CN111620565A

CN111620565A - High-expansion-coefficient sealing glass ceramic and low-melting-point processing method

Info

Publication number: CN111620565A
Application number: CN202010563170.6A
Authority: CN
Inventors: 赵祥; 齐圣卫
Original assignee: Zibo Baoquan Light Industrial Products Co ltd
Current assignee: Zibo Baoquan Light Industrial Products Co ltd
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2020-09-04

Abstract

The invention discloses a high-expansion-coefficient sealing glass-ceramic and a low-melting-point processing method, which are characterized in that the high-expansion-coefficient sealing glass-ceramic comprises the following raw materials in parts by weight: SiO 2₂35 to 45 portions of ZnO, 2.5 to 12 portions of Bi₂O₃5.0 to 15.0 portions of Al₂O₃5.5-7.5 parts of B₂O₃7.0 to 15.0 portions of Na₂CO₃2.0-3.5 parts of C_U0.5-5.5 parts of O and TiO₂0.5-2.5 parts of P₂O₅1.0 to 3.0 portions of graphene, and the crystallization in the crystallization process of the low melting point processing method is 450-480 ℃, the invention has the advantages that a proper amount of B203, Zn0 and Bi2O3 are used for replacing partial components in the microcrystalline glass, so that the melting temperature and the crystallization temperature of the microcrystalline glass are greatly reduced, and the graphene is creatively added in the crystallization process, so that amorphous molecular boron oxide can be converted into crystalline boron oxideIn addition, the structure has positive effect on the expansion coefficient.

Description

High-expansion-coefficient sealing glass ceramic and low-melting-point processing method

The technical field is as follows:

the invention belongs to the technical field of glass processing, and particularly relates to sealing glass ceramics with high expansion coefficient and a low-melting-point processing method.

Background art:

the traditional commercial sealing glass contains lead, and PbO-SiO and PbO-B are often selected₂0₃，PbO-B₂0-SiO₂And ZnO-PbO-SiO₂(ii) a The content of PbO is high, the pollution of lead to the environment causes attention in various aspects, and related policies or related measures are taken in many countries to limit or prohibit the use of lead-containing glass sealing materials for household electrical products, so that the microcrystalline glass for sealingLead-free treatment of (2) is indispensable.

According to the diagonal line and the adjacent principle of the periodic table of elements, elements which can replace lead are indium, tin, bismuth, indium, simple substances of ingots and oxides thereof are toxic; SnO-containing glass has poor insulating property, bismuth and other metal elements exist in the form of oxides in glass although bismuth is toxic, BiO is non-toxic, the electronic structures and atomic weights of bismuth and lead are extremely similar, and the bismuth and lead have many similar properties; therefore, in recent years, the preparation of lead-free sealing glass using bismuth instead of lead has been gaining more and more attention.

Bismuth-containing glasses currently under investigation are mainly Bi₂0₃-B₂0₃-SiO₂And Bi₂0₃-B₂0₃The glass system has a relatively low glass expansion coefficient, so that the glass crystal structure is relatively hard and fragile, is not beneficial to sealing, and cannot be suitable for sealing metal shells of electronic components or titanium alloy or aluminum alloy.

The search for a sealing microcrystalline glass which has better insulating property and is suitable for sealing the metal shell of an electronic component or the sealing of a titanium alloy or the sealing of an aluminum alloy is a hotspot of current research.

The invention content is as follows:

in order to solve the problems and overcome the defects of the prior art, the invention provides the sealing glass ceramics with high expansion coefficient and the processing method with low melting point, which can effectively solve the problem that the performances of the expansion coefficient and the insulativity are difficult to be coordinated.

The specific technical scheme for solving the technical problems comprises the following steps: the sealing microcrystalline glass with high expansion coefficient is characterized by comprising the following raw materials in parts by weight: SiO 2₂35 to 45 portions of ZnO, 2.5 to 12 portions of Bi₂O₃5.0 to 15.0 portions of Al₂O₃5.5-7.5 parts of B₂O₃7.0 to 15.0 portions of Na₂CO₃2.0-3.5 parts of C_U0.5-5.5 parts of O and TiO₂0.5-2.5 parts of P₂O₅1.0 to 3.0 portions.

Further, the raw material also comprises graphene.

Further, B in the raw materials₂O₃The mass ratio of the graphene to the graphene is 1: 0.2-0.9.

