CN115521140B - Pyrophosphate solid solution porous ceramic and preparation method and application thereof - Google Patents
Pyrophosphate solid solution porous ceramic and preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a pyrophosphate solid solution porous ceramic, a preparation method and application thereof. A method for preparing pyrophosphate solid solution porous ceramics, which comprises the following steps: zrO (ZrO) 2 、HfO 2 、TiO 2 Respectively presintering the powder, mixing the presintered powder with phosphoric acid for mixing reaction, and performing centrifugal treatment to obtain solid high-temperature sintering to obtain pyrophosphate solid solution ceramic compact powder; mixing a binder, water and a foaming agent to obtain a mixed solution, and mixing the mixed solution with pyrophosphate solid solution ceramic powder for foaming to obtain ceramic slurry; and (3) injection molding, freeze drying and forming the ceramic powder, and sintering to obtain the pyrophosphate solid solution porous ceramic. The invention is implemented by using ZrP 2 O 7 The Zr lattice point position in the phase is introduced with two high temperature resistant metal elements Ti and Hf, and the pyrophosphate solid solution porous ceramic prepared by the foaming method has lower dielectric constant and lower heat conductivity coefficient compared with the single-component pyrophosphate porous ceramic.
Description
Technical Field
The invention belongs to the field of materials, and particularly relates to a pyrophosphate solid solution porous ceramic, and a preparation method and application thereof.
Background
The radome wave-transmitting material has important significance for development of hypersonic aircrafts, and rapid development of hypersonic aircrafts brings strict requirements to performances such as high-temperature bearing, high-temperature wave transmission, high-temperature ablation and the like of the radome material. In the phosphate wave-transmitting material, the application temperature of the aluminum-chromium phosphate system material is low, the high-temperature mechanical property is low, the matrix brittleness is large, the structure is porous, the sintering is difficult, and particularly, the hygroscopicity is strong and the moisture absorption is easy, so the requirement for developing a novel high-temperature-resistant and ablation-resistant wave-transmitting material is urgent. Zirconium phosphate system is widely focused in recent years as an emerging wave-transparent material, zirconium pyrophosphate ceramic is good in performance in dielectric property test as a porous material or a compact ceramic material, and shows thatThe thermodynamic performance and stability are excellent. The prior art of designing and preparing the sandwich structure radome material and the broadband wave-transmitting performance (Fa is strong) researches the synthesis of zirconium phosphate powder and the normal pressure sintering preparation process of zirconium phosphate ceramics, and the result shows that ZrP 2 O 7 The powder has better thermal stability before 1500 ℃; in addition, magnesium oxide is selected as sintering auxiliary agent, and the density of 2.80-2.98g/cm can be obtained by normal pressure sintering 3 When the sintering temperature exceeds 1250 ℃, the density of the sample does not change greatly with the temperature; with the increase of MgO content, the density and the bending strength of the ceramic are increased and then reduced, the maximum bending strength can reach 126MPa, but the dielectric constant is larger and is 6.0-8.5, and the zirconium pyrophosphate porous ceramic in the prior art still has the problem of larger dielectric constant.
