阅读说明：本技术 一种微粒复合铝磷玻璃材料的制备方法及其产品和应用 (Preparation method of particle composite aluminum-phosphorus glass material, product and application thereof ) 是由 赵高凌 朱钦塨 金俊腾 宋斌 韩高荣 于 2020-11-23 设计创作，主要内容包括：本发明公开了一种微粒复合铝磷玻璃材料的制备方法,包括：将制备铝磷玻璃的原材料混合,加热至初始温度A至所有原料完全熔融,得到铝磷玻璃熔体；将铝磷玻璃熔体降温至中间温度B后,将石英玻璃微纳颗粒分散于铝磷玻璃熔体中,搅拌均匀后倒入模具成型,再降温至热处理温度C保温一段时间,经后处理得到微粒复合铝磷玻璃材料；以铝磷玻璃的原材料的总重量与石英玻璃微纳颗粒的重量之和为100％计,石英玻璃微纳颗粒的添加量为0.1～0.5wt％。本发明公开的制备方法,在不改变铝磷玻璃性质、不降低其透明度的前提下,大幅提升了铝磷玻璃材料的硬度、刚度和化学稳定性,尤其适用于在制备电子玻璃以及光学玻璃中的应用。(The invention discloses a preparation method of a particle composite aluminum-phosphorus glass material, which comprises the following steps: mixing raw materials for preparing the aluminum-phosphorus glass, and heating to an initial temperature A until all the raw materials are completely melted to obtain an aluminum-phosphorus glass melt; cooling the aluminum-phosphorus glass melt to an intermediate temperature B, dispersing the quartz glass micro-nano particles in the aluminum-phosphorus glass melt, stirring uniformly, pouring into a mold for molding, cooling to a heat treatment temperature C, preserving heat for a period of time, and performing post-treatment to obtain a particle composite aluminum-phosphorus glass material; the addition amount of the quartz glass micro-nano particles is 0.1-0.5 wt% based on 100% of the total weight of the raw materials of the aluminum-phosphorus glass and the weight of the quartz glass micro-nano particles. The preparation method disclosed by the invention greatly improves the hardness, rigidity and chemical stability of the aluminum-phosphorus glass material on the premise of not changing the properties of the aluminum-phosphorus glass and not reducing the transparency of the aluminum-phosphorus glass material, and is particularly suitable for being applied to the preparation of electronic glass and optical glass.)

1. A preparation method of a particle composite aluminum-phosphorus glass material is characterized by comprising the following steps:

(1) mixing raw materials for preparing the aluminum-phosphorus glass, and heating to an initial temperature A until all the raw materials are completely melted to obtain an aluminum-phosphorus glass melt;

(2) cooling the aluminum-phosphorus glass melt prepared in the step (1) to an intermediate temperature B, dispersing quartz glass micro-nano particles in the aluminum-phosphorus glass melt, uniformly stirring, pouring into a mold for molding, cooling to a heat treatment temperature C, preserving heat for a period of time, and performing post-treatment to obtain the particle composite aluminum-phosphorus glass material;

the addition amount of the quartz glass micro-nano particles is 0.1-0.5 wt% based on 100% of the sum of the total weight of the raw materials of the aluminum-phosphorus glass and the weight of the quartz glass micro-nano particles.

2. The method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (1):

the raw materials for preparing the aluminum-phosphorus glass comprise the following components in percentage by weight on the basis of oxides:

3. the method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (1):

the initial temperature A is 1400-1600 ℃, and the heat preservation time is 1-3 h.

4. The method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (2):

the average particle size of the quartz glass micro-nano particles is 100-300 nm;

and the quartz glass micro-nano particles are dispersed in the aluminum-phosphorus glass melt after atomization.

5. The method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (2):

the quartz glass micro-nano particles take oxides as a reference, and comprise the following raw materials in percentage by weight:

SiO₂ 95～99％；

Na₂O 1～5％。

6. the method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (2):

the temperature difference between the initial temperature A and the intermediate temperature B is 100-120 ℃;

and dispersing the quartz glass micro-nano particles into the aluminum-phosphorus glass melt after doping for a plurality of times, and controlling the heat preservation time at the intermediate temperature B to be 10-15 min.