The low-melting-point processing method of the sealing glass-ceramic with high expansion coefficient is used for preparing the sealing glass-ceramic with high expansion coefficient, and is characterized by comprising the following steps:

(1) a smelting process: mixing the raw material components except the graphene, adding the raw material components into a glass melting furnace, melting at 1150-1220 ℃ for 2-3 hours, and then cooling to 1020-1100 ℃ for clarification for 1.6-2 hours to prepare glass liquid;

(2) a cold quenching process: directly adding the glass liquid with the clarified surface into water, performing cold quenching to obtain a glass body, adding the glass body into a ball mill, performing ball milling to obtain glass powder with the fineness of 0.05-0.07mm, and drying;

(3) a crystallization process: putting the green body into a high-temperature box-type resistance furnace, and heating to 300-340 ℃ at the rate of 7-8 ℃/min at room temperature; heating to 750 plus 820 ℃ at the speed of 3-5 ℃/min, adding graphene, cooling to 450 plus 480 ℃ at the speed of 1-3 ℃/min, and carrying out heat preservation and crystal growth for 3-3.5 h;

(5) and (3) annealing: cooling the crystallized glass at the speed of 5-7 ℃/min, naturally cooling and rolling when the temperature is reduced to 250-300 ℃, and then grinding into glass powder;

(6) and (5) adding a binder into the glass powder obtained in the step (5) for granulation, and then preparing a glass blank.

Further, the binder is PVA or PEG, and the using amount of the binder is 1-3% by mass of the glass powder obtained in the step (5).

Furthermore, the sealing glass ceramics are used for sealing metal shells of electronic components or titanium alloy or aluminum alloy;

the invention has the beneficial effects that:

SiO-ZnO-Bi of the invention₂O₃-Al₂O₃-B₂O₃System glass with appropriate amount of B₂0₃Zn0 and Bi₂O₃Replaces part of components in the microcrystalline glass, so that the melting temperature and the crystallization temperature of the microcrystalline glass are greatly reduced, and a crystal is obtainedThe processing method of the sealing microcrystalline glass with lower melting temperature reduces energy consumption and is beneficial to industrial application;

SiO-ZnO-Bi₂O₃-Al₂O₃-B₂O₃the system glass changes the components and the dosage of common glass ceramics, has higher expansion coefficient, obtains the glass ceramics with excellent sealing performance, and has good thermal expansion matching after sealing;

the original insulating property of a glass system can be kept by creatively adding the graphene in the crystallization process, and the fact that the graphene can convert amorphous molecular boron oxide into crystalline boron oxide under the condition of low-temperature crystallization is surprisingly found, the structure has a positive effect on the expansion coefficient, and the technical problem that the crystalline boron oxide is obtained by slowly cooling glassy boron oxide is solved,

the method for improving the expansion coefficient of the glass system by adding the graphene is realized, so that the glass system has a higher expansion coefficient, and the glass system with better insulating property and higher expansion coefficient is finally obtained.

Description of the drawings:

FIG. 1 is an electron microscope scanning image of molecular boron oxide in the prior art:

fig. 2 is a scanning electron microscope image of graphene in the prior art:

FIG. 3 is an electron microscope scanning image of crystalline boron oxide in graphene according to the present invention:

the specific implementation mode is as follows:

in the description of the invention, specific details are given only to enable a full understanding of the embodiments of the invention, but it should be understood by those skilled in the art that the invention is not limited to these details for the implementation. In other instances, well-known structures and functions have not been described or shown in detail to avoid obscuring the points of the embodiments of the invention. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The specific implementation mode of the invention is as follows:

the first embodiment is as follows:

the low-melting-point processing method of the high-expansion-coefficient sealing glass ceramics is characterized by comprising the following steps of:

(1) a smelting process: the sealing glass ceramics with high expansion coefficient is characterized by comprising the following raw materials in parts by weight (kilogram): SiO 2₂:35、ZnO:12、Bi₂O₃:5.0、Al₂O₃:5.5、B₂O₃:25.0、Na₂CO₃:2.0、C_UO:0.5、TiO₂:0.5、P₂O₅:1.0；

Mixing the raw material components, adding the raw material components into a glass melting furnace, melting for 3 hours at the high temperature of 1150 ℃, cooling to 1020 ℃ and clarifying for 2 hours to prepare molten glass;

(2) a cold quenching process: directly putting the glass liquid with the clarified surface into water, performing cold quenching to obtain a crushed glass body, adding the crushed glass body into a ball mill, performing ball milling to obtain glass powder with the fineness of 0.07mm, and drying;

(3) a crystallization process: putting the green body into a high-temperature box type resistance furnace, and heating to 340 ℃ at room temperature at the speed of 8 ℃/min; then heating to 820 ℃ at the speed of 5 ℃/min, cooling to 450 ℃ at the speed of 3 ℃/min, and carrying out heat preservation and crystal growth for 3.5 h;

(5) and (3) annealing: cooling the crystallized glass at the speed of 7 ℃/min, naturally cooling and rolling when the temperature is reduced to 300 ℃, and then grinding into glass powder;

Further, the binder was PVA, which was used in an amount of 3% by mass of the glass frit obtained in step (5).