Disclosure of Invention
In order to overcome the problem of larger dielectric constant of the pyrophosphate porous ceramic in the prior art, one of the purposes of the invention is to provide a pyrophosphate solid solution porous ceramic, the other purpose of the invention is to provide a preparation method of the pyrophosphate solid solution porous ceramic, and the other purpose of the invention is to provide application of the pyrophosphate solid solution porous ceramic.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the first aspect of the invention provides a method for preparing pyrophosphate solid solution porous ceramics, which comprises the following steps:
(1) ZrO (ZrO) 2 、HfO 2 、TiO 2 Respectively presintering the powder, mixing the mixed powder with phosphoric acid for reaction, washing and centrifuging; sintering the solid obtained after centrifugation to obtain pyrophosphate solid solution ceramic powder;
(2) Mixing a binder, water and a foaming agent to obtain a mixed solution, and then mixing the mixed solution with the pyrophosphate solid solution ceramic powder in the step (1) for foaming to obtain slurry;
(3) And (3) injecting the slurry obtained in the step (2) into a mould, freeze-drying and forming, and sintering the formed blank to obtain the pyrophosphate solid solution porous ceramic.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (1), zrO 2 、HfO 2 、TiO 2 The mass ratio of (1-2): (2-3) 1; further preferably, zrO 2 、HfO 2 、TiO 2 The mass ratio of (1.3-1.8): (2.3-2.8): 1; still further preferred, zrO 2 、HfO 2 、TiO 2 The mass ratio of (1.5-1.6): (2.5-2.7):1.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (1), the presintering temperature is 900-1100 ℃; further preferably, the pre-firing temperature is 1000 ℃.
Preferably, in the step (1), the presintering time is 0.5-1.5h; further preferably, the burn-in time is 1h; the water and impurities in the powder can be removed by presintering the raw material powder.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (1), the mass ratio of the pre-sintered mixed powder to the phosphoric acid is 1: (10-20); further preferably, the mass ratio of the pre-burned mixed powder to phosphoric acid is 1: (12-18); still more preferably, the mass ratio of the pre-sintered mixed powder to phosphoric acid after pre-sintering is 1: (13-16).
Preferably, in the step (1), the temperature of the mixed powder after presintering and the phosphoric acid are mixed for reaction is 200-300 ℃; further preferably, the temperature of the reaction is 220-280 ℃; still further preferably, the temperature of the reaction is 240-260 ℃; still more preferably, the temperature of the reaction is 250 ℃.
Preferably, in the step (1), the time for the mixed powder after presintering to react with phosphoric acid is 6-10h; further preferably, the reaction time is 7 to 9 hours; still more preferably, the reaction time is 7.5 to 8.5 hours; still more preferably, the reaction time is 8 hours.
Preferably, in the step (1), the pH of the supernatant fluid obtained in the last centrifugation step is more than or equal to 4; in the pH range, the prepared powder has better drying performance and cannot absorb moisture.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (1), the rotation speed of centrifugation is 7000-11000rpm; further preferably, the rotational speed of centrifugation is 8000-10000rpm; still more preferably, the rotational speed of the centrifugation is 8500-9500rpm; still more preferably, the rotational speed of the centrifugation is 9000rpm.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (1), the centrifuged solid is dried in an oven at 80 ℃ for 24 hours.
Preferably, in the step (1), the sintering temperature is 1100-1300 ℃, and the heating rate is 4-6 ℃ min -1 The method comprises the steps of carrying out a first treatment on the surface of the Further preferably, the sintering temperature is 1200 ℃, and the temperature rising rate is 5 ℃ min -1 。
Preferably, in the step (1), grinding is carried out after sintering, ball milling is adopted for grinding, and the grinding time is 10-14 hours; further preferably, the milling time is 11-13 hours; still more preferably, the milling time is 12 hours.
Preferably, in the step (1), grinding, drying in an oven at 80 ℃ for 24 hours, and sieving with a 60-mesh sieve.
Preferably, in the step (2), the binder comprises at least one of gelatin, polyvinyl alcohol and polyvinyl butyral; further preferably, the binder comprises one of gelatin and polyvinyl alcohol; still more preferably, the binder is gelatin.
Preferably, in the step (2), the foaming agent comprises at least one of sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium dodecyl benzene sulfonate and dodecanol; further preferably, the foaming agent comprises one of sodium dodecyl sulfate and ammonium dodecyl sulfate; still further preferably, the foaming agent is sodium dodecyl sulfate; the sodium dodecyl sulfate is selected as the foaming agent, and the prepared porous ceramic has the advantages of controllable porosity, uniform pore size distribution and the like.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (2), the mass ratio of water, a binder and pyrophosphate solid solution ceramic powder is 10: (0.4-1): (1-4); further preferably, the mass ratio of water, binder and pyrophosphate solid solution ceramic powder is 10: (0.5-0.9): (1.5-3.5); still further preferably, the mass ratio of water, binder and pyrophosphate solid solution ceramic powder is 10: (0.6-0.8): (2-3).
