CN103663982A - Low-fluorine microcrystalline glass - Google Patents

Abstract

The invention provides a low-fluorine glass-ceramic, which comprises the following components by weight percentage: 56%<silicon dioxide<72%, 8%<potassium oxide≤12%, 18%<calcium oxide≤20%, 1% ≤ Fluorine ≤ 3%, 1% < alumina ≤ 5%, 0 < zinc oxide ≤ 4%, 0 < titanium oxide ≤ 2%, the balance is sodium oxide. The low-fluorine glass-ceramic provided by the present invention presents a translucent jade-like appearance, has the moistness and waxy texture of natural jade, has a fine texture, is crystal clear, has no radiation, and has good toughness and high strength, and is easy to further process and shape, and can be widely used It is used in high-grade stone substitutes and other fields.

Description

A low-fluorine glass-ceramic

technical field

The invention relates to the field of glass-ceramics, in particular to a low-fluorine glass-ceramic.

Background technique

With the steady and continuous development of my country's national economy, people's living standards are improving, and the demand for high-grade building materials is increasing, especially the demand for alternative products of non-radiation high-grade stone is more urgent, but domestic high-grade stone substitute products are brittle. It is not easy to process and shape, so many high-grade stone materials need to be imported from abroad, and the cost is greatly increased.

Glass-ceramics, also known as ceramic glass, has dual characteristics of glass and ceramics. Glass-ceramics is composed of crystals with regular atomic arrangements. Therefore, glass-ceramics has higher brightness than ceramics and stronger toughness than glass. Glass-ceramic combines the triple advantages of glass, ceramics and natural stone. It is superior to natural stone and ceramics. It can be used for building curtain walls and indoor high-end decorations. It can also be used as structural materials for machinery, insulating materials for electronics and electricians, and large-scale Integrated circuit bottom plate materials, microwave heat cracking-resistant utensils, chemical and anti-corrosion materials, and mine wear-resistant materials, etc., have become ideal substitutes for high-grade stone materials.

Most of the existing glass-ceramics are high-fluorine glass products. Due to the serious volatilization of fluorine in the production, the stability of production is not easy to control, resulting in a low success rate of glass-ceramics production. Even if glass-ceramics is successfully produced, there are still problems. Single tone, no texture, high surface porosity, low production stability and high brittleness, not easy to process and shape, etc., and high-fluorine glass products severely corrode the kiln during the production process, resulting in shortened service life of the kiln and high production costs. increase.

Contents of the invention

The technical problem to be solved by the present invention is to provide a low-fluorine glass-ceramic with delicate texture, crystal clear, good toughness and high strength.

In order to solve the above technical problems, the low-fluorine glass-ceramic provided by the present invention comprises the following components by weight percentage: 56%<silicon dioxide<72%, 8%<potassium oxide≤12%, 18%<calcium oxide≤20% , 1% ≤ fluorine ≤ 3%, 1% < aluminum oxide ≤ 5%, 0 < zinc oxide ≤ 4%, 0 < titanium oxide ≤ 2%, and the balance is sodium oxide.

Each composition of glass-ceramic provided by the present invention is defined as follows by weight percentage:

Silica endows glass-ceramics with good chemical and thermal stability, can increase the strength of glass-ceramics and reduce the expansion coefficient of glass-ceramics, but as the content increases, the viscosity of glass liquid will increase, and the micro The melting temperature of crystal glass rises, so the content of silicon dioxide is set as: 56%<silicon dioxide<72%.

Potassium oxide is a good co-solvent, which can improve the gloss of glass-ceramics, promote the melting and clarification of glass liquid, and can also reduce the viscosity of glass liquid. Therefore, the content of potassium oxide is set as: 8% < potassium oxide ≤ 12% .

Calcium oxide can reduce the high-temperature viscosity of molten glass, promote the melting and clarification of molten glass, and increase the chemical stability, mechanical strength and hardness of glass-ceramics. Therefore, the content of calcium oxide is set as: 18% < calcium oxide ≤ 20%.

Fluorine is an excellent opacifying agent. When the fluorine content is too high, the production stability of glass-ceramics is low, the brittleness is high, and it is easy to devitrify. Therefore, the fluorine content is set as: 1%≤fluorine≤3%, more preferably , 1%≤fluorine<2%.

Alumina can reduce the crystallization tendency of glass-ceramics, improve chemical stability, mechanical strength and hardness, improve thermal stability, and reduce electrical insulation. However, as the content of alumina increases, it will cause stripes on the surface of glass-ceramics. And it will increase the viscosity of the molten glass, making it difficult to melt and clarify, and instead increase the tendency of crystallization, so the content of alumina is set as: 1% < alumina ≤ 5%.

Zinc oxide can improve the chemical stability of glass-ceramics and reduce the coefficient of thermal expansion of glass-ceramics, but with the increase of zinc oxide content, it will increase the crystallization tendency of glass-ceramics, so the content of zinc oxide is set as: 0< Zinc oxide≤4%.

Titanium oxide can reduce the coefficient of thermal expansion of glass-ceramic, but if it is introduced too much, it will increase the crystallization ability of glass-ceramic, so the content of titanium oxide is set as: 0<titanium oxide≤2%.

