is 750℃, the drawing rate is 6mm / s, the cryogenic process is: -80℃ for 4h, air cooling, the average grain size of the α phase in the microstructure of the composite amplitude changer is 4um, the volume fraction of the β phase is 25%, the lengths of the large and small end cylindrical segments and the transition segment of the composite amplitude changer are 20, 20 and 14mm respectively, the diameters of the large and small end cylindrical segments are 10 and 5mm respectively, and the displacement node is 0.006;

[0061] S4: working tip preparation, the base material 2Cr13 is sequentially subjected to batching, smelting casting, forging, heat treatment, and finish machining to obtain, the cylindrical array structure is formed by micro-EDM, the cylindrical diameter is 15um, the cylindrical height is 20um, the spacing between two adjacent cylinders is 30um, a 2um thick diamond coating is deposited on the surface of the base material by ion sputtering to obtain the working tip finished product, the sputtering power used is 250w, the negative bias voltage is -100V, and the sputtering time is 0.5h;

[0062] S5: ultrasonic vibration system assembly, first, the conductive sheet, the four piezoelectric ceramic sheets, the front cover plate and the composite amplitude changer are connected and fixed together through the screws on the rear cover plate, and the coaxiality is within 0.02mm, then the composite amplitude changer and the working tip are connected through threads, and finally aging treatment is performed to obtain the ultrasonic dental cleaning vibration system, the aging process is: 90℃ for 4h, cooling in the furnace.

[0063] Example 2:

[0064] An ultrasonic dental cleaning vibration system and a preparation method thereof, the process is as follows:

[0065] S1: piezoelectric ceramic preparation, PZT and LaBi2FeWO9 ceramic powders with an average particle size of 200nm are selected, and piezoelectric ceramic products are obtained by sequentially mixing, alternating injection, debinding and sintering, the thickness of the piezoelectric ceramic sheet is 2.5mm, the thickness of each PZT layer is 90um, the thickness of each high Curie temperature layer is 60um, the injection temperature used is 150℃, the injection pressure is 90MPa, and the sintering process is: under a vacuum degree ≤5×10 -3 Pa vacuum environment, heating at a rate of 5℃ / min to 1280℃, holding for 3h, and then rapidly cooling at a rate of 40℃ / min to 100℃ to discharge the furnace;

[0066] S2: rear cover plate and conductive sheet preparation, their materials are 304L and pure copper respectively, and both are obtained by finish machining;

[0067] S3: front cover plate and composite amplitude rod, both of which are TC11, are sequentially subjected to batching, vacuum consumable arc furnace smelting, blooming forging, drawing, cryogenic treatment to obtain a rod, and finally finish machining to obtain a finished product, the blooming forging temperature is 1050℃, the drawing temperature is 780℃, the drawing rate is 6mm / s, the cryogenic process is: -80℃ for 4h, air cooling, the average grain size of the α phase in the microstructure of the composite amplitude rod is 3um, the volume fraction of the β phase is 28%, the lengths of the large and small end cylindrical segments and the transition segment of the composite amplitude rod are 20.5, 20.5 and 12.4mm respectively, the diameters of the large and small end cylindrical segments are 12 and 6mm respectively, and the displacement node is 0.0055;

[0068] S4: working tip preparation, the base material 3Cr13 is sequentially subjected to batching, smelting casting, forging, heat treatment, and finish machining to obtain, the cylindrical array structure is formed by micro-EDM, the cylindrical diameter is 18um, the cylindrical height is 30um, the spacing between two adjacent cylinders is 30um, a 2um thick silver coating is deposited on the surface of the base material by ion sputtering to obtain the working tip finished product, the sputtering power used is 260w, the negative bias voltage is -120V, and the sputtering time is 0.5h;

[0069] S5: ultrasonic vibration system assembly, first, the conductive sheet, the four piezoelectric ceramic sheets, the front cover plate, and the composite amplitude rod are connected and fixed together through the screws on the rear cover plate, and the coaxiality is within 0.02mm, then the composite amplitude rod and the working tip are connected through threads, and finally aging treatment is performed to obtain the ultrasonic dental cleaning vibration system, the aging process is: 100℃ for 3h, and cooling in the furnace.