Preferably, in the step (2), water is added into the binder, and the mixture is stirred in a magnetic stirrer at 70-85 ℃ for 10-30min until the binder is completely dissolved, and then a foaming agent is added.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (2), after the pyrophosphate solid solution ceramic powder is added into the mixed solution, stirring is carried out, and the stirring speed is 1500rpm.
Preferably, in the step (3), the forming mode is freezing forming, and the temperature of the freezing forming is-20 to-16 ℃.
Preferably, in the step (3), demolding and drying are carried out after injection molding, and freeze drying is adopted for drying; further preferably, the degree of vacuum of freeze-drying is 1 to 10Pa; still more preferably, the degree of vacuum for freeze-drying is 4 to 6Pa.
Further preferably, in the step (3), freeze drying is adopted for drying, and the time of freeze drying is 10-14h; still more preferably, the lyophilization time is 11-13 hours; still more preferably, the lyophilization time is 12 hours.
Further preferably, in the step (3), freeze drying is adopted, and the temperature of the freeze drying is-42 to 38 ℃; still more preferably, the time of freeze drying is-40 ℃.
Preferably, in the preparation method of the pyrophosphate solid solution porous ceramic, in the step (3), the sintering temperature is 1300-1500 ℃.
Preferably, in the step (3), the sintering time is 0.5-1.5h; further preferably, the sintering time is 0.6-1.4 hours; still further preferably, the sintering time is 0.8 to 1.2 hours; still more preferably, the sintering time is 1h.
The second aspect of the invention provides a pyrophosphate solid solution porous ceramic, which is prepared by the preparation method of the pyrophosphate solid solution porous ceramic.
Preferably, the dielectric constant of the pyrophosphate solid solution porous ceramic is 1.7-2 (13.7-15.7 GHz).
Preferably, the pyrophosphate solid solution porous ceramic has a dielectric loss of 0.005-0.01 (13.7-15.7 GHz) at normal temperature.
Preferably, the thermal conductivity of the pyrophosphate solid solution porous ceramic is 0.005-0.015 W.m -1 ·K -1 。
Preferably, the porosity of the pyrophosphate solid solution porous ceramic is 45-65%.
Preferably, the pore size of the pyrophosphate solid solution porous ceramic is 20-200 μm.
The invention provides application of the pyrophosphate solid solution porous ceramic in a wave-transparent material.
Preferably, the pyrophosphate solid solution porous ceramic is applied to radome wave-transmitting materials.
The beneficial effects of the invention are as follows:
the invention is implemented by using ZrP 2 O 7 The Zr lattice point position in the phase is introduced with two high temperature resistant metal elements Ti and Hf, and the pyrophosphate solid solution porous ceramic prepared by the foaming method has lower dielectric constant and lower heat conductivity coefficient compared with the single-component pyrophosphate porous ceramic.
According to the preparation method of the pyrophosphate solid solution, a sintering aid is not required to be added, and the prepared porous ceramic is controllable in porosity and uniform in void size distribution.
Drawings
FIG. 1 is a (TiZrHf) P prepared in example 1 2 O 7 Solid solution ceramic powder and ZrP prepared in example 2 2 O 7 XRD pattern of ceramic powder.
FIG. 2 is a (TiZrHf) P prepared in example 1 2 O 7 SEM image of solid solution porous ceramic.
FIG. 3 is a graph showing the dielectric constant data of the ceramic powders of examples 1 to 3.
FIG. 4 is a graph showing dielectric loss data of the ceramic powders of examples 1 to 3.
