A kind of close niobate energy storage glass ceramics of the glass structure of boracic and its preparation
Method
Technical field
The present invention relates to glass ceramic material field and preparation method thereof, in particular to a kind of glass structure of boracic is close
Niobate energy storage glass ceramic material and preparation method thereof.
Background technique
In recent years, the development of pulse technique and higher application demand propose the electrical breakdown withstand and energy-storage property of material
More harsh requirement, therefore the ferroelectric glass-ceramic material as the big branch of energy storage dielectric material one is increasingly by scientific research
The favor of worker.Ferroelectric glass-ceramic depends on the high breakdown field strength of its inner glass phase and good Jie of ferroelectric crystalline phases
The mutually coordinated matching of both electrical properties finally makes material have biggish energy storage density.
According to linear dielectric energy storage density calculation formula, can obtain the energy storage density of energy-storage travelling wave tube with
The relative dielectric constant of its own is related with disruptive field intensity, and wherein breakdown strength influences the size of energy storage density bigger.In order to
Make glass ceramic material energy storage density with higher, the glass phase composition for influencing glass ceramic material breakdown strength should be weighed
Point research.Glass structure mainly generates body, Network modifier and network intermediate composition by network.Breakdown strength and glass structure
Tightness degree have an important relationship, the electrical breakdown of glass ceramics mainly causes the long-range of a large amount of carriers to be transported with when applying external electric field
It moves related.And if remaining glass phase has a close glass structure, carrier long range motion if, can become difficult, to mention
High breakdown strength.Silica is that most important network generates body, and stable structure is used by a large amount of glass ceramics systems.Silicon oxygen
Key (106 kcal/mol) is smaller compared to boron oxygen key (119 kcal/mol) bond energy, it is contemplated that obtain glass more closely
Network structure, it is a kind of method that the bigger boron oxide of bond energy, which is added,.
Summary of the invention
It is an object of the invention to overcome defect existing in the prior art, it is close to provide a kind of plus boron glass structure
Niobate energy storage glass ceramic material and preparation method thereof, the reaction of this method raw material high uniformity, utilization rate is high, and obtained
Glass ceramic material has high disruptive field intensity, high dielectric constant.
To achieve the above object, glass ceramics of the present invention the technical solution adopted is that:
Crystal phase is the K for being 7:1:8 by molar ratio2CO3、Na2CO3And Nb2O5;Glass phase is to be by molar ratiox: (1-x) SiO2、
H2BO3;Crystal phase and glass phase molar ratio are that 4:1 is formulated through made from mixed melting, molding, annealing and Crystallizing treatment.
The preparation method of glass ceramic material of the present invention the technical solution adopted is that, include the following steps:
1) K for being 7:1:8 according to 4 molar ratios2CO3、Na2CO3And Nb2O5;Glass phase is the SiO for being 1:3 by molar ratio2、H2BO3;
Crystal phase is 4:1 with glass phase molar ratio and mixes;
2) silica crucible heating is added in the mixture in step 1) until forming uniformly mixed melt;Melt is poured into mold
Molding, obtains glass sample, then make annealing treatment to glass sample;
3) will by annealing glass sample carry out Crystallizing treatment, Crystallizing treatment be 950 DEG C heat preservation, heat preservation total time be
2h obtains K2O-Na2O-Nb2O5-SiO2-B2O3System glass ceramic material.
Further, the heating temperature in step 2 is 1450~1500 DEG C.
Further, the annealing in step 2 is in 500~600 DEG C of 8~11h of heat preservation.
Further, the glass sample crystallization temperature in step 3) is 950 DEG C or so.
Further, the crystallization temperature in step 3) is that glass matrix sample is determining through DSC differential thermal analysis test.
