KR20150097357A - Method for tincting sapphire - Google Patents

Abstract

Provided is a method for tinting a specimen of synthetic and transparent single crystal sapphire uniformly a desired color. The method comprises steps of: putting metal oxide powder in the bottom of a heat-resistant crucible; arranging a plurality of the sapphire specimens at predetermined intervals above the metal oxide powder; putting the metal oxide powder once more by predetermined thickness to completely cover a plurality of the arranged sapphire specimens; making a junction uniformly between the sapphire specimens and the metal oxide powder; and tinting the sapphires specimens with the metal oxide powder by applying heat after covering the crucible with heat-resistant cover and placing in a heat treating furnace thereafter.

Description

{Method for tincting sapphire}

The present invention relates to a coloring method of sapphire, and more particularly to a technique for uniformly coloring a colorless transparent sapphire of artificial color having high hardness and a single crystal to a desired color.

In general, sapphire or quartz in a ceramic single crystal is a ceramic single crystal of Al ₂ O ₃ or SiO ₂ , and a small amount of impurities are mixed to form a color. Part of sapphire or quartz obtained in a natural state or a conventional sapphire single crystal Are colorless, uncolored and uneven in color, which can be of low value as jewels and may be of limited industrial application. Of course, colorless transparent artificial sapphire specimens have long been used as LED light-emitting substrates and often used as transparent protection windows for high-end watches.

Transparent ceramic monocrystals with good color are easy to be used for jewelry or industrial purposes as long as the specific colors are uniformly and economically available.

Therefore, in the related art, various attempts have been made to find a method of uniformly and economically imparting high quality color to a colorless or discolored ceramic single crystal. As a result, various attempts have been made to artificially color a ceramic single crystal A method has been proposed.

Conventional methods of coloring sapphire include a powder melting method, a flame melting method, an ion implantation method, and a thermal diffusion method.

For example, a powder melting method for producing a ceramic single crystal sapphire having a hue is a method in which a small amount of colored impurities is mixed into an Al ₂ O ₃ seed and an Al ₂ O ₃ powder of a ceramic single crystal, And the single crystal sapphire is grown to grow a sapphire ingot of a certain size. This method is incapable of uniformly growing the ingot due to the inclusion of impurities, Melting and growth equipment is liable to be contaminated with impurities, and once expensive equipment is contaminated, there is a disadvantage that it is difficult to make ceramic single crystals having different color or electrical characteristics under different conditions.

Another conventional sapphire coloring method has a disadvantage in that it is difficult to economically provide a uniform color in a large amount for various reasons.

For example, the coloring methods and conditions of these ceramic single crystals may vary depending on the method, conditions, and environment in which the colorless transparent ceramic single crystal to be colored is manufactured or grown naturally.

Furthermore, since there are various coloring methods depending on the working conditions of the coloring and the kinds and amounts of the coloring materials, various studies and tests have been conducted in various fields in order to overcome them.

Among the methods for solving such a problem, Korean Patent Registration No. 0497968 discloses a method for coloring natural or artificial single crystal, comprising the steps of: polishing a natural or artificial single crystal with a specimen having a predetermined shape; Placing a polished specimen on the boat in the polishing step, pouring the cobalt compound into the boat to set the entire surface of the single crystal specimen to cover the boat; A set boat is placed in an electric furnace and a vacuum or a predetermined amount of nitrogen gas is supplied to the furnace to raise the temperature to a predetermined temperature for a predetermined time and then to maintain the elevated maximum temperature for a predetermined period of time, ; And an immersion step of immersing the specimen after the heat treatment in the heat treatment step in a mixed solution to remove the cobalt compound residue on the specimen.

However, according to this method, as shown in FIG. 3, since the single crystal specimen is placed on the bottom of the boat and the cobalt compound is poured into the boat, the lower surface of the single crystal in contact with the single crystal specimen can not contact with the cobalt compound, There is a problem that the uniformity of the single crystal specimen is lowered. In particular, when a single crystal is formed into a sheet like a wafer for an LED substrate, the lower surface of the single crystal is widened, which makes it difficult to provide uniform color throughout the single crystal.

