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CN-122010551-A - Mg (magnesium)3TiO5Microwave dielectric material and preparation method thereof

CN122010551ACN 122010551 ACN122010551 ACN 122010551ACN-122010551-A

Abstract

The application discloses a Mg 3 TiO 5 microwave dielectric material and a preparation method thereof, which belong to the field of microwave dielectric materials, wherein the chemical formula of the microwave dielectric material is Mg 3 TiO 5 , the Q multiplied by f is 198000GHz, the fluctuation of microwave dielectric performance is less than or equal to 5 percent within the range of-50 ℃ to 200 ℃, the preparation method comprises the steps of (1) proportioning MgO or basic magnesium carbonate and TiO 2 with the purity of more than 99 percent and the grain size of 400-600nm according to the composition of product elements to obtain initial powder, (2) ball milling the initial powder obtained in the step (1), drying, sieving and presintering, and then performing secondary ball milling, drying and sieving, and (3) adding the powder obtained in the step (2) into polyvinyl alcohol solution for granulation according to the powder, then performing compression molding, and sintering the obtained green embryo in the air atmosphere at 1320-1440 ℃ to obtain the Mg 3 TiO 5 microwave dielectric material.

Inventors

  • ZHANG NAIYUE
  • ZHANG PENGCHENG
  • ZHANG SHENGYU
  • XIE SHICHEN
  • JIN XIAOPENG
  • CHEN ZHIQIN
  • Zeng Yunai
  • TONG BAOCHEN
  • ZHOU JIN

Assignees

  • 合隆防爆电气有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (8)

  1. 1. A Mg 3 TiO 5 microwave dielectric material is characterized in that the chemical formula is Mg 3 TiO 5 , the Q multiplied by f is at least 198000GHz, and the fluctuation of the microwave dielectric property is less than or equal to 5% within the range of-50 ℃ to 200 ℃.
  2. 2. The method for preparing the Mg 3 TiO 5 microwave dielectric material as claimed in claim 1, which is characterized by comprising the following steps: (1) MgO or basic magnesium carbonate and TiO 2 with the purity of more than 99% and the grain diameter of 400-600nm are proportioned according to the element composition of the product to obtain initial powder; (2) Ball milling is carried out on the initial powder obtained in the step (1), drying, sieving and presintering are carried out, and secondary ball milling, drying and sieving are carried out; (3) And (3) adding the polyvinyl alcohol solution into the powder obtained in the step (2) for granulating, then performing compression molding, and sintering the obtained green body in the air atmosphere at 1320-1440 ℃ to obtain the Mg 3 TiO 5 microwave dielectric material.
  3. 3. The method for preparing the Mg 3 TiO 5 microwave dielectric material according to claim 2, wherein the preparation raw material in the step (1) is pretreated by drying MgO or basic magnesium carbonate and TiO 2 in a drying box to remove water.
  4. 4. The method for preparing the Mg 3 TiO 5 microwave dielectric material according to claim 2, wherein the ball milling method in the step (2) is characterized in that the obtained initial powder is put into a nylon ball milling tank and mixed according to the proportion of the powder to deionized water to zirconia balls of 1:3-4:5-10.
  5. 5. The method for preparing Mg 3 TiO 5 microwave dielectric material according to claim 4, wherein zirconia balls with diameters of 2.5-3.5mm,4.5-5.5mm and 9.5-10.5mm are adopted, respectively, and the powder in the nylon ball milling tank is ball milled in a planetary ball mill for 12-24 hours.
  6. 6. The method for preparing the Mg 3 TiO 5 microwave dielectric material according to claim 2, wherein the sieving in the step 2 is that sieving is performed by adopting a screen after primary drying, sieving is performed by adopting a screen after secondary drying, and the number of the screens adopted after secondary drying is larger than that adopted after primary drying.
  7. 7. The method for preparing the Mg 3 TiO 5 microwave dielectric material according to claim 2, wherein the granulating method in the step 3 is characterized in that a polyvinyl alcohol solution is added, wherein the adding amount of the polyvinyl alcohol accounts for 3-5% of the total mass of the powder for granulating, uniformly stirring, and sieving.
  8. 8. The method for preparing the Mg 3 TiO 5 microwave dielectric material according to claim 2, wherein the sintering in the step 3 is characterized in that the sample is subjected to heat preservation for 1h-3h at a temperature rising rate of 1.5-5 ℃ per minute at 600-700 ℃ to remove polyvinyl alcohol, then is subjected to sintering for 3-6 h at a temperature rising rate of 1.5-5 ℃ per minute at 1320-1440 ℃ in the air atmosphere, then is subjected to heat preservation for 0.5-3 h at a temperature rising rate of 0.5-2 ℃ per minute to be reduced to below 1000 ℃, and finally is subjected to natural cooling to obtain the material.

