47results about How to "High piezoelectric constant" patented technology

The invention relates to a preparation method for a piezoelectric electret film. The method comprises the following steps: (1) spraying a polymer solution on a template with bulges for drying, and after drying, removing the template to obtain a first polymer film with concave pits; (2) combining the dried first polymer film with a second polymer film to form a cavity; (3) distributing opposite charges on the opposite surfaces in the cavity through polarization to form the piezoelectric electret film. The invention provides the piezoelectric electret film prepared through the method. The piezoelectric electret film comprises the first polymer film (1) with the concave pits, the second polymer film (3), the cavity (2) and the opposite charges, wherein the second polymer film (3) is combined with the surface with the concave pits of the first polymer film (1), and the cavity (2) is formed between the first polymer film (1) and the second polymer film (3); the opposite charges are distributed on the surfaces of the cavity through polarization. The concave pits are formed by coating the template with the bulges with the polymer solution.

The invention discloses a niobium oxide doped barium calcium zirconate titanate leadless piezoelectric ceramic powder material which is prepared through the following method comprising the steps of: weighting raw materials BaCO3, ZrO2, TiO2, CaCO3, MnO2 and Nb2O5 according to the stoichiometric ratio of elements in the chemical general formula: Ba0.85Ca0.15Ti0.895-xZr0.1Mn0.005NbxO3; carrying out ball milling on the raw materials for 10-16h by taking absolute ethyl alcohol as a medium, and drying the ball-milled slurry to obtain dry powder; and placing the dry powder into the air, and pre-sintering the dry powder at the temperature of 1100-1300 DEG C for 1-4h to obtain the niobium oxide doped barium calcium zirconate titanate leadless piezoelectric ceramic powder material. The Ba0.85Ca0.15Ti0.895-xZr0.1Mn0.005NbxO3 leadless piezoelectric ceramic with a perovskite type structure, which is obtained by using the traditional solid state sintering method and industrial raw materials, has more excellent performance. Shown by mass data statistics, the leadless piezoelectric ceramic prepared by using the niobium oxide doped barium calcium zirconate titanate leadless piezoelectric ceramic powder material disclosed by the invention has the piezoelectric constant d33 of 335pC/N, the electromechanical coupling factor kp of 39.5% and the dielectric loss of less than 2%. In addition, the niobium oxide doped barium calcium zirconate titanate leadless piezoelectric ceramic powder material is stable in preparation process and better in industrial prospect.

In a piezoelectric element comprising a first electrode 2 provided on a substrate 1, a piezoelectric material 3 provided on the first electrode 2 and a second electrode 4 provided on the piezoelectric material 3, the piezoelectric material 3 is configured so as to have a perovskite type crystal structure which is represented by a formula ABO3 and in which the main component for the A site is Pb and the main components for the B site are Zr, Ti and Pb, and configured so that a ratio of Pb atoms to all atoms in the B site is more than 3% and not more than 30%. Namely, the piezoelectric material 3 is formed so as to contain Pb excessively and the excess Pb atoms are activated to be Pb<4+> during formation of the piezoelectric material 3 and then introduced into the B site.

The invention relates to tin barium titanate calcium leadless piezoelectric ceramic with excellent piezoelectric property and good temperature stability. The tin barium titanate calcium leadless piezoelectric ceramic is characterized by comprising a material (Ba[1-x]Cax)(Ti0.95Sn0.05)O3, wherein x is 0-0.07; in a component interval of 0.01-0.06, the the piezoelectric constant d33 of the ceramic of the system is more than 4000pC/N; the electromechanical coupling coefficient kp of the the piezoelectric constant d33 is more than 41%, so the performance of the traditional piezoelectric ceramic containing lead is achieved; in addition, the piezoelectric constant d33 of the ceramic and the electromechanical coupling coefficient kp have good temperature stability; the piezoelectric constant d33 and the electromechanical coupling coefficient kp can respectively achieve over 3000pC/N and 30% when x is 0.01-0.06; and the tin barium titanate calcium leadless piezoelectric ceramic displays that the material has good application prospect.

The sensor shapes a rectangle slice with a thickness of 30-50mum. The polyvinylidene fluoride is extruded to form film. The synchronous draw polarization is made for the film, and then vacuum coating is made for it to get the sensor with piezoelectric effect for use in electronic whiteboard. The ration of drawing is 4.5:1. the polarization temperature is 65-90DEG C. The polarization electric fields 20-80MV/m. The coating material is silver and aluminum. The thickness of electrode is 50-100nm. The coating vacuum degree is 10x10-3-5 x10-7Pa. The distance between extraction electrodes is 21.6m m.

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.

The invention discloses a preparation method of preferred orientation BaTiO3/SrTiO3 nano composite ceramic. The method includes that titanic acid, barium hydroxide and strontium hydroxide are taken as raw materials, a hydrothermal method is used to optimize technical parameters, and BT and ST ceramic powder is synthesized; through testing result analysis of a scanning electron microscope, all the prepared powder is nanoscale, a green structure is formed by tape-casting lamination according to a template grain growth method, and the composite ceramic is obtained by sintering according to a specific process. Calculation results show that the ceramic has a certain orientation; the piezoelectric constant (d33) of the polarized ceramic is big, and the preferred orientation BaTiO3/SrTiO3 nano composite ceramic can be used as a leadless piezoelectric ceramic material.

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.

