阅读说明：本技术 复合氧化锆材料及其制备方法 (Composite zirconia material and preparation method thereof ) 是由 宋锡滨 赵莎 王军 焦英训 于 2020-06-19 设计创作，主要内容包括：本发明提供了一种复合氧化锆材料及其制备方法。复合氧化锆材料为掺杂有Al、Y、Ca、Ba、Mg、Ce和Ti中一种或多种掺杂元素的氧化锆材料。通过掺杂上述元素并将各掺杂元素的含量控制在上述范围内,一方面能够改善氧化锆晶型结构,使其表现出更佳的介电性能,以满足毫米波频段应用要求；另一方面,这些元素的成本也相对较低,也有利于节约复合氧化锆材料的生产成本。与此同时,这些掺杂元素的掺杂效果相对更容易,也能够降低掺杂难度,形成的材料粒径更为均匀,性能更佳。(The invention provides a composite zirconia material and a preparation method thereof. The composite zirconia material is a zirconia material doped with one or more doping elements of Al, Y, Ca, Ba, Mg, Ce and Ti. By doping the elements and controlling the content of each doped element within the range, on one hand, the crystal structure of the zirconium oxide can be improved, so that the zirconium oxide has better dielectric property, and the application requirement of a millimeter wave frequency band is met; on the other hand, the cost of the elements is relatively low, and the production cost of the composite zirconia material is saved. Meanwhile, the doping effect of the doping elements is relatively easier, the doping difficulty can be reduced, the particle size of the formed material is more uniform, and the performance is better.)

1. The composite zirconia material is characterized by being a zirconia material doped with one or more doping elements of Al, Y, Ca, Ba, Mg, Ce and Ti.

2. The composite zirconia material according to claim 1, wherein the doping amount of the Al element is 0 to 20 wt%, the doping amount of the Y element is 0.02 to 6.5 wt%, the doping amount of the calcium element is 0 to 15 wt%, the doping amount of the Ba element is 0 to 5 wt%, the doping amount of the Mg element is 0 to 20 wt%, the doping amount of the Ce element is 0 to 18 wt%, and the doping amount of the Ti element is 0 to 1.5 wt% in terms of oxide;

preferably, the doping amount of the Al element is 0-18 wt%, the doping amount of the Y element is 1-5 wt%, the doping amount of the calcium element is 0-12 wt%, the doping amount of the Ba element is 0-3 wt%, the doping amount of the Mg element is 0-12 wt%, the doping amount of the Ce element is 0-12.5 wt%, and the doping amount of the Ti element is 0-1 wt% calculated by oxide.

3. The composite zirconia material according to claim 2,

the doping elements are the Y element and the Ba element, and the doping amount of the Y element is 1-5 wt% and the doping amount of the Ba element is 0.05-1.5 wt% calculated by oxide; alternatively, the first and second electrodes may be,

the doping elements are the Y element and the Ti element, and the doping amount of the Y element is 1.5-4 wt% and the doping amount of the Ti element is 0.02-1 wt% in terms of oxide; alternatively, the first and second electrodes may be,

the doping elements are the Y element, the Al element and the Ba element, and in terms of oxides, the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-12 wt%, and the doping amount of the Ba element is 0.05-1.2 wt%; alternatively, the first and second electrodes may be,

the doping elements are the Y element, the Al element and the Ti element, and in terms of oxides, the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-8 wt%, and the doping amount of the Ti element is 0.02-0.08 wt%; alternatively, the first and second electrodes may be,

the doping elements are the Y element, the Ce element and the Ba element, and in terms of oxides, the doping amount of the Y element is 1.5-3 wt%, the doping amount of the Ce element is 2-6 wt%, and the doping amount of the Ba element is 0.08-0.1 wt%; alternatively, the first and second electrodes may be,

the doping elements are the Y element, the Ce element and the Ti element, and in terms of oxides, the doping amount of the Y element is 1-3 wt%, the doping amount of the Ce element is 2-7 wt%, and the doping amount of the Ti element is 0.02-0.08 wt%.

