A kind of PZT piezoelectric fabric and preparation method thereof
Technical field
The present invention relates to the functionality ceramic fiber art, be specially a kind of novel lead zirconate titanate (PZT) piezoelectric fabric and manufacture method thereof.
Background technology
Piezoelectric fabric has very big potential application because of having excellent properties such as higher piezoelectric strain constant and thickness electromechanical coupling coefficient, low mechanical quality factor and acoustic impedance in fields such as sensor, driver, ultrasonic sensing apparatus and automobile, aviations.At present, the preparation method of piezoelectric fabric mainly comprises: sol-gal process, suspension magnetic spin processes and thermoplastic polymer method.United States Patent (USP) U.S.Pat.No.4921328 and German R.Harsch etc. have adopted Prepared by Sol Gel Method PZT fiber, diameter is at 50-150 μ m, its weak point is this method because solid concentration is low, the piezoelectric fabric internal structure of preparation forms tangible nucleocapsid structure, skin is very fine and close, and there is more space inside, causes the fiber uniformity to descend, and the bad control of fiber shape, thereby cause that piezo-electric effect obviously descends.U.S. Advanced Cerametrics company adopts suspension magnetic spin processes to prepare the PZT fiber of cross dimension at 80~300 μ m, but because this method uses a large amount of organic polymers as carrier, in pyrolysis and sintering process, high molecular volatilization can produce micropore.In addition, the viscosity of suspended substance is bigger, is difficult to the less fiber of control diameter.Wait quietly adopting the thermoplastic polymer legal system to be equipped with the PZT ceramic fibre that diameter is 300 μ m in week, the deficiency of this method is to add a certain amount of polyvinyl alcohol (PVA) in the polymer, stays part micropore and ash content at fibrous inside during binder removal, causes the fiber density to descend.
Summary of the invention
The present invention provides a kind of PZT piezoelectric fabric and preparation method thereof in order to solve the deficiency that above-mentioned prior art exists.
The technical scheme that the present invention solve the technical problem is: a kind of PZT piezoelectric fabric, be by colloidal sol-admixture of powder extrusion molding preparation, specifically be to be evenly to mix in 1: 1~1: 9 by mass ratio with colloidal sol and PZT powder, then mixture is extruded the fiber of certain diameter under on the extruder 60 ℃, dry back sintering obtains the PZT piezoelectric fabric; Comprise lead acetate, zirconium nitrate, butyl titanate, water, acetic acid in the wherein said colloidal sol, the concentration of colloidal sol is 0.3mol/l, and the mass ratio of lead acetate, zirconium nitrate, butyl titanate is 110: 56: 44, and the volume ratio of water and acetic acid is 1: 0.5~1: 3.
The preparation method of the piezoelectric fabric of the said PZT of the present invention, it is characterized in that, be evenly mixing in 1: 1~1: 9 with colloidal sol and PZT powder by mass ratio, then mixture extruded the fiber of certain diameter under on the extruder 60 ℃, dry back sintering obtains the PZT piezoelectric fabric; Comprise lead acetate, zirconium nitrate, butyl titanate, water, acetic acid in the wherein said colloidal sol, the concentration of colloidal sol is 0.3mol/l, and the mass ratio of lead acetate, zirconium nitrate, butyl titanate is 110: 56: 44, and the volume ratio of water and acetic acid is 1: 0.5~1: 3.
The preparation method of PZT piezoelectric fabric of the present invention follows these steps to carry out:
(1) PZT colloidal sol preparation: with mass ratio is that 110: 56: 44 lead acetate, zirconium nitrate, butyl titanate carries out ultrasonic dissolution respectively in organic solvent, and add an amount of stabilizing agent, three's precursor solution is mixed, under 80 ℃ of low-temperature heats and sonic oscillation condition, add volume ratio therein and be 1: 0.5~1: 3 water and acetic acid regulator solution degree of hydrolysis, the concentration of adjusting colloidal sol is 0.3mol/l, and under magnetic agitation mixture is mixed, and obtains described colloidal sol;
(2) preparation of colloidal sol-powder system: is mixing in 1: 1~1: 9 with colloidal sol and PZT powder by mass ratio, 80 ℃ of low-temperature heats with under evenly stirring, utilize mortar to grind again several minutes, or be rolled with roll forming machine, make mixture fully mix, and have suitable plasticity;
(3) preparation of PZT piezoelectric fabric: above-mentioned (2) gained moldable mixture is placed suitable preheated mold, under certain pressure and 60 ℃ of low-temperature heats, on extruder, carry out the preparation of cellulose base, the fiber biscuit is placed on drying at room temperature on the plate glass, gets rid of the adsorbed water of fiber surface;
(4) heat treatment of PZT piezoelectric fabric: with the fiber after the drying at room temperature, in the low temperature drying case, carry out drying, heat-treat then, obtain the PZT piezoelectric fabric.