The invention discloses a preparation method of Fe2O3 doped with PHT-PNN piezoelectric ceramic. The preparation method comprises the following steps: (1) synthetizing prefabricated precursor nickel niobate powder; (2) proportioning according to 0.51Pb (Ti0.7Hf0.3) O3-0.49Pb (Ni1/3Nb1/3) O3 stoichiometry and doping with 0.4%-1.2% mol of Fe2O3; (3) preparing pre-synthetic powder; (4) granulating and forming embryo; (5) obtaining Fe2O3 doped with PHT-PNN piezoelectric ceramic primary products; (6) polishing, silvering and treating in a polarized mode to obtain the Fe2O3 doped with the PHT-PNN piezoelectric ceramic. The preparation method is simple and can obtain high performance piezoelectric ceramic materials with the piezoelectric coefficient greater than 900 pC/N.

The invention discloses a PZT-based piezoelectric ceramic and a preparation method thereof. In component design, at least one of CaO, BaO, SrO and MgO is doped into PZT ceramic to improve the performance of a ceramic material; and in the preparation method, weighed chemical raw materials are subjected to primary grinding by a ball mill according to a design formula, and then, drying andsieving are carried out; then, the sieved powder is subjected to radiation synthesis in a microwave oven to form presintered powder; and secondary grinding is carried out according to the ball mill method, drying and sieving are carried out, a PVA solution is added for granulating, and then, dry-pressing molding is carried out to obtain a green body; and finally, sintering and densifying are carried out in a microwave oven to obtain the PZT-based piezoelectric ceramic product. Compared with the prior art, on the basis of a traditional powder metallurgy process, and by introducing the microwave radiation synthesis superfine powder and microwave sintering technology, the method has the advantages of being excellent in comprehensive performance, environmentally friendly, high in production efficiency, capable of easily achieving batch production and the like, can well meet commercial requirements and is very suitable for preparing PZT-based piezoelectric ceramic products.

The invention discloses a piezoelectric composition, and the composition comprises an oxide having a perovskite structure, wherein the oxide contains bismuth, barium, iron and titanium; the X-ray diffraction pattern of the piezoelectric composition after a polarization treatment has a first peak and a second peak in the range of the diffraction angle 2theta of 38.6 degrees or more and 39.6 degreesor less; the diffraction angle 2theta of the first peak is smaller than the diffraction angle 2theta of the second peak; an intensity of the first peak is represented as IL; an intensity of the second peak is represented as IH; and IH/IL is 0.00 or more and 2.00 or less.

The invention relates to a preparation method of a flexible piezoelectric film. The preparation method of the flexible piezoelectric film comprises the following steps: S1, weighing raw materials; s2, weighing a solvent; s3, heating in a water bath and dissolving; s4, patterning the mixed solution on a flexible substrate by adopting a silk-screen printing, spin-coating or coating process to form a film, firstly baking for 20-60 minutes at the temperature of 40-80 DEG C, then baking for 20-60 minutes at the temperature of 80-120 DEG C, and finally annealing for 0.5-8 hours at the temperature of 120-140 DEG C to obtain a flexible piezoelectric film semi-finished product; and S5, the annealed flexible piezoelectric film semi-finished product is polarized in the air at normal temperature, the polarization voltage is 10-35 MV/cm, the time is 1-60 min, and a flexible piezoelectric film finished product is obtained. The piezoelectric film with the high piezoelectric constant is prepared through the mixed solvent with the high boiling point and the low boiling point, and the requirement of a piezoelectric film sensor for the piezoelectric constant is met.

The invention discloses potassium-sodium niobate-based leadless piezoelectric ceramic with a high piezoelectric constant. The chemical composition of the potassium-sodium niobate-based leadless piezoelectric ceramic with the high piezoelectric constant is (1-x)(K<0.5>Na<0.5>)Nb<1-y>Sb<y>O<3>+xCuZr<0.5>Ti<0.5>O<3>, x and y are mole percentages, 0<=x<=0.4, and 0.01<=y<=0.2. According to the potassium-sodium niobate-based leadless piezoelectric ceramic with the high piezoelectric constant and the preparation method thereof, doping modification is carried out by adopting copper, antimony, zirconium and titanium elements, so that charge and vacancy compensation is realized, the piezoelectric constant is improved, and the piezoelectric sensitivity of the leadless piezoelectric ceramic is improved. The potassium-sodium niobate-based leadless piezoelectric ceramic adopted by the invention has a high piezoelectric constant, the application scene of the leadless piezoelectric ceramic is greatlybroadened, and meanwhile, the leadless piezoelectric ceramic is green and environment-friendly, so that the damage to human health and the environment can be effectively reduced.

The invention discloses a preparation process of a high-performance piezoelectric ceramic. The process comprises the following steps of (1) taking a piezoelectric ceramic raw material; (2) charging the piezoelectric ceramic raw material into a ball milling tank for sufficient mixing and ball milling; then, putting the slurry obtained after the ball milling into a drying box to be dried so as to obtain powder; (3) adding water into powder; then, adding any one or several kind of materials inof ammonium hydroxide, lemon acid or oxalic acid or a composition of several kinds of materials from ammonium hydroxide, lemon acid or oxalic acid; then, performing heating for hydrothermal treatment; drying the powder after the hydrothermal treatment; obtaining to obtain the piezoelectric ceramic raw material powder; (4) treating the piezoelectric ceramic raw material powder obtained in step (3) by a conventional piezoelectric ceramic treatment process to obtain the high-performance piezoelectric ceramic. The preparation process has the characteristics that the prepared piezoelectric ceramic has good performance; the raw material consumption is low; the cost is low; the pollution is low; the process is simple; the process stability is high.