4. The composite zirconia material according to any one of claims 1 to 3, characterized in thatCharacterized in that the granularity D50 of the composite zirconia material is 0.08-0.4 mu m, and the specific surface area is 7-18 m²/g。

5. A method for preparing the composite zirconia material according to any one of claims 1 to 4, characterized in that the method comprises the steps of:

mixing a zirconium salt and the salt of the doping element according to the elemental composition of the composite zirconia material to be prepared to form a solid mixed salt;

heating the solid mixed salt in a medium temperature furnace to 400-500 ℃ for low-temperature calcination to obtain a precursor;

dispersing the precursor in a planetary mill to obtain a dispersed precursor;

and calcining the dispersed precursor at a high temperature of 1000-1200 ℃ to obtain the composite zirconia material.

6. The preparation method according to claim 5, wherein the zirconium salt is one or more of zirconium oxychloride and zirconium nitrate; the doping elements are one or more of Al, Y, Ca, Ba, Mg, Ce and Ti, wherein the salt of the Al element is one or more of ammonium aluminum carbonate, ammonium aluminum sulfate, aluminum nitrate and aluminum chloride, the salt of the Y element is one or more of yttrium chloride and yttrium nitrate, the salt of the Ca element is one or more of calcium chloride, calcium nitrate and calcium sulfate, the salt of the Ba element is one or more of barium chloride, barium nitrate, barium sulfate and barium hydroxide, the salt of the Mg element is one or more of magnesium nitrate and magnesium chloride, the salt of the Ce element is one or more of cerium nitrate and cerium chloride, and the salt of the Ti element is one or more of titanium chloride and titanium sulfate.

7. The method according to claim 5 or 6, wherein the low-temperature calcination process comprises:

heating the solid mixed salt from room temperature to 165-180 ℃, and preserving heat for 2-3 hours to obtain preheated mixed salt;

and heating the preheated mixed salt to 400-500 ℃ within 1-1.5 h, and keeping the temperature for 2-3 h to perform low-temperature calcination to obtain the precursor.

8. The preparation method of claim 7, wherein in the planetary mill dispersing process, the rotating speed of the planetary mill is 250-300 r/s, and the dispersing time is 30-60 min.

9. The preparation method of claim 8, wherein the calcination time in the high-temperature calcination process is 4-5 hours.

10. A production method according to claim 5 or 6, characterized in that the zirconium salt and the salt of the doping element are mixed in a dry mixer to obtain the solid mixed salt; the high-temperature calcination process is carried out in a roller furnace.

Technical Field

The invention relates to the technical field of inorganic materials, in particular to a composite zirconia material and a preparation method thereof.

Background

With the development of the 5G technology, the signal bandwidth is larger, the transmission speed is high, a frequency spectrum above 3GHz is adopted, the millimeter wave wavelength is shorter, the penetration force is poor, the attenuation is large, and the coverage area is reduced. The evolution and demand of the growth promoting materials in the 5G era, and the emergence of new technologies put forward new performance requirements on the materials, including microwave dielectric ceramics, PCB materials, semiconductor materials, mobile phone antenna materials, heat conduction and radiation materials and the like, all change in the 5G application.

Dielectric properties are one of the important factors affecting the transmission speed and sensitivity of communication equipment. Since 5G will use higher frequencies, higher demands are made on losses in some ceramic material applications.

The fingerprint identification function in the smart phone requires that the fingerprint identification speed is high, and the appearance has tactile sensation and aesthetic feeling. The zirconia ceramics has the advantages of high strength, high hardness, acid and alkali corrosion resistance, high chemical stability and the like, has the characteristics of heat dispersion, no signal shielding, scratch resistance, wear resistance, good appearance effect and the like, and is applied to the shell of a mobile phone backboard, a fingerprint hand cover plate, a 5G base station and wearable equipment and small structural members for locking a screen, a volume key and the like.

At present, the preparation method of the composite zirconia is commonly used in a sol-gel method, a coprecipitation process, a hydrothermal process and the like, and for example, a method for preparing the composite zirconia by using a high-temperature high-pressure atomizing nozzle is disclosed in patent CN107285763B, but the method is high in cost and is not beneficial to industrial large-scale production. In addition, the composite zirconia material prepared in the prior art often has the problem that dielectric properties such as dielectric constant, dielectric loss and the like cannot meet the application requirements of millimeter wave frequency bands.