Furthermore, the sealing glass ceramics are used for sealing the metal shell of the electronic component;

example two:

(3) a crystallization process: putting the green body into a high-temperature box type resistance furnace, and heating to 340 ℃ at room temperature at the speed of 8 ℃/min; then raising the temperature to 820 ℃ at the speed of 5 ℃/min, and adding graphene and B₂O₃The mass ratio of the graphene to the graphene is 1:0.9, the temperature is reduced to 450 ℃ at the speed of 3 ℃/min, and the crystal growth is carried out for 3.5 hours in a heat preservation way;

example three:

(1) a smelting process: the sealing glass ceramics with high expansion coefficient is characterized by comprising the following raw materials in parts by weight (kilogram): SiO 2₂:45、ZnO:12、Bi₂O₃:8.0、Al₂O₃:5.5、B₂O₃:7.0、Na₂CO₃:2.0、C_UO:0.5、TiO₂:0.5、P₂O₅:1.0；

Mixing the raw material components, adding the raw material components into a glass melting furnace, melting for 2 hours at the high temperature of 1150 ℃, and then cooling to 1020 ℃ for clarification for 1.6 hours to prepare glass liquid;

(2) a cold quenching process: directly putting the glass liquid with the clarified surface into water, performing cold quenching to obtain a crushed glass body, adding the crushed glass body into a ball mill, performing ball milling to obtain glass powder with the fineness of 0.05mm, and drying;

(3) a crystallization process: putting the green body into a high-temperature box type resistance furnace, and heating to 300 ℃ at room temperature at the speed of 7 ℃/min; heating to 750 deg.C at 3 deg.C/min, adding graphene and B₂O₃The mass ratio of the graphene to the graphene is 1:0.2, the temperature is reduced to 480 ℃ at the speed of 1 ℃/min, and the crystal growth is carried out for 3 hours in a heat preservation way;

(5) and (3) annealing: cooling the crystallized glass at the speed of 5 ℃/min, naturally cooling and rolling when the temperature is reduced to 250 ℃, and then grinding into glass powder;

Further, the binder is PEG, and the using amount of the PEG is 1% by mass of the glass powder obtained in the step (5).

Further, the sealing glass ceramics are used for sealing titanium alloy;

example four:

(1) a smelting process: the sealing glass ceramics with high expansion coefficient is characterized by comprising the following raw materials in parts by weight (kilogram): SiO 2₂:40、ZnO:8、Bi₂O₃:10、Al₂O₃:6、B₂O₃:10、Na₂CO₃:2.5、C_UO:3、TiO₂:1.5、P₂O₅:2；

Mixing the raw material components, adding the raw material components into a glass melting furnace, melting at the high temperature of 1200 ℃ for 2.5 hours, cooling to 1050 ℃ and clarifying for 1.8 hours to prepare molten glass;

(2) a cold quenching process: directly putting the glass liquid with the clarified surface into water, performing cold quenching to obtain a crushed glass body, adding the crushed glass body into a ball mill, performing ball milling to obtain glass powder with the fineness of 0.06mm, and drying;

(3) a crystallization process: putting the green body into a high-temperature box type resistance furnace, and heating to 320 ℃ at the room temperature at the speed of 7.5 ℃/min; heating to 780 ℃ at the speed of 4 ℃/min, and adding graphene and B₂O₃The mass ratio of the graphene to the graphene is 1:0.5, the temperature is reduced to 460 ℃ at the speed of 2 ℃/min, and the crystal growth is carried out for 3.2 hours under the condition of heat preservation;

(5) and (3) annealing: cooling the crystallized glass at the speed of 6 ℃/min, naturally cooling and rolling when the temperature is reduced to 280 ℃, and then grinding the glass into glass powder;

Further, the binder was PVA, which was used in an amount of 2.5% by mass of the glass frit obtained in step (5).

