98results about How to "Piezoelectric constant" patented technology

The invention relates to a titanium acid barium based piezoelectric ceramic material which uses titanium dioxide and barium carbonate as initial raw materials to produce tetragonal barium carbonate based powder through milling and pre-sintering solid phase reaction. The particle average size of the powder is at submicron grade, and the crystal structure of the powder is tetragonal. Then the titanium acid barium based piezoelectric ceramic material is produced, which is provided with a microstructure, the average size of the middle grain particle diameter of which is 0.2-7.5 Mu m, and the piezoelectric performance index d33 value of which is larger than 225pC/N. the barium titanate based piezoelectric ceramic material of the invention has the characteristics of low production cost, large piezoelectric constant d33 value and high planar electromechanical coupling factor kp value, can be applied to various electronic components and devices of sensors, drivers, ultrasonic transducers, resonators, filters, buzzers, electronic igniters, etc. and can be used as lead-free piezoelectric ceramic to substitute lead bearing PZT piezoelectric ceramic material which is widely applied currently.

The invention relates to a low-temperature cofiring multilayer piezoelectric ceramic. The main material composition is as follows: yPb(ZrxTi(1-x))O3-(1-y-z)Pb(Mn1/3Sb2/3)O3-zPb(Zn1/3Nb2/3)O3, in addition, a proper amount of CuO is added as a fluxing agent to realize multilayer film low-temperature sintering, wherein the x value accounts for 0.40%-0.60%, the y value accounts for 0.60%-0.88%, the z value accounts for 0.02%-0.1%, and the weight percentage of CuO is 0%-0.05%. A multilayer film is prepared by adopting a tape casting method; the high-density multilayer piezoelectric ceramic is obtained by carrying out glue arrangement between 110 DEG C and 500 DEG C and carrying out low-temperature sintering at 830-850 DEG C; the appearance d33 of the piezoelectric multilayer film ceramic with a three-layer structure is more than or equal to 875 Pc/N by being tested through pressure point property and is far more than the d33 value (306 Pc/N) of a single-layer ceramic with same components. The low-temperature cofiring multilayer piezoelectric ceramic disclosed by the invention realizes the low-temperature sintering, prevents the problem of environment pollution caused by the high energy consumption, high cost, component deviation and PbO volatilization of high-temperature sintering, is excellent in piezoelectric property, achieves the d33 more than or equal to 875 Pc/N, the dielectric constant at 3000-6000 and the electromechanical coupling coefficient K31 more than or equal to 0.56 and meets the requirements of a multilayer piezoelectric ceramic device.

Disclosed is a method for preparing texture piezoelectric ceramic film wherein the major chemical composition of the ceramics is Pb(Mg1/3Nb2/3)O3-xPbTiO3, x=0.429-0.538, containing 3-20 wt% (001) oriented sheet-like SrBi4Ti4O15 formwork material, and having the shape of (001) oriented sheet-like SrBi4Ti4O15. The preparation process comprises charging Pb(Mg1/3Nb2/3)O3-xPbTiO3 powder into the mixed solvent of anhydrous alcohol and methyl ethyl ketone, charging dispersing agent simultaneously, mixing and ball milling, then charging SrBi4Ti4O15 formwork material, charging binding agent and plasticizing agent simultaneously, mixing and ball milling again, de-soaking the obtained slurry and doctor-blade casting, drying, laminating and press forming, subjecting the samples to isostatic cool pressing and plastic-discharging at elevated temperature, immersing in polyvinyl alcohol aqueous solution and pressurizing again, thermally pressing and sintering at the presence of argon atmosphere, and sintering in the atmosphere of air atmosphere, the prepared textured piezo-electric ceramics has higher piezoelectric constant.

The invention provides a potassium niobate sodium-based multi-layer piezoelectric ceramic element. A chemometry general form of a formula of potassium niobate sodium-based leadless piezoelectric ceramics is that [(Na0.52K0.44)1-xLix] (Nb0.93-ySb0.07Tay)O3, wherein 0.02<=x<=0.06, 0.02<=y<=0.06, a piezoelectric constant ranges from 300 pC/N to 350 pC/N and even higher, a dielectric constant ranges from 1700 to 2000, and an electromechanical coupling coefficient ranges from 0.40 to 0.45.