Disclosure of Invention

The invention mainly aims to provide a composite zirconia material and a preparation method thereof, and aims to solve the problem that dielectric properties such as dielectric constant, dielectric loss and the like of the composite zirconia material in the prior art cannot meet the application requirements of a millimeter wave frequency band.

In order to achieve the above object, according to one aspect of the present invention, there is provided a composite zirconia material, wherein the composite zirconia material is a zirconia material doped with one or more doping elements of Al, Y, Ca, Ba, Mg, Ce, and Ti.

Further, the doping amount of Al element is 0-20 wt%, the doping amount of Y element is 0.02-6.5 wt%, the doping amount of calcium element is 0-15 wt%, the doping amount of Ba element is 0-5 wt%, the doping amount of Mg element is 0-20 wt%, the doping amount of Ce element is 0-18 wt%, and the doping amount of Ti element is 0-1.5 wt%; preferably, the doping amount of the Al element is 0-18 wt%, the doping amount of the Y element is 1-5 wt%, the doping amount of the calcium element is 0-12 wt%, the doping amount of the Ba element is 0-3 wt%, the doping amount of the Mg element is 0-12 wt%, the doping amount of the Ce element is 0-12.5 wt%, and the doping amount of the Ti element is 0-1 wt% calculated by oxide.

Furthermore, the doping elements are Y element and Ba element, and the doping amount of the Y element is 1-5 wt% and the doping amount of the Ba element is 0.05-1.5 wt% calculated by oxide; or the doping elements are Y element and Ti element, and the doping amount of the Y element is 1.5-4 wt% and the doping amount of the Ti element is 0.02-1 wt% calculated by oxide; or the doping elements are Y element, Al element and Ba element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-12 wt% and the doping amount of the Ba element is 0.05-1.2 wt% in terms of oxide; or the doping elements are Y element, Al element and Ti element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-8 wt% and the doping amount of the Ti element is 0.02-0.08 wt% in terms of oxide; or the doping elements are Y element, Ce element and Ba element, and the doping amount of the Y element is 1.5-3 wt%, the doping amount of the Ce element is 2-6 wt% and the doping amount of the Ba element is 0.08-0.1 wt% calculated by oxide; or the doping elements are Y element, Ce element and Ti element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Ce element is 2-7 wt% and the doping amount of the Ti element is 0.02-0.08 wt% in terms of oxide.

Furthermore, the granularity D50 of the composite zirconia material is 0.08-0.4 mu m, and the specific surface area is 7-18 m²/g。

According to another aspect of the present invention, there is also provided a preparation method of the above composite zirconia material, which comprises the following steps: mixing a zirconium salt and a salt of a doping element according to the elemental composition of the composite zirconia material to be prepared to form a solid mixed salt; heating the solid mixed salt in a medium temperature furnace to 400-500 ℃ for low temperature calcination to obtain a precursor; dispersing the precursor in a planetary mill to obtain a dispersed precursor; and (3) calcining the dispersed precursor at a high temperature of 1000-1200 ℃ to obtain the composite zirconia material.

Further, the zirconium salt is one or more of zirconium oxychloride and zirconium nitrate; the doping elements are one or more of Al, Y, Ca, Ba, Mg, Ce and Ti, wherein the salt of the Al element is one or more of ammonium aluminum carbonate, ammonium aluminum sulfate, aluminum nitrate and aluminum chloride, the salt of the Y element is one or more of yttrium chloride and yttrium nitrate, the salt of the Ca element is one or more of calcium chloride, calcium nitrate and calcium sulfate, the salt of the Ba element is one or more of barium chloride, barium nitrate, barium sulfate and barium hydroxide, the salt of the Mg element is one or more of magnesium nitrate and magnesium chloride, the salt of the Ce element is one or more of cerium nitrate and cerium chloride, and the salt of the Ti element is one or more of titanium chloride and titanium sulfate.

Further, the low-temperature calcination process comprises: heating the solid mixed salt from room temperature to 165-180 ℃, and preserving heat for 2-3 hours to obtain preheated mixed salt; and heating the preheated mixed salt to 400-500 ℃ within 1-1.5 h, and keeping the temperature for 2-3 h to perform low-temperature calcination to obtain a precursor.

Further, in the dispersing process of the planetary mill, the rotating speed of the planetary mill is 250-300 r/s, and the dispersing time is 30-60 min.