Further, the sealing glass ceramics are used for sealing aluminum alloy;

in order to more intuitively show the advantages of the low-temperature crystallization process, a proper amount of B is adopted₂0₃Zn0 and Bi₂O₃Replacing part of components in the microcrystalline glass, performing low-temperature crystallization, adding no graphene in the crystallization process, and replacing B with single variable in the same process₂0₃Zn0 and Bi₂O₃The method of (1) is compared, namely:

the first embodiment is as follows: the invention adopts a process without adding graphene in the crystallization procedure;

comparative example one: adopting a contrast process without adding graphene in the crystallization process, and adding B₂0₃Alternative contrast processes;

comparative example two: adopting a comparison process without adding graphene in the crystallization process and replacing Zn 0;

comparative example three: adopts a contrast process without adding graphene in the crystallization process, and adds Bi₂O₃Alternative contrast processes;

table 1: analysis of influence factors of different components on low-temperature crystallization process

B₂0₃

Zn0

Bi₂O₃

Temperature of melting

Crystallization temperature

Coefficient of thermal expansion

Example one

+

1150-1220℃

450

5.91×10^-6℃^-1

Comparative example 1

-

+

1250-1350

Above 720

4.21×10^-6℃^-1

Comparative example No. two

+

-

+

1450-1550

Over 850 g

4.84×10^-6℃^-1

Comparative example No. three

+

-

1380-1460

More than 750

2.06×10^-6℃^-1

From the analysis of the experimental data in the above table, it can be seen that:

firstly, the method comprises the following steps: with the appropriate amount of B₂0₃Zn0 and Bi₂O₃The method has positive significance in the aspect of obtaining large reduction of the melting temperature and the crystallization temperature of the microcrystalline glass by replacing part of components in the microcrystalline glass, which is probably caused by the following reasons:

1. with a suitable amount of B₂0₃Replacing part of SiO₂Due to B₂0₃Can react with Si0₂The components form a network structure, so the viscosity of the glass can be reduced at high temperature, and the glass has certain fluxing action, and in addition, B₂0₃Can also improve the glassThermal stability, chemical stability of;

2. replacing the intermediate oxide, ZnO is used as the intermediate oxide and can form ZnO with free oxygen in the glass₄Thereby entering the glass structure to form a relatively fusible glass;

secondly, the method comprises the following steps: b is₂0₃Zn0 and Bi₂O₃Has certain promotion effect on the coefficient of thermal expansion of the system, wherein, Bi₂O₃The effect of improving the thermal expansion coefficient is better than that of Zn0 and B₂0₃Playing a main role;

thus, SiO-ZnO-Bi₂O₃-Al₂O₃-B₂O₃The glass system changes the components and the dosage of common glass ceramics and improves the expansion coefficient to a certain extent; and Bi₂O₃The effect of improving the thermal expansion coefficient is better than that of Zn0 and B₂0₃。

Furthermore, in order to more intuitively show the advantages of the low-temperature crystallization process, the method for low-temperature crystallization by adding graphene is compared with the method for replacing the same process by adopting single variable,

the first embodiment is as follows: graphene is not added in the crystallization process;

example two: based on the first embodiment, the highest amount of graphene is added in the crystallization process;

comparative example five: based on the first embodiment, the highest amount of graphene is added in the crystallization process;

comparative example six: based on the first embodiment, the minimum amount of graphene is added in the crystallization process;

comparative example seven: based on the first embodiment, the highest amount of graphene is added in the crystallization process, the crystallization temperature in the crystallization process is changed, and the crystallization temperature is increased from 450 ℃ to 750 ℃;

according to the sealing means of the prior art, the obtained glass blank is heated to be close to the sealing temperature for softening, and the sealing temperature is according to the corresponding crystallization temperature; specifically, sealing is performed in a nitrogen atmosphere, and after sealing, the sealing effect is tested according to the standard and test method described in GB 9622.1-9622.11, and the results are shown in table 2:

table 2: analysis of influence of graphene on thermal expansion coefficient and conductivity of glass system in low-temperature crystallization process

1. from the first example and the second example, it can be seen that: in the second embodiment, after the highest amount of graphene is added in the crystallization process, the formed glass system can improve the thermal expansion coefficient to a greater extent, can keep a certain insulating property, and is suitable for sealing metal shells of electronic components or titanium alloy or aluminum alloy;

2. the comparison of example one, example two, comparative example five and comparative example six shows that: after the graphene is added in the crystallization process, the addition amount of the graphene has a certain positive correlation with the conductivity, but the addition of the graphene has little influence on the insulation property of the glass;

secondly, the addition amount of the graphene is positively correlated with the thermal expansion coefficient; this may be caused by the special structure of graphene, since graphene is a single-layer sheet structure composed of carbon atoms, and is a hexagonal honeycomb-shaped planar thin film composed of carbon atoms with sp2 hybridized orbitals, and is a two-dimensional material with a thickness of only one carbon atom, the addition of graphene provides conditions for the formation of boron oxide crystals;

the boron oxide crystal can effectively avoid the transformation of a molecular boron-oxygen triangular body [ BO3] into a boron-oxygen tetrahedron [ BO4] in the high-temperature cooling process, prevent the occurrence of abnormal boron phenomenon and prevent the problem of minimal value of a thermal expansion coefficient caused by the abnormal boron phenomenon;