The invention discloses a piezoelectric ceramic material and a preparation method thereof. The general chemical formula of the piezoelectric ceramic material is shown in the specification, (0.96-X)K<0.48>Na<0.52>Nb<0.95>Sb<0.05>O<3>-0.04Bi<0.5>(Na<0.82>K<0.18>)<0.5>ZrO<3>-0.4%Fe2O3-xRSbO3, wherein the R is an alkali metal element, the x is the molar percentage of antimonate RSbO3, and the x is greater than or equal to 1.4% and less than or equal to 2.5%. The piezoelectric ceramic material provided by the embodiment of the invention has a relatively high piezoelectric constant and a relativelyhigh planar electromechanical coupling coefficient, and has a wide application range. In addition, the piezoelectric ceramic material provided by the embodiment of the invention does not contain a lead element, belongs to an environment-friendly material, conforms to the sustainable development strategy in the current international social development, and is beneficial to environmental protection.

The invention discloses a composite piezoelectric film and a preparation method thereof. The pure natural plant nano cellulose fiber, Mxene and polyvinylidene fluoride are used as raw materials, and anano cellulose/PVDF composite film with stronger piezoelectric property is prepared by the processes of mechanical mixing, drying film formation, high-voltage polarization and the like. The production cost is low, and the process is simple; the product is good in flexibility, high in sensitivity, suitable for batch production and continuous production, high in piezoelectric constant and high in environmental adaptability, and has great application potential in the fields of medical care, sports and leisure, human-computer interaction, transportation and the like.

The invention relates to a potassium-sodium niobate based lead-free piezoceramic-polyvinyl alcohol (PVA) piezoelectric composite material and a preparation method thereof. The preparation method comprises the following steps: mixing materials according to a formula (1-x)(LiaNabK1-a-b)(Nb1-cSbc)O3-xABO3-yM, adopting analytical pure anhydrous carbonate or oxide as the raw material, and using the traditional ceramic preparation technique to prepare ceramic powder; mixing the ceramic powder and polyvinyl alcohol into mixed powder according to a volume ratio of 5/90 to 95/5, adding deionized waterto the mixed powder and heating to dissolve the PVA; and then carrying out ultrasonic dispersion, drying the mixed powder, then conducting cold-pressing and forming by a sheet-pressing machine, then using a muffle furnace for heating treatment, finally sputtering metal electrodes on the surface thereof, carrying out silicon oil bath for polarization, finally obtaining the potassium-sodium niobatebased lead-free piezoceramic-polyvinyl alcohol piezoelectric composite material. The piezoelectric composite material is pure perovskite crystal phase, has no mixed phase and has good piezoelectric performance and dielectric property.

The invention provides low-temperature sintering lithium antimoniate mixed quinary system piezoelectric ceramics, which consists of the materials expressed with the following general expression: 0.02Pb(Mg1/2W1/2)O3-yPb(Sb1/2Nb1/2)O3-(0.39-y)Pb(Ni1/3Nb2/3)O3-Pb0.59(Zr0.38Ti0.21)O3+xLiSbO3. In the general expression, x is more than 0 percent by weight, but less than 0.40 percent by weight; y is more than or equal to 0 percent by weight, but less than or equal to 0.030mol. The preparation method of the lower-pressure sintering lithium antimoniate mixed quinary system peizoelectric ceramics comprises the processing steps of preparing lithium antimoniate, synthesizing ingredients, pre-burning, granulation, tabletting, batching-out, sintering, burning silver and polarization. According to the laboratory investigation result, the piezoelectric constant and the planar electromechanical coupling factor of the quinary system piezoelectric ceramics prepared are high; the low-temperature sintering performance is good. By comparing the low-temperature sintering antimoniate mixed quinary system with similar piezoelectric ceramics reported in literatures, the mechanical quality factor Qm and the dielectric loss tan Delta are significantly reduced; the piezoelectric constant d33 and the planar electromechanical coupling factor Kp are significantly improved; the sintering temperature is significantly reduced from 1200 DEG C to 900 DEG C; and the preparation process is simple with high repetitiveness, yield and low cost.

The invention discloses a synthesis method of SrTiO3 heterogeneously coated BaTiO3 ultrafine nano-powder. According to the invention, BaTiO3 nano-particles are synthesized with a sol precipitation method; SrTiO3 is subjected to secondary nucleation with a hydrothermal method, such that a coating layer is formed; and the SrTiO3 heterogeneously coated BaTiO3 ultrafine nano-powder is synthesized. With the method provided by the invention, the synthesized nano-particles have small particle size, good dispersion and a significant core-shell structure. Also, because BaTiO3 and SrTiO3 have different interplanar spacings, the two are subjected to lattice distortion at contact interface layers, such that the dielectric constant and piezoelectric constant of BaTiO3 are improved. With the change of the doping amount of Sr, the interplanar spacings of heterojunction show a regular change.

