KR900008590B1 - Method for producing glass-ceramic metrial - Google Patents

Abstract

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Description

Manufacturing method of high strength glass ceramic material with excellent wear resistance

1 is an organization picture of a glass ceramic material using a conventional blast furnace slag.

2 is a tissue photograph of the glass ceramic material according to the amount of serpentine.

Figure 3 is a tissue photograph of the glass ceramic material in accordance with the present invention.

The present invention relates to a method for producing a high strength, wear resistant material by improving the structure by adding serpentine rock when manufacturing a glass ceramic material using blast furnace slag.

In general, glass-ceramic material using blast furnace slag is conventional blast furnace slag composition (SiO ₂ : 35wt% (hereinafter referred to as "%"), CaO: 45%, Al ₂ O ₃ : 15% .MgO: 5% and other trace oxides) is added a large amount (more than 50%) of siliceous glass cosmetic material and a nucleus material is added to it to maintain the final composition range of SiO ₂ : 60% or more, casting and crystallization heat treatment The material produced by this method has been manufactured in the USSR, the UK, Australia and Japan.

However, the materials manufactured by this method have very low blast furnace slag cost (less than 50%), and additional raw materials must be added in large quantities, which leads to an increase in manufacturing cost and temporary formation of phases. The problem is that the density of the nucleating agent affects the strength and abrasion resistance of the material, making it difficult to express a reproducible material structure.

In view of this, a method has been proposed to solve the above problem by adding a rare rare earth oxide as a nucleating agent to adjust the growth rate and improve the structure of the formation phase. According to this method, the rare and rare earth elements introduced in the nucleation process have been proposed. The growth of crystals with a crystal plane results in the growth of crystals in the vertical direction on the back surface, which results in the formation of a structure in which adjacent crystals interlock with each other, thereby improving the mechanical properties of the material. However, rare and rare earth elements are expensive even though their function is excellent, and the reality of this material, which must be produced in large quantities, is not only economical but also difficult to obtain.

In addition, since a significant amount of additive elements are accompanied by a loss due to rain when melted at a high temperature, their use is limited only in special cases. Therefore, in order to solve such a problem, the present invention inevitably adds MgO in the form of serpentine rock, which is known to be disadvantageous in glass modifing oxide of glass network structure in glass ceramic manufacturing. By combining with the alumina contained to produce a new initial crystal phase as a primary phase to produce a high-strength glass ceramic material with excellent wear resistance, as described in detail as follows.

In other words, the present invention is blast furnace slag: 57-65%, silica sand: 25-30%, alumina pulmonary softening (-5): 4-5%, serpentine rock: 3.5-4.5% and chromium ore as a nucleating agent as an additive: 3-4 % And soda ash: 1.5-2.3% alone or in combination, the final composition ratio of SiO ₂ : 44-50%, Al ₂ O ₃ : 12-16%, CaO: 20-25%, MgO: 5.8-6.2%, Cr ₂ O ₃ : 1-1.4% and Fe ₂ O ₃ : It is composed of a composition to be composed of 1-4%.

MgO in the blast furnace slag, along with CaO, destroys the silica structure, and the ions move easily to reduce the amount of residual glass when crystallization occurs. However, MgO added as serpentine has low reproducibility, so it does not dissolve sufficiently in molten slag and reacts with surrounding aluminum oxide at high temperature to form hot crystallized phase such as spinel at an early stage. It acts as the nucleus of and plays the role of making crystal growth perpendicular to this plane.

When the amount of serpentine added is less than 3.5%, the interlocking phenomenon of the crystal structure is reduced, and when the amount of serpentine is more than 4.5%, the amount of serpentine added is preferably in the range of 3.5-4.5%.

The composition range of the SiO ₂ , Al ₂ O ₃ , CaO and MgO is limited in order to form the primary crystal phase as methyllite (Melilite), when the methyllite is induced to the initial crystal phase, the addition ratio of blast furnace slag There is an advantage to increase.

In particular, the present invention has the advantage that the rate of crystallization can be increased because the nucleation temperature and the crystal growth temperature are substantially matched since the primary formation is adjusted to the high temperature generation phase.

Hereinafter, the present invention will be described in detail through examples.

Example 1

In order to understand the effect of serpentine rock, the composition of serpentine rock containing 40% SiO ₂ and 35% MgO in molten slag with the composition shown in Table 1 in the crucible-embedded high frequency induction furnace made by processing electric arc electrode It was changed to 3.0%, 4.0%, and 5.0% to prepare a glass ceramic material, and then the structure thereof was observed and shown in FIG. 2.

At this time, the melting temperature of the ceramic was 1550 ℃, after the casting crystallization heat treatment temperature was 860 ℃ and time was 3 hours.

TABLE 1

(Unit: weight%)

As can be seen in FIG. 2, when the 3.0% serpentine is injected, crystal interlocking phenomena are hardly observed (FIG. 2a). On the other hand, in the case of adding 4.0% of serpentine rock in accordance with the present invention, a high-temperature crystallized phase is produced first in the initial stage of crystallization, and then a secondary and tertiary crystal phase is generated. As they grew, more severe interlocking of crystal phases (Figure 2b) was observed.

As the mechanical properties of the ceramic material can be predicted from the above-described tissue state, the addition of serpentine at 4.0% showed better mechanical properties, that is, bending strength, compressive strength, and hardness than the addition of 3.0% and 50%. .

Example 2

In order to observe the mechanical and microscopic picture of the glass ceramic material prepared according to the conventional method and the present invention, 40% of the conventional material prepared by adding V ₂ O ₅ as the nucleating agent and the molten slag in the composition of Table 1 above Mechanical properties of the invention prepared by adding 4.0% of serpentine containing SiO ₂ and 35% MgO were measured and the results are shown in Table 2 below. Shown in

TABLE 2

As shown in Table 2 and FIG. 1 and FIG. 3, the present invention material has superior mechanical properties, that is, bending strength, compressive strength and hardness, as compared to the conventional material, and the structure of FIG. Tissues before the tissue strengthening process [FIG. 1 a] and V ₂ O ₅ are more engaged than the conventional materials [FIG. 1 b] to which the nucleating agent is added.

This demonstrates the excellent mechanical properties of the present invention.

As described above, the present invention utilizes the low reproducibility of serpentine rock, which is added to the process of melting blast furnace slag as a main raw material and melting silica sand and other preparations, thereby inducing the initial production nuclei into spanel crystals. It is possible to manufacture glass ceramic materials with superior wear resistance and strength by growing primary crystal phases perpendicular to the surface of the nucleus, thereby increasing the wear resistance and strength. There is an effect that can be used.

Claims (1)

Final composition ratio of SiO ₂ : 44-50wt%, A ₂ O ₃ : 12-16wt%, CaO: 20-25wt%, MgO: 5.8-6.2wt%. Blast furnace slag: 57-65wt%, silica sand: 25-30wt%, alumina tailings: 4-5wt%, and serpentine rock: 3.5 to be Cr ₂ O ₃ : 1-1.4wt% and Fe ₂ O ₃ : 1-4wt% A method for producing a high-strength glass ceramic material having excellent wear resistance, characterized by melting and crystallization by adding or mixing chromium ore: 3-4% and soda ash: 1.5-2.3% alone or in combination to a mixture consisting of -4.5 wt%.

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