3. comparative example seven it can be seen that: although the highest amount of graphene is added in the crystallization process, the crystallization temperature of 750 ℃ in the crystallization process is far higher than the crystallization temperature of 450 ℃ of boron oxide, the crystallization condition is damaged, the temperature of the annealing process is reduced too fast, the formation of crystals is not facilitated, the crystals of the boron oxide cannot be formed, and the thermal expansion coefficient is low.

Further, to verify the above conclusion:

heating boron oxide to 450 ℃ for melting, carrying out heat preservation and crystal growth for 3-3.5h according to the glass preparation process of the invention after melting, carrying out cold extraction to normal temperature to obtain molecular amorphous boron oxide, carrying out electron microscope scanning as shown in figure 1,

scanning graphene by an electron microscope as shown in figure 2,

heating boron oxide to 450 ℃ for melting, adding graphene, carrying out heat preservation and crystal growth for 3-3.5h according to the glass preparation process of the invention after melting, carrying out cold extraction to normal temperature, carrying out electron microscope scanning as shown in figure 3,

from the electron microscope scans of FIGS. 1-3, it can be seen that: the boron oxide cooled after high-temperature melting and calcining is in an amorphous state and does not have a crystal structure; and the graphene is of a lamellar structure and does not have a crystal structure, boron oxide is heated to 450 ℃ for melting, and after the graphene is added, the glass preparation process according to the invention is insulated and crystallized for 3-3.5h, and is cold-extracted to normal temperature, and the boron oxide crystal structure is generated when the graphene is of the lamellar structure, so that the graphene can provide conditions for conversion from amorphous molecular boron oxide to crystalline boron oxide, and the technical problem that the crystalline boron oxide is obtained by slowly cooling glassy boron oxide is solved.

In summary, the following steps:

SiO-ZnO-Bi of the invention₂O₃-Al₂O₃-B₂O₃System glass with appropriate amount of B₂0₃Zn0 and Bi₂O₃Part of components in the microcrystalline glass are replaced, so that the melting temperature and the crystallization temperature of the microcrystalline glass are greatly reduced, the processing method of the sealing microcrystalline glass with lower crystallization temperature is obtained, and the energy consumption is reduced, so that the industrial application is facilitated;

the original insulating property of a glass system can be kept by creatively adding the graphene in the crystallization process, and the fact that the graphene can convert amorphous molecular boron oxide into crystalline boron oxide under the condition of low-temperature crystallization is surprisingly found out, the structure has a positive effect on the expansion coefficient, and the technical problem that the crystalline boron oxide is obtained by slowly cooling glassy boron oxide is solved,

Claims

1. The sealing glass ceramics with high expansion coefficient is characterized by comprising the following raw materials in parts by weight: SiO 2₂35 to 45 portions of ZnO, 2.5 to 12 portions of Bi₂O₃5.0 to 15.0 portions of Al₂O₃5.5-7.5 parts of B₂O₃7.0 to 15.0 portions of Na₂CO₃2.0-3.5 parts of C_U0.5-5.5 parts of O and TiO₂0.5-2.5 parts of P₂O₅1.0 to 3.0 portions.

2. A sealing glass-ceramic with high expansion coefficient according to claim 1, characterized in that the raw material further comprises graphene.

3. A sealing glass-ceramic with high expansion coefficient according to claim 2, characterized in that in the raw material B₂O₃The mass ratio of the graphene to the graphene is 1: 0.2-0.9.

4. A low-melting-point processing method of a sealing glass-ceramic with high expansion coefficient, which is used for preparing the sealing glass-ceramic with high expansion coefficient as claimed in any one of claims 2-3, and is characterized in that the processing method specifically comprises the following steps:

5. A low-melting-point processing method for sealing glass ceramics according to claim 4, characterized in that the binder is PVA or PEG, and the amount of the binder is 1-3% by mass of the glass powder obtained in the step (5).

6. A low-melting-point processing method for sealing glass ceramics according to claim 4, characterized in that the sealing glass ceramics is used for sealing metal shells of electronic components or titanium alloy or aluminum alloy.