7. The method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (2):

the heat treatment temperature C is 540-560 ℃, and the heat preservation time is 20-30 min.

8. The method for producing a particulate composite aluminum-phosphorus glass material according to claim 1, wherein in the step (2):

the post-processing includes cooling, grinding and polishing.

9. A particulate composite aluminium phosphorus glass material produced by the method of any one of claims 1 to 8.

10. Use of the particulate composite alumino-phosphorous glass material according to claim 9 in the preparation of electronic or optical glass.

Technical Field

The invention relates to the technical field of aluminum-phosphorus glass materials, in particular to a preparation method of a particle composite aluminum-phosphorus glass material, a product thereof and application in preparing electronic glass and optical glass.

Background

Phosphate glass systems are one of the most widely used glass systems at present, and can be used for electronic glass, optical glass, bioglass and other special glass by combining network formers such as silicon oxide, antimony oxide and the like or intermediates/modifiers such as aluminum oxide, sodium oxide, magnesium oxide and the like. The addition of the intermediate alumina can stabilize the structure of the phosphorus-oxygen glass and improve the network density and connectivity of the phosphorus-oxygen glass, so that the phosphorus-aluminum glass is widely applied to electronic devices, lasers, bone fillers and the like, but the residual stress of the aluminum-phosphorus glass is difficult to eliminate and the viscosity of the aluminum-phosphorus glass is increased due to the uneven angles and bond lengths of the aluminum-oxygen network structure, so that the aluminum-phosphorus glass is easy to have the defects of microcracks, bubbles, stones and the like.

At present, most methods for improving the performance of the phosphorus-aluminum glass are to add alkaline earth metal oxides, such as calcium oxide and magnesium oxide, into the glass components, and to introduce metal ions into the glass network structure to improve the compactness of the glass network, so as to improve the hardness, rigidity and chemical stability of the glass. However, in the conventional process of improving the glass performance, the brittleness of the glass is greatly improved while the hardness and the rigidity of the glass are improved, and a plurality of catastrophic structural failures are caused due to sudden failures. Or the hardness and rigidity of the phosphorus-aluminum glass are improved by adding silica with a larger weight fraction (more than 10%) to the glass component. However, the network structure of the aluminum-phosphorus glass is changed, and the optical properties of the aluminum-phosphorus glass, such as ultraviolet transmittance, infrared absorption and the like, are further influenced. In addition, the addition of a large amount of silicon dioxide can cause the conversion of a pure glass phase into a glass-ceramic phase, greatly influences the transparency of the phosphorus-aluminum glass, and limits the application of the phosphorus-aluminum glass in the fields of electronic glass, optical glass and the like.

Therefore, it is very urgent and desirable to develop a preparation process capable of improving the hardness, rigidity and chemical stability of the phosphorus-aluminum system without changing the structure and properties of the aluminum-phosphorus network.

Disclosure of Invention

Aiming at the problems in the prior art, the invention discloses a preparation method of a particle composite aluminum-phosphorus glass material, which greatly improves the hardness, rigidity and chemical stability of the aluminum-phosphorus glass material on the premise of not changing the properties of the aluminum-phosphorus glass and not reducing the transparency of the aluminum-phosphorus glass material, and is particularly suitable for being applied to the preparation of electronic glass and optical glass.

The specific technical scheme is as follows:

a method for preparing a particle composite aluminum-phosphorus glass material comprises the following steps:

(1) mixing raw materials for preparing the aluminum-phosphorus glass, and heating to an initial temperature A until all the raw materials are completely melted to obtain an aluminum-phosphorus glass melt;

(2) cooling the aluminum-phosphorus glass melt prepared in the step (1) to an intermediate temperature B, dispersing quartz glass micro-nano particles in the aluminum-phosphorus glass melt, uniformly stirring, pouring into a mold for molding, cooling to a heat treatment temperature C, preserving heat for a period of time, and performing post-treatment to obtain the particle composite aluminum-phosphorus glass material;

the addition amount of the quartz glass micro-nano particles is 0.1-0.5 wt% based on 100% of the sum of the total weight of the raw materials of the aluminum-phosphorus glass and the weight of the quartz glass micro-nano particles.