In particular, it discloses only a method of coloring one single crystal specimen. When a plurality of single crystal specimens for mass production are simultaneously processed, it is necessary to dispose a monocrystalline specimen in a certain structure for color uniformity, It has not been disclosed at all how to uniformly contact the entirety of the single crystal specimen.

In addition, there is a problem that the manufacturing process is complicated, such as vacuuming the inside of the electric furnace or supply of the oxygen-barrier gas during the heat treatment process, and expensive facilities suitable for this.

In addition, there is a lack of detailed description of cobalt compounds effective for color development, and there is no suggestion how to economically and effectively colorize them.

Accordingly, it is an object of the present invention to provide a method of coloring sapphire, in which a colorless transparent single crystal sapphire specimen of artificial coloring finally has color uniformity.

Another object of the present invention is to provide an economical method of coloring sapphire that can reliably ensure uniform coloring even when processing a plurality of artificial colorless transparent single crystal sapphire specimens at one time.

Another object of the present invention is to provide a colorless transparent single crystal sapphire specimen coloring method which is simple in manufacturing time or manufacturing process for coloring, simple and low cost, and can reduce equipment cost and manufacturing cost.

Another object of the present invention is to provide a method of coloring sapphire that lessens the heat treatment furnace during heat treatment.

Another object of the present invention is to provide a method of coloring sapphire which can mass-produce a colorant economically in large quantities in artificial colorless transparent single crystal sapphire specimens having a constant size and characteristics.

According to an aspect of the present invention, there is provided a method of coloring a single crystal transparent sapphire specimen of artificial leather, comprising the steps of: placing a metal oxide powder on the bottom of a heat resistant crucible; Disposing a plurality of the sapphire specimens on the metal oxide powder at predetermined intervals; Further comprising the step of inserting the metal oxide powder so that the plurality of arranged sapphire specimens are completely covered with a predetermined thickness; Making the plurality of sapphire specimens uniformly contact the metal oxide powder; And a step of covering the crucible with a heat-resistant lid, placing the crucible in a heat treatment furnace, and performing heat treatment so that the metal oxide powder colors the sapphire specimen.

According to another aspect of the present invention, there is provided a method of manufacturing a sapphire substrate, comprising: preparing a specimen of sapphire by cutting and polishing a colorless transparent synthetic single crystal sapphire ingot to a predetermined size; Placing the specimen in a heat-resistant crucible containing a metal oxide powder so that the specimen is completely covered with the metal oxide powder so that the metal oxide powder is uniformly in contact with the specimen as a whole; Placing the heat-resistant crucible on a heat-resistant lid, placing the heat-resistant lid in a heat treatment furnace and performing heat treatment; And vaporizing the vaporized vapor of the metal oxide powder by the heat treatment to diffuse into the specimen and coloring the vaporized color of the vaporized ion by the steam ion.

Preferably, the heat treatment may be performed in an oxidizing atmosphere.

Preferably, the heat treatment is performed in cycles of temperature rise, temperature holding and temperature lowering, and the temperature holding is performed at 800 to 1700 占 폚 for 1 to 20 hours.

Preferably, the diameter of the metal oxide powder is 0.06 mm or less on the basis of D50, and the purity of the metal oxide powder may be 90% or more.

Preferably, the specimen may be polished prior to placing the specimen of sapphire so that the surface is polished.

Preferably, the arrangement is transversal, and the entire outer surface is covered by the metal oxide powder.

Preferably, the step of disposing and further adding the metal oxide powder are repeated a predetermined number of times.

Preferably, the uniform contact can be made by vibration.

Preferably, the steam evaporated by the metal oxide powder during the heat treatment is filled in a part of the closed space defined by the lid and the crucible to increase the pressure, and the pressure causes the metal oxide powder to further have a physical pressure And the lid may cover the crucible so that the steam escapes partially during the heat treatment.

Preferably, vapor ions evaporated from the metal oxide powder by the heat treatment diffuse into the specimen and are colored with intrinsic color by the vapor ions, and the diffusion is solid diffusion.

Preferably, the diffusion may be achieved by exchanging metal ions of the metal oxide and metal ions of the sapphire specimen.