The invention relates to a doping type tantalic acid gallium-lanthanum crystal for high-temperature piezoelectric devices and a preparation method of the doping type tantalic acid gallium-lanthanum crystal. The general formula of the doping type tantalic acid gallium-lanthanum (M-LGT) crystal is y%M: La3Ta0.5+xGa5.5-xO14, wherein x is larger than or equal to -0.3 and smaller than or equal to 0.3, y is larger than or equal to 3.0 and smaller than or equal to 2, and a doping element M is at least selected from one of Ba, Mo and Al. The crystal can be prepared through adopting crystal growing methods such as a czochralski method and a bridgeman-stockbarger method, and the electrical resistivity of the crystal at high temperature can be obviously increased through optimizing growing atmosphere, doping elements and post treating. A piezoelectric element which is produced by the crystal is firstly and successfully applied to a high-temperature piezoelectricity acceleration sensor of -200 DEG C-649DEG C, and the doping type high-electrical resistivity LGT crystal material has a bright application prospect in future piezoelectric devices.

The invention discloses bismuth ferrite-lead titanate-barium titanate ternary-system high-temperature piezoelectric ceramics and a preparation method thereof. The BF-PT-BT high-temperature piezoelectric ceramics have the advantages that the BF-PT-BT high-temperature piezoelectric ceramics are prepared through a solid reaction process, so that insulation performance of a BF-PT material is improved remarkably through introduction of a third component BT into a BF-PT solid solution; a piezoelectric constant of the BF-PT-BT high-temperature piezoelectric ceramics is as high as 195 pC/N, the Curie temperature thereof is as high as 547 DEG C, and the piezoelectric performance thereof can be kept sable relatively at the temperature lower than 490 DEG C; the BF-PT-BT high-temperature piezoelectric ceramics are approximate to a piezoelectric material of a commercial bismuth layer structure in Curie temperature but are 4 times greater than that in piezoelectric coefficient.

The invention discloses a ternary piezoceramic material with high Curie temperature and a preparation method thereof. The piezoceramic material has a chemical formula of (1-y)((1-x)BF-xPT)-yPMN, wherein 0<y<0.1 and 0.2<x<0.4. A third component of plumbum manganese niobate (PMN) is introduced into a bismuth ferrite-plumbum titanate (BF-PT) system for the first time to form a ternary solid solution system. The characteristic of high Curie temperature of the BF-PT material itself is effectively used, and the introduction of the third component of PMN significantly improves the insulating property of the BF-PT material, which enables the BF-PT-PMN material of the invention to be easily polarized to obtain a high piezoelectric constant. The novel ternary piezoceramic material with high Curie temperature of the invention can prepare high temperature piezoelectric ceramics with a Curie temperature of up to 620 DEG C and a piezoelectric constant of up to 90 pC/N, and when compared with high temperature piezoelectric ceramics prepared in an US patent of Xiaoli Tan in 2013, the prepared high temperature piezoelectric ceramics have more excellent performance with not only a Curie temperature increased by nearly 50 DEG C, but also a piezoelectric constant increased by 26 pC/N. With the material and the method of the invention, application of BF-PT based materials in the high temperature piezoelectric field takes a big step forward.

A monolithic piezoelectric part capable of yielding a high piezoelectric d constant and suppressing reduction in reliability such as deterioration in insulation resistance can be obtained by a method for manufacturing a monolithic piezoelectric part wherein a piezoelectric ceramic body is formed of a perovskite compound oxide expressed by the general formula of ABO₃, and the molar quantity of the A site component, Pb, is reduced by about 0.5 mol % to 5.0 mol % from that of the stoichiometric composition, ceramic raw materials are combined so that the average valence of the B site component is greater than quadrivalent, which is the same as the stoichiometric composition, to synthesize the ceramic powdered raw material, which is processed subsequently to fabricate a layered article, and the layered article is subjected to sintering processing within an atmosphere wherein the oxygen concentration is about 5% or less but more than 0% by volume.

The invention provides a piezoelectric ceramic intelligent structure and a method for embedding the piezoelectric ceramic intelligent structure into a metal matrix. The piezoelectric ceramic intelligent structure provided by the invention comprises a piezoelectric ceramic spherical shell, wherein the middle of the piezoelectric ceramic spherical shell is provided with a spherical metal inner coreserving as an internal electrode, the outer surface of the piezoelectric ceramic spherical shell is provided with a metal coating serving as an external electrode, the outer surface of the piezoelectric ceramic spherical shell is subjected to electrode segmentation to form pressure sensor arrays arranged at equal intervals, and the piezoelectric ceramic spherical shell is internally provided witha lead channel used for leading out the internal electrode. According to the piezoelectric ceramic spherical array structure with the spherical metal inner core, piezoelectric ceramic has a high piezoelectric constant and Young modulus compared with piezoelectric fibers, and the reaction speed is high. The structure is uniform in spatial directivity, can focus and sense signals by 360 degrees, andcan be used as a signal receiver and a signal generator at the same time.