Description

Mg 3TiO5 microwave dielectric material and preparation method thereof Technical Field The invention belongs to the field of electronic ceramics and manufacturing thereof, and particularly relates to a high-low temperature resistant and ultralow-loss microwave dielectric ceramic and a preparation method thereof. Background The microwave dielectric ceramic is used as an important functional basic material of microwave and radio frequency devices, and is widely applied to key fields such as dielectric resonators, filters, dielectric antennas, base station radio frequency elements, satellite communication and the like. With the rapid development of high-speed communication technologies such as 5G, millimeter wave radar, satellite Internet, internet of things and the like, a microwave device has put forward more stringent requirements on signal stability, structural miniaturization and wide-temperature-area adaptability under high-frequency conditions. Particularly in high-reliability scenes such as aerospace, polar scientific investigation, military electronics and the like, a microwave device capable of keeping ultra-low loss in a wide temperature range is particularly critical, and the performance of the microwave device is directly related to the safety and operation stability of equipment. However, existing microwave dielectric ceramic materials still face a number of challenges in application. First, to obtain a higher q×f value, many material systems often need to be controlled by means of ion substitution, oxide addition, or multiphase recombination. The method not only increases the complexity of the preparation process and is not beneficial to large-scale production, but also can introduce structural defects or phase instability, so that the temperature coefficient (τf) of the method is difficult to effectively regulate. Secondly, under the complex conditions of high-low temperature circulation, extreme thermal environment and the like of satellite communication equipment related to a vehicle-mounted radar, the existing material is difficult to meet the requirements of high Q multiplied by f and dielectric stability in a wide temperature range, so that the frequency drift of a microwave device is aggravated, the signal distortion is increased and the device performance degradation is obvious in practical application. The microwave dielectric material is taken as a core base of a microwave device, and the performance of the microwave dielectric material directly determines the working quality of the device, so that the development of the material with low dielectric constant, high quality factor and excellent temperature stability is a key problem to be broken through in the current field. Disclosure of Invention The invention provides a microwave dielectric material Mg 3TiO5 which has high Q multiplied by f, moderate dielectric constant, excellent temperature stability and high density. The material can be sintered to form a spinel structure pure phase at 1320-1440 ℃, and the space group is Fd-3m, so that the material has good crystal phase stability. The microwave dielectric properties of the composite material are excellent, epsilon r is 15.3, Q multiplied by f is 198000GHz, tau f is 45 ppm/DEGC, the sintering temperature is low (ST is 1350-1380 ℃), and the composite material has high preparation feasibility and economy. More prominently, the dielectric property of the material fluctuates by about 5 percent in a wide temperature range of 50 ℃ below zero to 200 ℃ below zero, which is obviously superior to the conventional microwave dielectric ceramic, shows excellent high-low temperature stability and can meet the strict requirements of high reliability and high frequency communication equipment on stable operation. Therefore, the Mg 3TiO5 microwave dielectric ceramic material developed by the invention can effectively solve the defects of the existing material in the aspects of temperature stability and dielectric loss, and provides a material scheme with obvious application advantages for a new generation of high-frequency and high-reliability microwave devices. The invention aims to provide an Mg 3TiO5 microwave dielectric material and a preparation method thereof. The chemical expression of the microwave dielectric ceramic is Mg 3TiO5, and the microwave dielectric ceramic is prepared by a solid phase method. Mg 3TiO5 ceramics prepared by sintering at 1320-1440 ℃ are all pure phases with spinel structures, and space group is Fd-3m. The optimal microwave dielectric property is epsilon r~15.3,Q×f ~198000 GHz,τf to-45 ppm/°c, and st=1350-1380 ℃. The Mg 3TiO5 microwave dielectric material with high and low temperature resistance and ultralow loss is prepared by the following steps: (1) MgO or basic magnesium carbonate (Mg (OH) 2・4MgCO3・5H2O）、TiO2) with the purity of more than 99% and the grain size of 400-600 nm is proportioned according to chemical formula to obtain initial powder. (2) And (3) placing