Preferably, the above specimen was transparent and colorless, the heat treatment is made in an oxidizing atmosphere, the metal oxide is chromium oxide or higher purity is 90% (CrO _3), cobalt oxide (Co ₃ O ₄₎ or the nickel oxide (NiO) , And the specimen is colored green, blue and sky blue, respectively.

Preferably, the particle size of the mixed metal oxide powder may be 0.08 mm or less on the basis of D50.

Preferably, the metal oxide powder may be a mixed metal oxide powder in which one metal oxide powder and another metal oxide powder are uniformly mixed, dried and crushed, and then calcined to form at least two intermetallic bonds.

Preferably, the colored specimen may be surface treated with a solution of either nitric acid, sulfuric acid or hydrochloric acid having a purity of 40% to 60% prior to the polishing.

Preferably, the step of polishing the surface of the colored sapphire specimen so as to have gloss may be further included.

According to the above-described configuration, since the crucible and the cover are heat treated in an oxidizing atmosphere, economical production is easy, so that mass production is easy and manufacturing cost is reduced.

In addition, the bonding between the lid and the crucible during the heat treatment is sufficient to discharge a part of the ion vapor generated inside the crucible, and accordingly, the coloring effect is improved and the heat treatment furnace is less contaminated.

In addition, since the metal oxide powder for coloring is reliably and uniformly positioned on the sapphire specimen, uniform and efficient coloring can be easily performed on all the surfaces of the sapphire specimen after the heat treatment for coloring.

In addition, since only particles of fine metal oxide powder having high purity are used, it is advantageous to provide uniform and efficient coloring on all sides of the sapphire specimen.

In addition, the colorless transparent monocrystalline sapphire specimen of artificial color is of sufficient value for jewelry and industrial use because it is colored because it is colored in its entirety as a uniform color.

1 is a flow chart for explaining a coloring method according to the present invention.
Fig. 2 shows an example of a specimen used in the present invention.
Figure 3 shows the arrangement of a specimen according to an example of the present invention.
Figure 4 shows the arrangement of specimens according to another example of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. The 'sapphire specimen' in the following description refers to a sapphire specimen of artificial colorless transparent single crystal, and may be a sapphire specimen having uniform dimensions and characteristics.

Fig. 1 is a flow chart for explaining a coloring method according to the present invention. Fig. 2 shows an example of a specimen used in the present invention, Fig. 3 shows the arrangement of a specimen according to an example of the present invention, Fig. 5 shows the arrangement of a specimen according to another example of the present invention.

As described, the coloring method according to the present invention includes the steps of supplying a metal oxide powder of fine size 100, a sample placing step 200, a metal oxide powder addition feeding step 300, a heat treatment step 400, (Step 500).

First, we explain the process of making sapphire specimens before coloring.

A sapphire ingot of a colorless transparent single crystal Al ₂ O ₃ manufactured by artificial manufacture was cut into a circular plate having a predetermined size, for example, a diameter of 50 mm and a thickness of 0.8 mm as shown in Fig. 2, The sample 30 is prepared.

Since the sapphire has a high hardness, it takes a lot of time for mass production. Therefore, the sapphire specimen can be manufactured in consideration of the shape of the final sapphire product in the process of forming the ingot.

For example, if a final emblem of a colored sapphire material is to be manufactured, an inner pottery made of the same material as the crucible and having a shape similar to an automobile emblem is inserted into the crucible for making the ingot, .

The sapphire ingot may be grown at a temperature of 2,000 DEG C or higher. The sapphire specimen 30 having the sapphire ingot cut may be made opaque by polishing the surface with a polished surface or without polishing. However, .

≪ Metal oxide powder supplying step (100) >

A fine metal oxide powder (40) is put in such a manner that the entire bottom floor inside the crucible (10) is uniformly covered. The uniform thickness of the metal oxide powder makes it possible to provide uniform coloring to the specimen 30.

The crucible 10 may be made of a heat-resistant polycrystalline ceramic material such as alumina, but it is not limited thereto. The crucible 10 may be made of a material that can withstand a heat treatment temperature of about 800 ° C. to 1700 ° C., have. In this embodiment, a polycrystalline alumina crucible in which both the crucible 10 and the lid 20 are sintered is used.