The invention relates to a bismuth ferrite-based piezoelectric ceramic material with high depolarization temperature and high piezoelectric property, and a preparation method thereof, wherein the general chemical formula of the bismuth ferrite-based piezoelectric ceramic material is (1-x)(0.725BiFeO3-0.275BaTiO3)-xPbTiO3+0.8 mol% MnO2, and x is greater than or equal to 0.1 and less than or equal to 0.3. The preparation method comprises the following steps: mixing all metal oxide raw materials, sequentially carrying out ball milling, drying and presintering, mixing with a manganese source, carrying out secondary ball milling and drying, mixing with PVA, granulating, and carrying out compression molding to obtain a ceramic green body; and finally carrying out rubber discharging and sinteringon the ceramic green body to obtain the bismuth ferrite-based piezoelectric ceramic material. Compared with the prior art, the bismuth ferrite-based piezoelectric ceramic material disclosed by the invention has the advantages that the preparation method is simple, economic, practical and the like, and the prepared bismuth ferrite barium titanate-based piezoelectric ceramic has high Curie temperature, excellent temperature stability and relatively high piezoelectric constant, and shows a wide industrial application prospect.

The invention discloses a high-performance piezoelectric ceramic and a preparation method thereof. The chemical general formula is Pb<n>Sr<m>(Mg<1/3>Nb<2/3>) Zr<y>Ti<x>O<3>+g%CeO<2>+h%PbO+b%CuO+d%Nb<2>O<5>, in the formula, 0.927 < = n < = 0.976, 0.024 < = m < = 0.073, 0.25 < = z < = 0.25, 0.35 < = y < = 0.35, 0.50 < = x < = 0.60, 0.4<=g<=0.7, 0.1<=h<=0.3, 0.1<=b<=0.3, 0.1<=d<=0.3. According to thepreparation method, Pb(Mg<1/3>Nb<2/3>)O<3> is synthesized, and adding into a PZT system is adopted to realize high intensity. The prepared product is high in density, high in power, high in efficiency, and high in quality. The piezoelectric ceramic is a modified hard PZT system piezoelectric ceramic, has high power bearing capacity and high comprehensive performance, can meet the requirements ofpeople, is extremely suitable for power type transducers with extremely high power and high driving requirements, and can be widely applied to sensors with extremely high power requirements such as high-power sound wave welding and fishery group detection.

The invention discloses a piezoelectric optoelectronic material for the degradation of organic pollutants. The piezoelectric optoelectronic material utilizes two-dimensional KNbO3 nanosheets. A preparation method of the two-dimensional KNbO3 nanosheet comprises orderly adding KOH and Nb2O5 into a container with ethylene glycol according to the ratio, carrying out full dispersion, transferring themixed solution into a high pressure reactor, carrying out heating for some time, carrying out cooling to the room temperature, carrying out cleaning and drying to obtain a white product, grinding thewhite product into powder, and carrying out calcination at a high temperature to obtain the two-dimensional KNbO3 nanosheet. The invention also provides an organic pollutant degradation method. The method utilizes the piezoelectric optoelectronic material as a catalyst, and ultrasonic wave or combination of illumination and ultrasonic waves to assist in the degradation of organic pollutants. The piezoelectric optoelectronic material fully utilizes the two-dimensional KNbO3 nanosheet advantages of a large ratio of the active exposed surface, a strong adsorption capacity, easy deformation and high piezoelectric constant, can be used as a photocatalyst to be excited by ultraviolet light, can excite more electron hole pairs under ultrasonic conditions through the piezoelectric effects and realizes the efficient removal of organic pollutants.

The invention belongs to the technical field of piezoelectric materials, and particularly relates to a composite piezoelectric film and a preparation method and application thereof. The preparation method comprises the following steps: adding inorganic piezoelectric powder into a polymer solution to obtain a precursor solution; and carrying out electrostatic spinning on the precursor solution andperforming collection in a water medium to obtain the composite piezoelectric film. The composite piezoelectric film is a porous structure fiber film and is filled with inorganic piezoelectric powder,and a polymer piezoelectric material and a rigid piezoelectric material are well compounded. Moreover, the composite piezoelectric film is a beta-phase enhanced flexible composite film, can generatea relatively large output piezoelectric voltage, has a relatively high piezoelectric constant, is uniform in piezoelectric effect distribution, and can solve the problem that an existing polymer piezoelectric film cannot be effectively combined with an inorganic piezoelectric material to form a flexible device with high piezoelectric performance. In addition, the preparation method is simple in preparation process and beneficial to large-scale production.