Sodium oxide can reduce the viscosity of molten glass and promote the melting and clarification of molten glass, so the remaining components of the glass-ceramics are set to be sodium oxide.

The fluorine content in the low-fluorine glass-ceramics of the present invention is low, and its low-fluorine, high-silicon, and high-calcium composition ratio is conducive to improving the stability and success rate of glass-ceramics production. The surface porosity of the low-fluorine glass-ceramics with the above-mentioned composition ratio Low, low water absorption, high impact toughness, high flexural and compressive strength, and strong processing and forming performance. The appearance of this low-fluorine glass-ceramic is translucent jade-like, with delicate texture and crystal clear.

Preferably, the main crystal phase of the low-fluorine glass-ceramics is Na _4~3 K _2-3 Ca ₅ (Si ₁₂ O ₃₀ )F ₄ , and this crystal phase is lath-shaped, which greatly improves the low-fluorine crystallite The toughness, flexural and compressive strength of glass, and easy processing and cutting.

Preferably, the impact toughness of the low-fluorine glass-ceramic is 5.0kj/cm ³ -5.6kj/cm ³ .

Preferably, the Mohs hardness of the low-fluorine glass-ceramic is 6.0-7.0.

Preferably, the flexural strength of the low-fluorine glass-ceramic is 65MPa-85MPa.

Preferably, the compressive strength of the low-fluorine glass-ceramic is 600MPa-700MPa.

Preferably, the volume density of the low-fluorine glass-ceramic is 2.5g/cm ³ -2.8g/cm ³ .

The low-fluorine glass-ceramic provided by the present invention presents a translucent jade-like appearance, has the moistness and waxy texture of natural jade, has a fine texture, is crystal clear, has no radiation, and has good toughness and high strength, and is easy to further process and shape, and can be widely used It is used in high-grade stone substitutes and other fields.

Detailed ways

In order to make the above objects, features and advantages of the invention more obvious and comprehensible, specific implementations of the invention will be described in detail below.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

Table 1 is a table of performance parameters of low-fluorine glass-ceramics under different compositions.

Under the condition of knowing the content of the specific components, the low-fluorine glass-ceramics of the present invention can be produced according to methods known in the art, preferably as follows:

1. Select one or more of quartz sand, soda ash, potassium carbonate, calcite, alumina, calcium fluoride, zinc oxide, and titanium oxide as raw materials to provide the composition of low-fluorine jade-like glass-ceramics, according to Table 1. The composition proportion of embodiment calculates the consumption of raw material, mixes after weighing and obtains base material;

2. Melt the base material at 1450℃～1500℃ for 16h～24h, and obtain glass liquid after clarification;

3. The molten glass is calendered at 1050°C to 1100°C to make a plate with a thickness of 5mm to 30mm;

4. Heat the plate at 650°C to 900°C for 6h to 12h for crystallization treatment, then cool and anneal with a fan to obtain low-fluorine glass-ceramic, more preferably at 650°C for 1 to 2 hours, and at 700°C for 1 to 2 hours 2h, 750°C for 1-2h, 800°C for 1-2h, 850°C for 1-2h and 900°C for 1-2h for crystallization.

Table 1

As shown in Table 1, the low-fluorine glass-ceramic of the present invention has high flexural and compressive strength, high hardness and strong impact toughness. The finished low-fluorine glass-ceramic has the moistness and waxy texture of natural jade, fine texture, crystal clear, and can be prepared into profiles of different sizes for easy processing.

Although the present invention is described in conjunction with the above embodiments, the present invention is not limited to the above embodiments, but is only limited by the appended claims, and those skilled in the art can easily modify and change it, but without departing from the spirit and scope of the present invention.

Claims (7)

1. one kind low fluorine devitrified glass, it is characterized in that, comprise by weight percentage following composition: 56% < silicon-dioxide < 72%, 8% < potassium oxide≤12%, 18% < calcium oxide≤20%, 1%≤fluorine≤3%, 1% < aluminum oxide≤5%, 0 < zinc oxide≤4%, 0 < titanium oxide≤2%, surplus is sodium oxide.

2. low fluorine devitrified glass according to claim 1, is characterized in that, the main crystalline phase of described low fluorine devitrified glass is Na _4～3k _2～3ca ₅(Si ₁₂o ₃₀) F ₄.

3. low fluorine devitrified glass according to claim 1, is characterized in that, the impelling strength of described low fluorine devitrified glass is 5.0kj/cm ³～5.6kj/cm ³.

4. low fluorine devitrified glass according to claim 1, is characterized in that, the Mohs' hardness of described low fluorine devitrified glass is 6.0～7.0.

5. low fluorine devitrified glass according to claim 1, is characterized in that, the folding strength of described low fluorine devitrified glass is 65MPa～85MPa.

6. low fluorine devitrified glass according to claim 1, is characterized in that, the ultimate compression strength of described low fluorine devitrified glass is 600MPa～700MPa.

7. low fluorine devitrified glass according to claim 1, is characterized in that, the volume density of described low fluorine devitrified glass is 2.5g/cm ³～2.8g/cm ³.