[0070] Example 3:

[0071] An ultrasonic dental cleaning vibration system and a preparation method thereof, the process is as follows:

[0072] S1: piezoelectric ceramic preparation, PZT and LaBi2FeWO9 ceramic powders with an average particle size of 250nm are selected, and a piezoelectric ceramic product is obtained by sequentially mixing, alternating injection, debinding, and sintering, the thickness of the piezoelectric ceramic sheet is 3mm, the thickness of each PZT layer is 100um, the thickness of each high Curie temperature layer is 60um, the injection temperature used is 150℃, the injection pressure is 90MPa, and the sintering process is: under a vacuum degree ≤5×10 -3 Pa vacuum environment, heating to 1300℃ at a rate of 5℃ / min, holding for 2h, and then rapidly cooling to 100℃ at a rate of 40℃ / min to discharge the furnace;

[0073] S2: rear cover plate and conductive sheet preparation, their materials are 316L and zinc white copper respectively, and both are obtained by finish machining;

[0074] S3: the front cover plate and the composite amplitude transformer, both of which are made of TC4, are sequentially subjected to batching, vacuum self-consumption arc furnace smelting, cogging forging, drawing, cryogenic treatment to obtain a rod, and finally finish machining to obtain a finished product, the cogging forging temperature is 1050℃, the drawing temperature is 800℃, the drawing rate is 8mm / s, the cryogenic process is: -100℃ for 4h, air cooling, the average grain size of the α phase in the microstructure of the composite amplitude transformer is 5um, the volume fraction of the β phase is 25%, the lengths of the large and small end cylindrical segments and the transition segment of the composite amplitude transformer are 20, 20 and 14mm respectively, the diameters of the large and small end cylindrical segments are 10 and 5mm respectively, and the displacement node is 0.006;

[0075] S4: the working tip preparation, the base material 4Cr13 is sequentially subjected to batching, smelting casting, forging, heat treatment, finish machining to obtain, the cylindrical array structure is formed by micro-EDM, the cylindrical diameter is 20um, the cylindrical height is 30um, the distance between two adjacent cylinders is 35um, a diamond coating with a thickness of 2.5um is deposited on the surface of the base material by ion sputtering to obtain the working tip finished product, the sputtering power used is 320w, the negative bias voltage is -100V, and the sputtering time is 1h;

[0076] S5: ultrasonic vibration system assembly, first, the conductive sheet, the four piezoelectric ceramic sheets, the front cover plate and the composite amplitude transformer are connected and fixed together through the screws on the back cover plate, and the coaxiality is within 0.02mm, then the composite amplitude transformer and the working tip are connected through threads, and finally the aging treatment is performed to obtain the ultrasonic dental cleaning vibration system, the aging process is: 120℃ for 2h, and cooling in the furnace.

[0077] The above-described examples are only the preferred implementation methods of the present application, and therefore cannot limit the implementation scope of the present application, and other equivalent changes, modifications, substitutions and combinations made according to the principles and contents of the present application still belong to the protection scope of the present application.

Claims

1. An ultrasonic dental cleaning vibration system, comprising: The piezoelectric transducer comprises a back cover plate, a conductive sheet, piezoelectric ceramic sheets and a front cover plate; the piezoelectric ceramic sheets comprise lead zirconate titanate (PZT) layers and high Curie temperature layers, the PZT layers and the high Curie temperature layers are arranged alternately along the thickness direction, the number of the piezoelectric ceramic sheets is 2-8, the thickness of each piezoelectric ceramic sheet is 2-3 mm, the thickness of each PZT layer is 50-100 um, the thickness of each high Curie temperature layer is 30-80 um, and the material of the high Curie temperature layer is LaBi2FeWO9; The material of the composite amplitude transformer is one of TC4 and TC11, and the microstructure of the composite amplitude transformer comprises an alpha phase and a beta phase, the average grain size of the alpha phase is 3-6 um, and the volume fraction of the beta phase is 20%-30%; The composite amplitude transformer comprises a large-end cylindrical section, a transition section and a small-end cylindrical section, the generatrix shape of the transition section is conical; the length l2 of the transition section is (0.5-0.8)*l1, and l1=l3, wherein l1 and l3 are the lengths of the large-end and small-end cylindrical sections respectively; the diameter ratio N of the large-end and small-end cylinders is D1 / D3=2-3, wherein D1 and D3 are the diameters of the large-end and small-end cylindrical sections respectively; the displacement node of the composite amplitude transformer is wherein k is the wave number, and A is a coefficient, A=0.005-0.