FIG. 5 is a graph of porosity versus compressive strength for porous ceramics.
Detailed Description
The present invention will be described in further detail with reference to specific examples. The starting materials used in the examples were all commercially available from conventional sources unless otherwise specified.
Example 1
The preparation method of the porous ceramic material of the example is as follows:
(1) Preparation of powder
25g of ZrO 2 、42g HfO 2 、16g TiO 2 Respectively presintering at 1000deg.C for 1 hr to remove H in sample 2 O and impurities; weighing 20g of mixed powder and 200mL of 85% phosphoric acid by mass fraction, adding into a flask, and placing into an oil bath heating pot to react for 8 hours at 250 ℃; cooling the reacted solution at room temperature, adding distilled water to wash to dissolve the solid completely, transferring to a centrifuge tube, and centrifuging in a centrifuge at 9000r.min -1 Maintaining for 5min, measuring pH of the supernatant until pH reaches 4, centrifuging, separating the precipitate from the supernatant, drying the precipitate in oven at 80deg.C for 24 hr, and then drying in muffle furnace at 5 deg.C for min -1 Heating to 1200 ℃ at a speed, preserving heat, and sintering for 1h to obtain sintered pure phase powder; ball-milling the sintered pure-phase powder in a zirconia ball-milling tank for 12 hours; ball milling, drying in oven at 80deg.C for 24 hr, sieving with 60 mesh sieve to obtain (TiZrHf) P 2 O 7 Solid solution ceramic powder.
(2) Preparation of porous ceramics
3g of the above (TiZrHf) P was weighed out by an analytical balance 2 O 7 Solid solution ceramic powder, 10mL of water, 0.8g of gelatin and 0.5g of sodium dodecyl sulfate; wherein the water is used as a dispersion medium, and gelatin and sodium dodecyl sulfate are respectively used as a binder and a foaming agent; mixing water and gelatin in a reaction vessel, heating to 80deg.C with a magnetic stirrer, stirring for about 20min until gelatin is completely dissolved, adding sodium dodecyl sulfate, stirring to dissolve, and weighing (TiZrHf) P 2 O 7 Adding the solid solution ceramic powder into a beaker; raising the stirring speed to 1500 r.min -1 About, stirring vigorously for 2-3min to generate enough foam and uniformly disperse sample powder, so that no obvious large bubbles exist, and coating vaseline on the surface of a silica gel mold to facilitate demolding; pouring the slurry into a silica gel mold, and pre-freezing in a freezer (18 ℃ below zero) of a refrigerator for 2 hours; after the slurry is solidified into a block, demolding the pre-frozen ceramic block, and freeze-drying at the temperature of-40 ℃ for 12 hours under the vacuum degree of 5 Pa; placing the dried ceramic block into a muffle furnace, heating to 1300 ℃ in air atmosphere, preserving heat, sintering for 1h, and cooling along with the furnace to prepare (TiZrHf) P with the porosity of 50.2% 2 O 7 Solid solution porous ceramics.
(TiZrHf) P prepared in step (1) of the present example 2 O 7 As can be seen from FIG. 1, the XRD pattern of the solid solution ceramic powder is shown in FIG. 1, (TiZrHf) P 2 O 7 Solid solution ceramic powder and ZrP 2 O 7 Diffraction peaks of the ceramic powder can be in one-to-one correspondence, the peak type and the peak position are basically the same, but the diffraction peaks are obviously similar to ZrP 2 O 7 Diffraction peak-to-peak position (TiZrHf) P 2 O 7 These instructions (TiZrHf) P show that the diffraction peaks of (1) are shifted to a high angle 2 O 7 Solid solutions remain in the pure phase.
(TiZrHf) P prepared in step (2) of the present example 2 O 7 An SEM image of the solid solution porous ceramic is shown in fig. 2.