In the manufacture method of PZT piezoelectric fabric of the present invention, solvent and stabilizing agent are organic matter commonly used, solvent such as glycol monoethyl ether, ethylene glycol ethyl ether, ethylene glycol, stabilizing agent such as acetylacetone,2,4-pentanedione, polyacrylic acid, Sodium Polyacrylate etc. in the described colloidal sol.
In the manufacture method of the novel PZT piezoelectric fabric of the present invention, in the described colloidal sol powder systems, powder is PZT powder commonly used, as PZT5, and Zr: Ti=56 wherein: 44.
In the manufacture method of PZT piezoelectric fabric of the present invention, described water and acetic acid ratio are 1: 0.5~1: 3, but water and acetic acid ratio be 1: 0.65~1: 1.5 o'clock be ideal range, if ratio is excessive, then owing to the too high levels of water, the hydrolysis rate of colloidal sol is very fast, can form gel and lose plasticity; Otherwise, ratio is too small, the too high levels of acetic acid, though help suppressing the carrying out of hydrolysis, in dry and the process of burning till, acetic acid can volatilize, enlarged the contraction of fiber, also stay a large amount of pores simultaneously, reduced the density and the intensity of fiber, therefore required the ratio of water and acetic acid in described scope.
In the manufacture method of PZT piezoelectric fabric of the present invention, described colloidal sol and PZT powder ratio are 1: 1~1: 9, and solid concentration has reached 50%~90%, desired proportions was at 1: 4~1: 8, and when ratio was excessive, solid concentration was lower, mixture is in the rheology attitude, and viscosity is low excessively, can not form fiber, even it is also yielding to form fiber, otherwise ratio is low excessively, and mixture has lost plasticity, can't extrude continuously long fiber uniformly, therefore, require the ratio of colloidal sol and PZT powder in described scope.
In the manufacture method step (3) of PZT piezoelectric fabric of the present invention, the pressure of extruding is conventional, preferred 5~20MPa.Adopt 60 ℃ of low temperature to mold heated, purpose is the plasticity that improves the rate of extrusion of fiber and keep mixture,
The manufacture method step (4) of PZT piezoelectric fabric of the present invention specifically can be: with the fiber after the drying at room temperature, carry out drying in 80~100 ℃ of drying boxes, be arranged in then on the flat ceramic sheet, sprinkle leaded atmosphere material on every side, cover, heat-treat with crucible.
Concrete heat treatment process is: 1. room temperature~200 ℃, and 1 ℃/min of heating rate, 200 ℃ of insulation 1h mainly are the volatilizations of moisture and partial organic substances in the fiber presoma; 2.200~600 ℃, 2 ℃/min of heating rate, 600 ℃ are incubated 1~2h, are mainly the crystallization of organic volatilization and decomposition and PZT fiber; 3.600 ℃~sintering temperature, 200 ℃/h of heating rate is mainly grain growth, the discharge of fiber densification and pore, insulation 2h.
Compare with prior preparation method, outstanding advantage of the present invention: employing PZT colloidal sol replaces the organic binder bond in traditional sol-gal process, therefore avoided fiber in dry and binder removal process, to cause staying micropore after the distortion of fiber and the organic binder bond eliminating, thereby improved the density of fiber biscuit, reduce the shrinkage factor of fiber, improved the contraction distortion of fiber.Secondly, the present invention adopts colloidal sol-admixture of powder extrusion molding technology, and this method has been improved in traditional extrusion molding and added large amount of organic, causes the defective of the fiber bending distortion of extruding, simultaneously the accurate shrinkage factor of diameter, length and the fiber of controlling fiber.PZT piezoelectric fabric of the present invention is to have single perovskite phase structure, the density height, and fiber is smooth, and diameter 80~1000 μ m have high piezoelectric property, can be used for the PZT piezoelectric fabric of sensing/driving element 1-3 piezoelectric fibre composite material.
Description of drawings
Fig. 1 is the X-ray diffraction spectrogram of PZT piezoelectric fabric at 1240 ℃ of sintering.Abscissa is the angle of diffraction among Fig. 1, and ordinate is a diffracted intensity.
Fig. 2 is the sem photograph of PZT piezoelectric fabric section at 1240 ℃ of sintering.
The specific embodiment
Employed in the present invention term unless other explanation is arranged, generally has the implication of those of ordinary skills' common sense.
Below in conjunction with specific embodiment, and comparable data is described the present invention in further detail.Should be understood that these embodiment just in order to demonstrate the invention, but not limit the scope of the invention by any way.