The invention discloses a method for compounding pre-prepared quartz glass micro-nano particles into Al in the form of particles by taking the pre-prepared quartz glass micro-nano particles as raw materials for the first time₂O₃-P₂O₅In the glass, the combination of the aluminum and the phosphorus is promoted by further heat treatment, so that the composite aluminum-phosphorus glass material with high hardness, high rigidity and excellent chemical stability is obtained. Compared with the prior art, the method has the advantages that the oxide SiO is directly added₂With Al₂O₃、P₂O₅The processes for preparing the composite aluminum-phosphorus glass material by melting and heating other raw materials are completely different, and the hardness, the rigidity and the chemical stability of the aluminum-phosphorus glass can be obviously improved only by adding 0.1-0.5 wt% of the total weight of the raw materials, so that the problems of changing the properties of the aluminum-phosphorus glass and reducing the transparency of the aluminum-phosphorus glass can be completely avoided.

In the step (1):

the raw materials for preparing the aluminum-phosphorus glass comprise the following components in percentage by weight on the basis of oxides:

the initial temperature a is only required to be sufficient to completely melt all the raw materials. Preferably, the initial temperature A is selected from 1400 to 1600 ℃.

The heat preservation time of the initial temperature A can be adjusted according to the initial temperature, and if the initial temperature A is higher, the heat preservation time can be properly reduced; the lower the initial temperature A, the longer the incubation time can be increased appropriately. The preferable heat preservation time is 1-3 h.

In the step (2):

the quartz glass micro-nano particles take oxides as a reference, and comprise the following raw materials in percentage by weight:

SiO₂ 95～99％；

Na₂O 1～5％。

the preparation method of the quartz glass micro-nano particles has no special requirements, and can be realized by adopting conventional technical means in the field, such as:

1) melting the raw materials according to the proportion, keeping the temperature at 1600-1650 ℃, pouring the raw materials into a mould for forming after heat preservation for 0.5-1 h;

2) after molding, putting the glass into a muffle furnace, keeping the temperature at 800-850 ℃ for 20-30 min, and cooling to obtain a quartz glass material;

3) and crushing and grinding the quartz glass material to obtain the quartz glass micro-nano particles.

Tests show that the average particle size of the crushed and ground quartz glass micro-nano particles has an important influence on the forming of the composite phosphorus-aluminum glass, if the average particle size is too large, the composite quartz particles are unevenly distributed in the aluminum-phosphorus glass, and the interface of the composite quartz particles and the aluminum-phosphorus glass is easy to become a crack source, so that the formed glass generates large-area cracks; if the average particle size is too small, the quartz glass micro-nano particles are easy to segregate under the action of the surface tension of the phosphorus-aluminum glass liquid, and the defects of crystallization, calculus and the like are caused. Preferably, the average particle size of the quartz glass micro-nano particles is 100-300 nm.

Preferably, the temperature difference between the initial temperature A and the intermediate temperature B is 100-120 ℃; tests show that the selection of the temperature difference range is crucial to the performance of the finally prepared composite aluminum-phosphorus glass material, and if the temperature difference is too large, large-area cracks can be caused in the formed glass; if the temperature difference is too small, the quartz glass micro-nano particles can be fused into a phosphorus-aluminum matrix glass network structure, and the effect of improving the performance of particles cannot be achieved. The variation of the temperature difference is strictly controlled.

Besides controlling the temperature difference change between the initial temperature A and the intermediate temperature B, the time required for the quartz glass micro-nano particles to be uniformly dispersed in the aluminum-phosphorus glass melt, namely the heat preservation time at the intermediate temperature B, needs to be strictly controlled at the same time. Tests show that if the heat preservation time is too short, the quartz glass micro-nano particles are unevenly dispersed in the aluminum-phosphorus glass melt, so that glass is devitrified or large-area cracks appear; if the heat preservation time is too long, the rigidity of the composite aluminum-phosphorus glass material is obviously reduced. Preferably, the heat preservation time at the intermediate temperature B is controlled to be 10-15 min.

The quartz glass micro-nano particles are dispersed in the aluminum-phosphorus glass melt after atomization, and the purpose of atomization is to ensure that the quartz glass micro-nano particles are uniformly distributed in the aluminum-phosphorus glass melt, but the particle size of the quartz glass micro-nano particles is not changed.