Example 2
The preparation method of the porous ceramic material of the example is as follows:
(1) Preparation of powder
50g of ZrO are taken 2 Presintering in muffle furnace at 1000deg.C for 1 hr to remove H in sample 2 O and impurities; 16g ZrO was taken 2 Weighing the powder and 200mL of 85% phosphoric acid by mass fraction, adding the mixture into a flask, and placing the flask into an oil bath heating pot to react for 8 hours at 250 ℃; cooling the reacted solution at room temperature, adding distilled water to wash to dissolve the solid completely, transferring to a centrifuge tube, and centrifuging in a centrifuge at 9000r.min -1 Maintaining for 5min, measuring pH of the supernatant until pH is greater than 4, centrifuging, separating precipitate from supernatant, drying at 80deg.C in oven for 24 hr, and drying in muffle furnace at 5deg.C for min -1 Heating to 1000 ℃ at a speed, preserving heat, and sintering for 1h to obtain sintered pure phase powder; ball milling the sintered pure phase powder for 12 hours again, drying and sieving to obtain ZrP 2 O 7 Ceramic powder.
(2) Preparation of porous ceramics
2g of the ZrP was weighed out by an analytical balance 2 O 7 Ceramic powder, 10mL of water, 0.6g of gelatin and 0.5g of sodium dodecyl sulfate, wherein the water acts as a dispersion medium, and the gelatin and the sodium dodecyl sulfate are respectively used as a binder and a foaming agent; mixing water and gelatin in a reaction vessel, heating to 70 ℃ by a magnetic stirrer, continuously stirring for about 20min until the gelatin is completely dissolved, adding sodium dodecyl sulfate, stirring and dissolving, and finally adding the weighed phosphate ceramic powder into a beaker; raising the stirring speed to 1500 r.min -1 About, stirring vigorously for 2-3min to generate enough foam and uniformly disperse sample powder, so that no obvious large bubbles exist, and coating vaseline on the surface of a silica gel mold to facilitate demolding; pouring the slurry into a silica gel mold, and pre-freezing in a freezer (18 ℃ below zero) of a refrigerator for 2 hours; after the slurry is solidified into a block, demolding the pre-frozen ceramic block, and freeze-drying at the temperature of-40 ℃ for 12 hours under the vacuum degree of 5 Pa; putting the dried ceramic block into a muffle furnace, heating to 1500 ℃ in air atmosphere, preserving heat, sintering for 1h, and cooling along with the furnace to prepare the ZrP with the porosity of 51.3 percent 2 O 7 Porous ceramics.
ZrP prepared in step (1) of the present example 2 O 7 The XRD pattern of the ceramic powder is shown in FIG. 1.
Example 3
(1) Preparation of powder
TiO is mixed with 2 Presintering at 1000deg.C for 1 hr to remove H in sample 2 O and impurities; weighing 20g of powder and 200mL of phosphoric acid with mass fraction of 85%, adding into a flask, and placing into an oil bath heating pot to react for 8 hours at 250 ℃; cooling the reacted solution at room temperature, adding distilled water to wash to dissolve the solid completely, transferring to a centrifuge tube, and centrifuging in a centrifuge at 9000r.min -1 Maintaining for 5min, measuring pH of the supernatant until pH is greater than 4, centrifuging, separating the precipitate from the supernatant, drying the precipitate in oven at 80deg.C for 24 hr, and then drying in muffle furnace at 5deg.C for min -1 Heating to 1200 ℃ at a speed, preserving heat, and sintering for 1h to obtain sintered pure phase powder; ball milling the sintered pure phase powder for 12 hours again, drying and sieving to obtain TiP 2 O 7 Ceramic powder.