Furthermore, the calcination time in the high-temperature calcination process is 4-5 h.

Further, mixing a zirconium salt and a salt of a doping element in a dry mixer to obtain a solid mixed salt; the high temperature calcination process is carried out in a roller bed furnace.

The invention provides a composite zirconia material, which is a zirconia material doped with one or more doping elements of Al, Y, Ca, Ba, Mg, Ce and Ti. By doping the elements and controlling the content of each doped element within the range, on one hand, the crystal structure of the zirconium oxide can be improved, so that the zirconium oxide has better dielectric property, and the application requirement of a millimeter wave frequency band is met; on the other hand, the cost of the elements is relatively low, and the production cost of the composite zirconia material is saved. Meanwhile, the doping effect of the doping elements is relatively easier, the doping difficulty can be reduced, the particle size of the formed material is more uniform, and the performance is better.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As described in the background art, the dielectric properties of the composite zirconia material in the prior art, such as dielectric constant, dielectric loss, etc., do not meet the requirements of millimeter wave frequency band applications.

In order to solve the above problems, the present invention provides a composite zirconia material, which is a zirconia material doped with one or more doping elements of Al, Y, Ca, Ba, Mg, Ce, and Ti. By doping the elements and controlling the content of each doped element within the range, on one hand, the crystal structure of the zirconium oxide can be improved, so that the zirconium oxide has better dielectric property, the dielectric constant of 20-70 Hz can reach 29.4-45, the dielectric loss can reach 0.0004-0.0078, the application requirement of a millimeter wave frequency band can be met, and the zirconium oxide crystal structure is suitable for the fields of mobile phone backboards, fingerprint hand cover plates, 5G base stations, shells of wearable equipment, small-sized structural members for screen locking, volume keys and the like. On the other hand, the cost of the elements is relatively low, and the production cost of the composite zirconia material is saved. Meanwhile, the doping effect of the doping elements is relatively easier, the doping difficulty can be reduced, the particle size of the formed material is more uniform, and the performance is better.

In a preferred embodiment, the doping amount of Al element is 0-20 wt%, the doping amount of Y element is 0.02-6.5 wt%, the doping amount of calcium element is 0-15 wt%, the doping amount of Ba element is 0-5 wt%, the doping amount of Mg element is 0-20 wt%, the doping amount of Ce element is 0-18 wt%, and the doping amount of Ti element is 0-1.5 wt% calculated by oxide; preferably, the doping amount of the Al element is 0-18 wt%, the doping amount of the Y element is 1-5 wt%, the doping amount of the calcium element is 0-12 wt%, the doping amount of the Ba element is 0-3 wt%, the doping amount of the Mg element is 0-12 wt%, the doping amount of the Ce element is 0-12.5 wt%, and the doping amount of the Ti element is 0-1 wt% calculated by oxide. The doping amount of each doping element is controlled within the range, so that the dielectric property of the composite zirconia material is further improved.

For the purposes of further improving the particle morphology, optimizing the crystal phase structure and improving the dielectric property, in a preferred embodiment, the doping elements are Y element and Ba element, and the doping amount of the Y element is 1-5 wt% and the doping amount of the Ba element is 0.05-1.5 wt% calculated by oxide; or the doping elements are Y element and Ti element, and the doping amount of the Y element is 1.5-4 wt% and the doping amount of the Ti element is 0.02-1 wt% calculated by oxide; or the doping elements are Y element, Al element and Ba element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-12 wt% and the doping amount of the Ba element is 0.05-1.2 wt% in terms of oxide; or the doping elements are Y element, Al element and Ti element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Al element is 5-8 wt% and the doping amount of the Ti element is 0.02-0.08 wt% in terms of oxide; or the doping elements are Y element, Ce element and Ba element, and the doping amount of the Y element is 1.5-3 wt%, the doping amount of the Ce element is 2-6 wt% and the doping amount of the Ba element is 0.08-0.1 wt% calculated by oxide; or the doping elements are Y element, Ce element and Ti element, and the doping amount of the Y element is 1-3 wt%, the doping amount of the Ce element is 2-7 wt% and the doping amount of the Ti element is 0.02-0.08 wt% in terms of oxide.

Preferably, the particle size D50 of the composite zirconia material is 0.08-0.4 μm, and the specific surface area is 7-18 m²(ii) in terms of/g. The material performance is more excellent under the particle size and the specific surface area.