In following embodiment, various processes of Xiang Ximiaoshuing and method are not conventional methods as known in the art.The source of agents useful for same, trade name and be necessary to list its constituent person indicate when occurring first that all used thereafter identical reagent if no special instructions, and is all identical with the content of indicating first.
Embodiment 1:
(1) gets 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, spent glycol monomethyl ether uniform dissolution is mixed, add 1: 0.65 water of volume ratio and acetic acid and a small amount of acetylacetone,2,4-pentanedione and make stabilizing agent, adjusting solution concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol
(2) by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 4,80 ℃ of low-temperature heats with under evenly stirring, utilized mortar to grind again several minutes, or was rolled with roll forming machine, made mixture fully mix, and had suitable plasticity;
(3) preparation of PZT piezoelectric fabric: above-mentioned (2) gained moldable mixture is placed suitable preheated mold, under 5~20MPa pressure and 60 ℃ of low-temperature heats, on extruder, carry out the preparation of cellulose base, the fiber biscuit is placed on drying at room temperature on the plate glass, gets rid of the adsorbed water of fiber surface;
(4) heat-treat after the drying, burn till, obtain the PZT piezoelectric fabric at 1200 ℃.
After measured, the density of piezoelectric fabric is 6.1g/cm
3, radial shrinkage ratio is 17.4%.
Embodiment 2:
Get 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, spent glycol ether uniform dissolution is mixed, add 1: 1 water of volume ratio and acetic acid and a small amount of polyacrylic acid and make stabilizing agent, adjusting solution concentration concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol, by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 5, evenly be mixed with to have plastic colloidal sol powder systems.Extrude the fiber of certain diameter under on the extruder 60 ℃, burn till at 1240 ℃ dry back, obtains dried fibres, and after measured, the density of piezoelectric fabric is 6.4g/cm
3, radial shrinkage ratio is 17.1%.
Embodiment 3:
Get 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, spent glycol monomethyl ether uniform dissolution is mixed, add 1: 0.5 water of volume ratio and acetic acid and a small amount of Sodium Polyacrylate and make stabilizing agent, adjusting solution concentration concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol, by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 1, evenly be mixed with to have plastic colloidal sol powder systems.Extrude the fiber of certain diameter under on the extruder 60 ℃, burn till at 1200 ℃ dry back, obtains dried fibres.After measured, the density of piezoelectric fabric is 6.7g/cm
3, radial shrinkage ratio is 18%.
Embodiment 4:
Get 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, the spent glycol uniform dissolution is mixed, add 1: 1.5 water of volume ratio and acetic acid and a small amount of acetylacetone,2,4-pentanedione and make stabilizing agent, adjusting solution concentration concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol, by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 6, evenly be mixed with to have plastic colloidal sol powder systems.Extrude the fiber of certain diameter under on the extruder 60 ℃, burn till at 1200 ℃ dry back, obtains dried fibres.After measured, the density of piezoelectric fabric is 6.9g/cm
3, radial shrinkage ratio is 17.0%.
Embodiment 5:
Get 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, spent glycol monomethyl ether uniform dissolution is mixed, add 1: 3 water of volume ratio and acetic acid and a small amount of Sodium Polyacrylate and make stabilizing agent, adjusting solution concentration concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol, by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 9, evenly be mixed with to have plastic colloidal sol powder systems.Extrude the fiber of certain diameter under on the extruder 60 ℃, burn till at 1240 ℃ dry back, obtains dried fibres.After measured, the density of piezoelectric fabric is 7.3g/cm
3, radial shrinkage ratio is 16.0%.
Embodiment 6:
Get 20 parts of 110: 56: 44 lead acetates of mass ratio, zirconium nitrate, butyl titanate, spent glycol monomethyl ether uniform dissolution is mixed, add 1: 1.5 water of volume ratio and acetic acid and a small amount of acetylacetone,2,4-pentanedione and make stabilizing agent, adjusting solution concentration concentration under the magnetic agitation effect is 0.3mol/l, obtain colloidal sol, by colloidal sol: the PZT powder quality took by weighing 80 parts of PZT powder than 1: 8, evenly be mixed with to have plastic colloidal sol powder systems.Extrude the fiber of certain diameter under on the extruder 60 ℃, burn till at 1240 ℃ dry back, obtains dried fibres, its X-ray diffraction spectrogram as shown in Figure 1, display fibers has single perovskite phase; PZT piezoelectric fabric section is at the sem photograph (Fig. 2) of 1240 ℃ of sintering, and fiber cross-section morphology display fibers is comparatively fine and close among the figure, pore-free.After measured, the density of piezoelectric fabric is 7.3g/cm
3, radial shrinkage ratio is 15.8%.