(2) Preparation of porous ceramics
3g of the TiP was weighed out by an analytical balance 2 O 7 Ceramic powder, 10mL of water, 0.8g of gelatin and 0.5g of sodium dodecyl sulfate; wherein the water is used as a dispersion medium, and gelatin and sodium dodecyl sulfate are respectively used as a binder and a foaming agent; mixing water and gelatin in a reaction vessel, heating to 80 ℃ by a magnetic stirrer, continuously stirring for about 20min until the gelatin is completely dissolved, adding sodium dodecyl sulfate, stirring and dissolving, and finally adding the weighed phosphate ceramic powder into a beaker; raising the stirring speed to 1500 r.min -1 About, stirring vigorously for 2-3min to generate enough foam and uniformly disperse sample powder, so that no obvious large bubbles exist, and coating vaseline on the surface of a silica gel mold to facilitate demolding; pouring the slurry into a silica gel mold, and pre-freezing in a freezer (18 ℃ below zero) of a refrigerator for 2 hours; after the slurry is solidified into a block, demolding the pre-frozen ceramic block, and freeze-drying at the temperature of-40 ℃ for 12 hours under the vacuum degree of 5 Pa; freeze dryingPlacing the ceramic blank into a muffle furnace, heating to 1300 ℃ in air atmosphere, preserving heat, sintering for 1h, and cooling along with the furnace to prepare the TiP with 55% of porosity 2 O 7 Porous ceramics.
Example 4
The method for producing the porous ceramic material of this example is different from example 3 in that TiO is used in the production of the powder in step (1) of example 3 2 Replacement with HfO 2 And the gelatin material in step (2) was replaced with 1.3g, the remainder being the same as in example 3, hfP was obtained in this example 2 O 7 Porous ceramics.
For (TiZrHf) P prepared in step (1) of examples 1-3 2 O 7 Solid solution ceramic powder, zrP 2 O 7 Ceramic powder, tiP 2 O 7 The ceramic powder was subjected to dielectric property test, dielectric constant data are shown in fig. 3, and dielectric loss data are shown in fig. 4. As can be seen from fig. 3, tiP 2 O 7 The dielectric constant of the ceramic is the largest in the frequency range of 13.7-15.7GHz, and the value of the dielectric constant is about 6.2; next is ZrP 2 O 7 Ceramic, dielectric constant is about 4.7 in the same frequency range, and dielectric constant is the smallest (TiZrHf) P 2 O 7 The size of the solid solution ceramic is about 3.8 in the range of 13.7-15.7 GHz; three MP 2 O 7 The dielectric loss of the material is within the range of 0.005-0.01 in the frequency range of 13.7-15.7GHz, but is generally smaller than 0.01, and the material meets the basic requirement of the wave-transmitting material on the dielectric loss. (TiZrHf) P prepared in step (2) of example 1 2 O 7 The dielectric constant of the solid solution porous ceramic material is between 1.7 and 2, and the (TiZrHf) P of the invention 2 O 7 Solid solution porous ceramic materials have lower dielectric constants.
For (TiZrHf) P prepared in step (1) of examples 1-3 2 O 7 Solid solution ceramic powder, zrP 2 O 7 Ceramic powder, tiP 2 O 7 The ceramic powders were subjected to thermal conductivity test, and the results are shown in table 1 below.
TABLE 1 thermal conductivity of different dense ceramics
(TiZrHf) P prepared in step (2) of example 1 2 O 7 The thermal conductivity of the solid solution porous ceramic is 0.005-0.015 W.m -1 ·K -1 Between (TiZrHf) P of the present invention 2 O 7 Solid solution porous ceramics have lower thermal conductivities.
Preparation of (TiZrHf) P with reference to examples 1-4 2 O 7 Solid solution porous ceramics, zrP 2 O 7 Porous ceramic, tiP 2 O 7 Porous ceramic, hfP 2 O 7 The porous ceramic material with different porosities is obtained by adjusting the amount of the foaming agent, the relation between the porosities and the compressive strength of the different porous ceramic materials is shown in figure 5, and in figure 5, (TiZrHf) P 2 O 7 The porosities of the solid solution porous ceramics are respectively 0.7, 0.6, 0.55 and 0.5g corresponding to the foaming amounts, and the porosities of the three data points of other porous ceramics in the same group are respectively 0.7, 0.6 and 0.5g corresponding to the foaming amounts from large to small, as can be seen from the figure 5, (TiZrHf) P 2 O 7 Solid solution porous ceramics relative to ZrP 2 O 7 、TiP 2 O 7 、HfP 2 O 7 The porous ceramic has better compression strength when the porosity is less than 55 percent.