01. The working tip comprises a base material and a coating layer, the surface of the base material is uniformly provided with a cylindrical array structure, and the surface of the base material is provided with a coating layer; in the cylindrical array, the diameter of the cylinder is 15-25 um, the height of the cylinder is 20-40 um, and the distance between two adjacent cylinders is 30-50 um; The material of the base material of the working tip is one of 2Cr13, 3Cr13 and 4Cr13, the material of the coating layer of the working tip is one of diamond and silver, and the thickness of the coating layer is 1-3 um. The back cover plate is arranged at the rear end of the piezoelectric transducer, the back cover plate is provided with a screw structure, the front cover plate is arranged at the front end of the piezoelectric transducer, the conductive sheet and the piezoelectric ceramic sheets are arranged between the back cover plate and the front cover plate, the front cover plate of the piezoelectric transducer and the composite amplitude transformer adopt an integrated structure, the material of the back cover plate is one of copper, 304L and 316L stainless steel, the material of the conductive sheet is one of pure copper and zinc white copper, and the material of the front cover plate is one of TC4 and TC11.

2. An ultrasonic dental cleaning vibration system according to claim 1, wherein The working frequency of the ultrasonic dental cleaning vibration system is 25-45 kHz.

3. An ultrasonic dental cleaning vibration system according to claim 1, wherein The method comprises the following steps:

4. A method of manufacturing an ultrasonic dental cleaning vibration system according to claim 1 or 2 or 3, characterized in that, S2: back cover plate and conductive sheet preparation, the parts are obtained by finish machining; S1: piezoelectric ceramic preparation, PZT and LaBi2FeWO9 ceramic powder are sequentially subjected to mixing, injection molding, debinding and sintering to obtain piezoelectric ceramic products, and the sintering process is as follows: under the vacuum degree ≤5×10 -3 A vacuum environment of 5-10℃ / min, the temperature is raised to 1250-1350℃, and the temperature is kept for 1-4h, and then the temperature is rapidly lowered to 100℃ at the rate of 30-60℃ / min; S3: front cover plate and composite amplitude transformer preparation, the parts are obtained by sequentially going through batching, smelting and casting, blooming and forging, drawing, cryogenic treatment, and finally finish machining, the cryogenic treatment is: -60 to -100 ℃ for 2-6 h, and air cooling; S4: working tip preparation, the base material part is obtained by sequentially going through batching, smelting and casting, forging, heat treatment and finish machining, the cylindrical array structure is formed by micro-EDM, and the working tip product is obtained by depositing a coating layer on the surface of the base material by ion sputtering using one of graphite and silver targets, the sputtering power used is 200-400 w, the negative bias voltage is -150 to -30 V, and the sputtering time is 0.5-1 h; ​ S5: ultrasonic vibration system assembly, first through the back cover on the screw conductive sheet, piezoelectric ceramic sheet and front cover, compound amplitude bar connection fixed together, and make coaxial degree within 0.02mm, then compound amplitude bar and work tip through threaded connection, finally aging treatment obtains ultrasonic dental vibration system.

5. The method of claim 4, wherein the ultrasonic dental cleaning vibration system is prepared by the steps of: The average particle size of the PZT and LaBi2FeWO9 powders is 200-400 nm.

6. The method of claim 4, wherein the ultrasonic dental cleaning vibration system is prepared by the steps of: The injection temperature of the injection molding is 120-180 ℃, and the injection pressure is 70-140 MPa.

7. The method for preparing an ultrasonic dental cleaning vibration system according to claim 4, characterized in that, The smelting and casting is a vacuum consumable arc furnace smelting method.

8. The method for preparing an ultrasonic dental cleaning vibration system according to claim 4, characterized in that, The roughing forging temperature is 950-1100 ℃, the drawing temperature is 700-850 ℃, and the drawing rate is 5-10 mm / s.

9. A method for preparing an ultrasonic dental cleaning vibration system according to claim 4, characterized in that, The aging process is: 90-120 ℃ for 1-4 h, and cooling with the furnace.

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