Preferably, the atomized quartz glass micro-nano particles are dispersed in the aluminum-phosphorus glass melt after being doped for a plurality of times, and the number of times is 2-5 times. After each doping, mechanical stirring is matched for a period of time so as to be convenient for uniform dispersion of the quartz glass micro-nano particles, and the doping times and the mechanical stirring time after each doping are adjusted according to different average particle diameters of the quartz glass micro-nano particles. Generally, the larger the average particle size of the quartz glass micro-nano particles is, the fewer the doping times are, and the longer the time interval is; and the smaller the average particle size of the quartz glass micro-nano particles is, the more the doping times are, and the shorter the time interval is.

Preferably, the heat treatment temperature C is 540-560 ℃, and the heat preservation time is 20-30 min. Different from the annealing temperature of the conventional aluminum phosphorus glass, the heat preservation treatment for a specific time at the heat treatment temperature can promote the elimination of the interface between the quartz glass micro-nano particles and the matrix glass, the transparency of the aluminum phosphorus glass cannot be reduced, and the residual stress can be eliminated. Tests show that the heat treatment temperature C and the heat preservation time are also very critical, and if the temperature is too high or the heat preservation time is too long, the quartz glass micro-nano particles are used as crystal nuclei, so that crystallization is easily caused; if the temperature is too low, the interface defect between the particles and the matrix glass cannot be eliminated, and the heat preservation time is too short, so that large-area cracks appear in the glass.

The post-processing includes cooling, grinding and polishing.

The invention also discloses the particle composite aluminum-phosphorus glass material prepared by the method, the composite material still maintains the original properties of the aluminum-phosphorus glass, but the rigidity is obviously improved, and the particle composite aluminum-phosphorus glass material is particularly suitable for being applied to preparing electronic glass or optical glass.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a preparation process of a particle composite aluminum-phosphorus glass material, which is characterized in that quartz glass micro-nano particles are directly added into an aluminum-phosphorus glass melt in an extremely low addition amount (0.1-0.5 wt%), so that the hardness, the rigidity and the chemical stability of the aluminum-phosphorus glass material are greatly improved on the premise of not changing the properties of the aluminum-phosphorus glass and not reducing the transparency of the aluminum-phosphorus glass material. The key point for realizing the purposes of the invention is as follows: firstly, controlling the average particle size of the quartz glass micro-nano particles within a certain range; secondly, controlling the temperature difference between the intermediate temperature B and the initial temperature A within a specific range, and controlling the heat preservation time at the intermediate temperature B within the specific range; the heat treatment temperature C and the holding time are controlled within specific ranges again. Experiments show that the aim of the invention can be ensured only when the parameters are limited within a specific range.

Tests prove that the particle composite aluminum-phosphorus glass material prepared by the invention keeps the aluminum-phosphorus network structure and the properties thereof, is still a uniform and transparent glass sample, but the hardness and the rigidity are obviously improved, and the elastic modulus can reach 78GPa at most.

Drawings

FIG. 1 shows XRD patterns of products prepared in comparative example 1 and examples 1 to 3, respectively.

Fig. 2 is an XRD spectrum of the products prepared in comparative example 2, comparative example 6 and comparative example 8, respectively.

Detailed Description

The present invention is further illustrated by the following specific examples, but the scope of the present invention is not limited to the following examples.

Example 1

SiO₂And Na₂CO₃With (SiO)₂：Na₂Weighing O95: 5) in a mass fraction ratio, placing the mixture in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; and then placing the corundum crucible into a high-temperature box type furnace, preserving heat for 1h at 1640 ℃, taking out the molten glass, pouring the molten glass into a mold, placing the mold into a muffle furnace after molding, preserving heat for 20min at 800 ℃, cooling and crushing the molten glass, and grinding the molten glass into quartz glass micro-nano particles with the average particle size of 300nm in a planet ball mill.