The above embodiments are preferred embodiments of the present invention, but the implementation of the present invention is not limited by the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, which is included in the protection scope of the present invention.
Claims (4)
1. The preparation method of the pyrophosphate solid solution porous ceramic is characterized by comprising the following steps of:
(1) ZrO (ZrO) 2 、HfO 2 、TiO 2 The powder is pre-burned and mixed at 900-1100 deg.c, and the mixed powder and phosphoric acid are mixed in 200-Mixing and reacting at 300 ℃, and then washing and centrifuging; with a temperature of 4-6deg.C min -1 Heating the solid obtained after centrifugation to 1100-1300 ℃ for sintering to obtain pyrophosphate solid solution ceramic powder;
(2) Mixing a binder, water and a foaming agent to obtain a mixed solution; adding the pyrophosphate solid solution ceramic powder into the mixed solution, and stirring, mixing and foaming at a stirring speed of 1500rpm to obtain slurry;
(3) Pouring the slurry obtained in the step (2) into a mold; freezing and molding at the temperature of minus 16 ℃ to minus 20 ℃, demolding, and freeze-drying at the temperature of minus 42 ℃ to minus 38 ℃ to obtain a molded embryo; sintering the formed blank to obtain pyrophosphate solid solution porous ceramic with the pore diameter of 20-200 mu m;
wherein in the step (1), the ZrO 2 、HfO 2 、TiO 2 The mass ratio of (1-2): (2-3) 1), wherein the mass ratio of the mixed powder to the phosphoric acid is 1: (10-20);
in the step (2), the binder comprises at least one of gelatin, polyvinyl alcohol and polyvinyl butyral, and the mass ratio of water to binder to pyrophosphate solid solution ceramic powder is 10: (0.4-1): (1-4) the foaming agent is at least one selected from sodium dodecyl sulfate, ammonium dodecyl sulfate and sodium dodecyl benzene sulfonate;
in the step (3), the sintering temperature is 1300-1500 ℃.
2. The method for producing a pyrophosphate solid solution porous ceramic according to claim 1, wherein in the step (1), the centrifugation step is required to satisfy the condition that the pH of the supernatant of the last centrifugation is not less than 4.
3. A pyrophosphate solid solution porous ceramic, characterized in that it is prepared by the method for preparing a pyrophosphate solid solution porous ceramic according to claim 1 or 2; the dielectric constant of the pyrophosphate solid solution porous ceramic is 1.7-2 under the condition of 13.7-15.7 GHz; the pore diameter of the pyrophosphate solid solution porous ceramic is 20-200 mu m.
4. Use of the pyrophosphate solid solution porous ceramic according to claim 3 in a wave-transparent material.
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| CN114751731A (en) * | 2022-04-11 | 2022-07-15 | 武汉科技大学 | Zirconium pyrophosphate complex phase porous ceramic material based on foaming method and preparation method thereof |
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| US5102836A (en) * | 1990-06-06 | 1992-04-07 | Center For Innovative Technology | Ceramic materials with low thermal conductivity and low coefficients of thermal expansion |
| WO2004011390A1 (en) * | 2002-07-26 | 2004-02-05 | Ngk Insulators, Ltd. | Method for producing porous ceramic article |
| CN113511890A (en) * | 2021-04-02 | 2021-10-19 | 武汉科技大学 | Zirconium pyrophosphate porous ceramic material based on foaming method and preparation method thereof |
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