Compared with prior art, the beneficial effects of the present invention are:
The potassium-sodium niobate glass ceramic material porosity produced by the present invention is minimum, needs network to be formed simultaneously as forming glass
Body, network outer body and network intermediate three parts.B2O3Body is generated when for octahedral structure with more as glass network
Close structure.Therefore the present invention rationally controls B2O3The ratio of content generates more close network structure, and dielectric constant can
Up to 180, disruptive field intensity can be down to 0.073, increase energy storage density up to 460kV/cm, dielectric loss, up to 1.64J/cm3。
In addition, due to being during the preparation process multiform into NaNbO3Mutually there is embodiment more to joined Na2CO3, therefore these embodiments
Also more crystal phase can be obtained.
Preparation method of the present invention only needs to carry out mixed melting, molding, annealing and Crystallizing treatment to each raw material, can be obtained
Potassium-sodium niobate glass ceramic material, the present invention use fusion method, and the reaction of raw material high uniformity, experimental implementation is simple, and molding side
Fado can effectively eliminate internal stress after annealing, while allow crystal phase to grow more using segmentation heat preservation when Crystallizing treatment
Completely, crystallization is more thorough, and internal grain is thinner, homogenization degree is higher and the higher glass pottery of energy storage density conducive to obtaining
Porcelain.
Detailed description of the invention
Fig. 1 is niobium prepared by the embodiment of the present invention 1, embodiment 2, embodiment 3, embodiment 4, embodiment 5 and embodiment 6
X-ray diffraction (XRD) map of sour potassium sodium base glass ceramic material;
Fig. 2 is the dielectric constant and dielectric loss figure of potassium-sodium niobate-based glass ceramic material prepared by the present invention.
Specific embodiment
The specific steps of the present invention are as follows:
1) K for being 7:1:8 according to molar ratio2CO3、Na2CO3And Nb2O5;Glass phase is to be by molar ratiox: (1-x) SiO2、
H2BO3;Crystal phase is 4:1 with glass phase molar ratio and mixes, and obtains mixture;
2) when silica crucible being heated to 1000 ~ 1200 DEG C from room temperature with furnace, it is initially added into mixture, then proceedes to be heated to
1450~1500 DEG C, and 50~60min is kept the temperature, make that mixture sufficiently melts and bubble-free finally obtains mixed melting material;Room temperature
It is lower to form mixed melting material on copper sheet mold, then annealing 8~11h in 500~600 DEG C at is put into furnace rapidly, to eliminate
Internal stress obtains glass sample;
Above-mentioned glass sample is kept the temperature at 950 DEG C, carries out segmentation Crystallizing treatment, the total time of Crystallizing treatment is 4h, then with furnace
It is cooled to room temperature, obtains K2O-Na2O-Nb2O5-SiO2-B2O3System glass ceramic material.
The present invention is described in further details below in conjunction with specific embodiment:
Embodiment 1:
The Crystallizing treatment of glass sample in the present embodiment: in 950 DEG C of heat preservation 4h.
The preparation method of the present embodiment glass ceramic material includes the following steps:
1) the present embodiment molar ratio is the K of 7:1:82CO3、Na2CO3And Nb2O5;Glass phase is the SiO for being 1:0 by molar ratio2、
H2BO3;Crystal phase is that 4:1 is mixed with glass phase molar ratio.
2) by silica crucible with stove heating from room temperature to 1100 DEG C when, be initially added into mixture, then proceed to be heated to
1500 DEG C, and keeping the temperature 60min at 1500 DEG C keeps mixture melting uniform, obtains mixed melting material;By mixed melting material in copper
It is formed on plate, then is put into furnace at 500 DEG C the 11h that anneals, the glass matrix after being annealed rapidly;
3) in 950 DEG C of heat preservation 4h, then furnace cooling obtains K to room temperature2O-Na2O-Nb2O5-SiO2-B2O3System glass ceramics
Material.