NH₄H₂PO₄，Al₂O₃，Li₂CO₃，MgCO₃With (P)₂O₅：Al₂O₃：Li₂O: accurately weighing MgO (71: 22:2:5) in a mass ratio, placing the weighed MgO in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; then placing the corundum crucible into a glass melting furnace (containing a stirring mechanism), and preserving heat for 2 hours at 1400 ℃; then cooling the aluminum-phosphorus glass liquid to 1300 ℃, and dividing the quartz glass micro-nano particles into three times by a high-temperature nozzle after the quartz glass micro-nano particles pass through an air-actuated atomization device, wherein the three times are according to the aluminum-phosphorus glass material: doping quartz glass material into molten glass according to the proportion of 99.9:0.1, simultaneously starting a stirring mechanism at the rotation speed of 30rpm, stirring for 5min after each doping, and controlling the doping process to be completed within 15 min; after the doping is finished, pouring the glass liquid into a mould for forming,and then putting the glass into a muffle furnace, preserving the heat at 540 ℃ for 20min, and cooling to obtain the particle composite aluminum-phosphorus glass material.

Example 2

SiO₂And Na₂CO₃With (SiO)₂：Na₂Weighing O95: 5) in a mass fraction ratio, placing the mixture in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; and then placing the corundum crucible into a high-temperature box type furnace, preserving heat for 1h at 1640 ℃, taking out the glass liquid, pouring the glass liquid into a mold, placing the mold into a muffle furnace after molding, preserving heat for 20min at 800 ℃, cooling, crushing, grinding, and grinding the glass liquid into quartz glass micro-nano particles with the average particle size of 200nm in a planet ball mill.

NH₄H₂PO₄，Al₂O₃，Li₂CO₃，MgCO₃With (P)₂O₅：Al₂O₃：Li₂O: accurately weighing MgO (71: 22:2:5) in a mass ratio, placing the weighed MgO in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; then placing the corundum crucible into a glass melting furnace (containing a stirring mechanism), and preserving heat for 2 hours at 1400 ℃; then cooling the aluminum-phosphorus glass liquid to 1280 ℃, and dividing the quartz glass micro-nano particles into four times by a high-temperature nozzle after the quartz glass micro-nano particles pass through a pneumatic atomization device, wherein the four times are according to aluminum-phosphorus glass materials: doping the quartz glass micro-nano particles into molten glass according to the proportion of 99.9:0.1, simultaneously starting a stirring mechanism at the rotation speed of 30rpm, stirring for 3min after each doping, and controlling the doping process to be completed within 12 min; and after doping is finished, pouring the molten glass into a mold for molding, then putting the mold into a muffle furnace, preserving the heat at 540 ℃ for 20min, and cooling to obtain the particle composite aluminum-phosphorus glass material.

Example 3

SiO₂And Na₂CO₃With (SiO)₂：Na₂Weighing O95: 5) in a mass fraction ratio, placing the mixture in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; then putting the corundum crucible into a high-temperature box type furnace, preserving heat for 1h at 1640 ℃, taking out the glass liquid, pouring the glass liquid into a mold, forming, putting the mold into a muffle furnace, preserving heat for 20min at 800 ℃, cooling, crushing, grinding, and putting the mixture into a planetary ball millGrinding the quartz glass particles into quartz glass micro-nano particles with the average particle size of 100 nm.

NH₄H₂PO₄，Al₂O₃，Li₂CO₃，MgCO₃With (P)₂O₅：Al₂O₃：Li₂O: accurately weighing MgO (71: 22:2:5) in a mass ratio, placing the weighed MgO in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; then placing the corundum crucible into a glass melting furnace (containing a stirring mechanism), and preserving heat for 2 hours at 1400 ℃; then cooling the aluminum-phosphorus glass liquid to 1300 ℃, dividing the quartz glass micro-nano particles into five times by a high-temperature nozzle after the quartz glass micro-nano particles pass through a pneumatic atomization device, and according to the aluminum-phosphorus glass material: doping the quartz glass micro-nano particles into molten glass according to the proportion of 99.5:0.5, simultaneously starting a stirring mechanism at the rotation speed of 30rpm, stirring for 2min after each doping, and controlling the doping process to be completed within 10 min; and after doping is finished, pouring the molten glass into a mold for molding, then placing the mold into a muffle furnace, preserving the heat at 560 ℃ for 20min, and cooling to obtain the particle composite aluminum-phosphorus glass material.