According to another aspect of the present invention, there is also provided a preparation method of the above composite zirconia material, the preparation method comprising the steps of: mixing a zirconium salt and a salt of a doping element according to the elemental composition of the composite zirconia material to be prepared to form a solid mixed salt; heating the solid mixed salt in a medium-temperature furnace to 400-500 ℃ for low-temperature calcination to obtain a precursor; dispersing the precursor in a planetary mill to obtain a dispersed precursor; and (3) calcining the dispersed precursor at a high temperature of 1000-1200 ℃ to obtain the composite zirconia material.

According to the method provided by the invention, a specific doping element is selected to dope the zirconium oxide. Through solid powder mixing, low-temperature calcination and later-stage sanding dispersion, the uniformity of a finished product can be improved, and then high-temperature calcination is carried out to obtain a final finished product with uniform granularity. And the doping elements can be fully mixed by adding sand grinding before calcination, so that the doping uniformity is improved. Meanwhile, the process is simple, the parameters are easy to control, and the stability is good. The composite zirconia material prepared by the method has more outstanding dielectric property, the dielectric constant of 20-70 Hz can reach 29.4-45, the dielectric loss can reach 0.0004-0.0078, the application requirement of a millimeter wave frequency band can be met, and the composite zirconia material is suitable for the fields of mobile phone backboards, fingerprint hand cover plates, 5G base stations, shells of wearable equipment, small structural members for screen locking, volume keys and the like. On the other hand, the cost of the elements is relatively low, and the production cost of the composite zirconia material is saved.

The zirconium salt and the salt of the doping element may be any salts as long as they can form the corresponding oxides by calcination, and in a preferred embodiment, the zirconium salt is one or more of zirconium oxychloride and zirconium nitrate in terms of stability of the doping process, preparation cost and the like; the doping elements are one or more of Al, Y, Ca, Ba, Mg, Ce and Ti, wherein the salt of the Al element is one or more of ammonium aluminum carbonate, ammonium aluminum sulfate, aluminum nitrate and aluminum chloride, the salt of the Y element is one or more of yttrium chloride and yttrium nitrate, the salt of the Ca element is one or more of calcium chloride, calcium nitrate and calcium sulfate, the salt of the Ba element is one or more of barium chloride, barium nitrate, barium sulfate and barium hydroxide, the salt of the Mg element is one or more of magnesium nitrate and magnesium chloride, the salt of the Ce element is one or more of cerium nitrate and cerium chloride, and the salt of the Ti element is one or more of titanium chloride and titanium sulfate.

In the actual mixing process, preferably, the zirconium salt and the yttrium salt are mixed to form a mixture A; the salts of the other elements and mixture a are then mixed in a dry mixer to give the final solid mixture, which is more homogeneous.

In a preferred embodiment, the low temperature calcination process comprises: heating the solid mixed salt from room temperature to 170 ℃, and preserving heat for 2 hours to obtain preheated mixed salt; and (3) heating the preheated mixed salt to 400 ℃ within 1.5h, and keeping the temperature for 2h to perform low-temperature calcination to obtain a precursor. The temperature is raised from room temperature to 170 ℃ to obtain a mixed solution (soluble salts can be dissolved to form a solution because the selected raw materials are all provided with crystal water and the crystal water is released to water after being heated to a certain temperature), and then the temperature is raised to 400 ℃ to quickly dehydrate the solution and obtain the oxide with uniform doping.

In order to further improve the particle uniformity and the properties of the final product, in a preferred embodiment, the rotation speed of the planetary mill is 300r/s and the dispersion time is 30min during the dispersion process of the planetary mill. More preferably, the calcination time in the high-temperature calcination process is 4 h. Under the process condition, the high-temperature calcination process is more sufficient, the doping effect of the doping elements is better, and further the dielectric property of the composite zirconia material is favorably improved.

In the above high-temperature calcination process, the dispersed particles may be calcined in a high-temperature furnace with exhaust gas, and in order to improve calcination stability and mixing uniformity, in a preferred embodiment, a zirconium salt and a salt of a doping element are mixed in a dry mixer to obtain a solid mixed salt; the high temperature calcination process is carried out in a roller bed furnace.

The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.