The potassium-sodium niobate glass ceramics that the present embodiment obtains is switched to the thin slice with a thickness of 0.1~0.2mm with cutting machine, it is thin
After piece is polished, cleaned, silver electrode paste is uniformly coated in thin slice tow sides, 20 minutes is kept the temperature in 600 DEG C, obtains glass to be measured
Glass ceramics sample.
Embodiment 2:
The glass phase of glass sample is the SiO for being 0.85:0.15 by molar ratio in the present embodiment2、H2BO3, and add at 1500 DEG C
Material melting and heat preservation 60min, other conditions are the same as embodiment 1.
Embodiment 3:
The formula of glass sample is the SiO of 0.7:0.3 in the present embodiment2、H2BO3, other conditions are the same as embodiment 1.
Embodiment 4:
The SiO that the formula of glass sample is 0.54: 0.46 in the present embodiment2、H2BO3, other conditions are the same as embodiment 1.
Embodiment 5:
The formula of glass sample is the SiO of 0.37:0.63 in the present embodiment2、H2BO3, other conditions are the same as embodiment 1.
Embodiment 6:
The formula of glass sample is the SiO of 0:1 in the present embodiment2、H2BO3, other conditions are the same as embodiment 1.
Fig. 1 be to the X-ray diffraction analysis of above six embodiments, illustrate different experiments formula to its crystallization degree with
The influence of object phase.It can be seen that 950oUnder the crystallization temperature of C, 6 kinds of embodiments have high crystallization degree, and crystal phase is mainly
NaNbO3。
It is potassium-sodium niobate glass ceramic material Jie that Fig. 2, which is to the table one of glass ceramic material made from above six embodiments,
Electric performance test is as a result, specific as follows:
The performance test data of the glass ceramics sample of one embodiment 1 to embodiment 4 of table preparation
Embodiment |
1 |
2 |
3 |
4 |
5 |
6 |
Dielectric constant |
150 |
75 |
100 |
73 |
70 |
72 |
Disruptive field intensity (kV/cm) |
425 |
460 |
400 |
415 |
375 |
350 |
Dielectric loss |
0.060 |
0.074 |
0.045 |
0.027 |
0.025 |
0.028 |
Energy storage density (J/cm3) |
1.34 |
1.43 |
1.18 |
1.05 |
0.89 |
0.73 |
According to energy storage formula:, disruptive field intensity is to influence one of energy storage density factor the most significant, glass pottery
Ceramic material is because glass is there are dielectric constant reduction, and disruptive field intensity increases, and therefore, the present invention is by rationally controlling antiferroelectric niobic acid
The content of sodium crystal generates the ferroelectric glass-ceramic of high dielectric constant high breakdown field strength and low-dielectric loss.Also, using melting
Method prepares sample, and simple process, forming method is more, and it is the important method for preparing high energy storage density material that resistance to breakdown strength is high.
The high dielectric constant of invention preparation and the potassium-sodium niobate glass ceramics of high breakdown field strength are expected to substitute traditional ferroelectric ceramic material
As energy storage material excellent one of important candidate material simultaneous technically and economically.
The present invention prepares potassium-sodium niobate glass ceramic material using fusion method, the advantage is that preparation method simplicity, technique
Process is simple, and molding can be controlled arbitrarily as needed, with short production cycle, is particularly suitable for industrialized production.In the present invention at crystallization
Reason is to make crystal phase growth more complete using 4h soaking time, and crystallization is more thorough, and can also be obtained by later period test
It arrives, when the potassium-sodium niobate-based glass ceramics sample interior crystal content in higher crystallization peak isothermal holding, obtained is higher, energy storage is close
Du Genggao.Potassium-sodium niobate-based glass ceramic material prepared by the present invention is a kind of with high dielectric constant high breakdown field strength and low
The ferroelectric glass-ceramic of dielectric loss.
It the foregoing is merely one embodiment of the present invention, is not all of or unique embodiment, art technology
Any equivalent transformation that personnel take technical solution of the present invention by reading description of the invention, is power of the invention
Benefit requires to be covered.