Comparative example 1

NH₄H₂PO₄，Al₂O₃，Li₂CO₃，MgCO₃With (P)₂O₅：Al₂O₃：Li₂O: accurately weighing MgO (71: 22:2:5) in a mass ratio, placing the weighed MgO in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; the corundum crucible was then placed in a glass melting furnace (containing a stirring mechanism) and held at 1400 ℃ for 2 h. And pouring the molten glass into a mold for molding, then placing the mold into a muffle furnace, preserving the heat at 500 ℃ for 20min, and cooling to obtain the matrix aluminum-phosphorus glass material.

Fig. 1 is an XRD pattern of the products prepared in comparative example 1 and examples 1 to 3, respectively, and it can be found by observing the XRD patterns in the patterns are all steamed bread peaks with glass characteristics, and the quartz glass micro-nano particles are directly added into the aluminum-phosphorus glass melt in an extremely low addition amount (0.1 to 0.5 wt%) to finally prepare the fine particle composite aluminum-phosphorus glass material which is not crystallized and is still a uniform and transparent glass sample.

Comparative example 2

NH₄H₂PO₄，Al₂O₃，Li₂CO₃，MgCO₃With (P)₂O₅：Al₂O₃：Li₂O: accurately weighing MgO (71: 22:2:5) in a mass ratio, placing the weighed MgO in an agate mortar for even dispersion, and pouring the mixture into a corundum crucible; the corundum crucible was then placed in a glass melting furnace (containing a stirring mechanism) and held at 1400 ℃ for 2 h. And pouring the molten glass into a mold for molding, then putting the mold into a muffle furnace, preserving the heat at 540 ℃ for 20min, and cooling to obtain the matrix aluminum-phosphorus glass material.

Comparative example 3

The preparation process is the same as that in example 1, except that the temperature of the aluminum-phosphorus glass liquid is reduced to 1320 ℃, namely the temperature difference between the initial temperature A and the intermediate temperature B is controlled to be 80 ℃.

Comparative example 4

The preparation process is the same as that in example 1, except that the temperature of the aluminum-phosphorus glass liquid is reduced to 1260 ℃, namely, the temperature difference between the initial temperature A and the intermediate temperature B is controlled to be 140 ℃.

Comparative example 5

The preparation process is the same as that in the example 1, and the difference is that the quartz glass micro-nano particles are completely dispersed in the glass melt within 18min by a high-temperature nozzle after passing through the pneumatic atomization device.

Comparative example 6

The preparation process is the same as that in example 1, except that the quartz glass micro-nano particles are ground into particles with the average particle size of 400nm in the preparation process.

Comparative examples 7 to 8

The preparation process was the same as in example 1, except that after the doping was completed, the glasses were placed in muffle furnaces and held at 550 ℃ for 10min and 40min, respectively.

Fig. 2 is XRD patterns of products prepared in comparative example 2, comparative example 6 and comparative example 8, respectively, and observation of the XRD patterns in the patterns shows that all the XRD patterns have obvious crystal peaks, which indicates that inappropriate process parameters can cause glass devitrification induced by the quartz glass micro-nano particles.

The mechanical properties and the macro morphology of the products prepared in the above examples and comparative examples are characterized, wherein the mechanical properties are characterized by using an ultrasonic echo material characterization system, and the results are respectively shown in tables 1 and 2 below.

TABLE 1

	Example 1	Example 2	Example 3
				Bulk modulus (Gpa)	48.2953	48.717	44.5659
Shear modulus (GPa)	29.5181	31.4632	30.328
				Poisson ratio	0.2461	0.2343	0.2227
Modulus of elasticity (GPa)	73.5663	77.6691	74.1612
				Macroscopic morphology of glass	Homogenizing and clarifying	Homogenizing and clarifying	Homogenizing and clarifying

TABLE 2

	Comparative example 1	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 7
						Bulk modulus (Gpa)	40.631	40.4135	-	41.105	-
Shear modulus (GPa)	23.3755	23.0179	-	23.2103	-
						Poisson ratio	0.2586	0.2607	-	0.2624	-
Modulus of elasticity (GPa)	58.8422	58.0356	-	58.6011	-
						Macroscopic morphology of glass	Homogenizing and clarifying	Homogenizing and clarifying	Large area of cracks	Homogenizing and clarifying	Large area of cracks

Further, it will be understood that various changes and modifications may be made by one skilled in the art after reading the disclosure herein, and equivalents may fall within the scope of the invention as defined by the appended claims.