When polycrystalline ceramic material such as polycrystalline alumina crucible 10 is used as the crucible 10, the metal oxide powder 40 is put into the crucible 10 during the coloring process of the sapphire specimen 30, The interior of the crucible 10 can also be colored through solid diffusion similar to the specimen 30. [

The crucible 10 is suitably closed by the lid 20 so that a minute gap is formed between the crucible 10 and the lid 20 within a range where the pressure inside the crucible 10 is maintained at a predetermined value, The metal oxide powder 40 supplied to the metal oxide powder 40 is evaporated by heat and part of the generated vapor escapes, so that the internal pressure of the crucible 10 is excessively increased to prevent the crucible 10 from exploding.

On the other hand, if the sealing between the crucible 10 and the lid 20 is excessively loosened, the metal oxide powder 40 is evaporated due to heat and the generated vapor is easily released. Therefore, the efficiency of coloring is lowered, It may contaminate the heat treatment furnace.

As the metal oxide powder 40 for coloring the sapphire specimen 30, various kinds of metal oxide powder or various inorganic materials can be used. For example, in this embodiment, the particle size is 10 to 60 μm on the basis of D50, Chromium oxide (CrO ₃ ) powder of 90% or more is used.

≪ Sample placement step 200 >

3, a plurality of sapphire specimens 30 are disposed in the crucible 10. Preferably, the metal oxide powder 40 is poured on the bottom of the crucible 10 to a predetermined thickness and the upper surface is horizontally The sapphire specimens 30 are placed.

Here, since the uniform coloring of the test piece 30 is easily provided by the uniform thickness of the metal oxide powder 40, it is preferable to make the thickness of the powder 40 in contact with the test piece 30 as uniform as possible The present invention is not limited to this in order to improve the productivity.

≪ Metal oxide powder addition supply step 100 >

A predetermined amount of the metal oxide powder 40 is poured to completely cover the plurality of arranged sapphire specimens 30 to adjust to a constant thickness and to level the top surface as described above, By adding the amount of the metal oxide powder to be filled in the gap between the plurality of sapphire specimens 30 disposed thereon. A predetermined amount of the metal oxide powder 40 is used for the subsequent arrangement of the sapphire specimen 30 repeated in the same manner.

The sapphire specimen 30 is arranged in several layers by repeating the above process, and then the lid 20 is covered and the inside of the crucible 10 is sealed.

As described above, the uniform coloring of the test piece 30 is easily provided by the uniform thickness of the metal oxide powder 40, so that the thickness of the powder 40 in contact with the test piece 30 as much as possible is made uniform desirable.

In addition, the contact between the sapphire specimen 30 and the metal oxide powder 40 should be as much as possible. If the densities are uniform, color uniformity is ensured and workability and efficiency of coloring are improved.

For this purpose, the size of the metal oxide powder 40 is usually as uniform as possible and small as possible, but the present invention is not limited thereto since the working method and the type of the metal oxide powder 40 may differ.

3, when a plurality of sapphire specimens 30 are arranged on the upper surface of the metal oxide powder 40 whose thickness is controlled, the upper surface or lower surface of the sapphire specimen 30 and the metal oxide powder 40 The metal oxide powder 40 does not contact the sapphire specimen 30 at some portions, and a fine space 42 may occur. When the heat treatment is performed in the state where the space 42 exists, the amount of diffusion of the metal oxide powder 40 is different, so that the uniformity of coloring is lowered.

In order to prevent this, the crucible 10 may be selectively vibrated to remove the space on the underside of the sapphire specimen 30 which may be generated in some cases. That is, when the crucible 10 is placed on the vibration unit and the crucible 10 is vibrated by applying minute vibration, the space is collapsed by the vibration and filled with the metal oxide powder 40.

In this manner, the microscopic space 42 on the underside of the sapphire specimen 30, which may be caused by the vibrating unit, can be removed, but the reliability can not be completely ensured. This problem may exist at any time as long as the sapphire specimen 30 is placed horizontally.

Such a problem can be reliably brought into contact with the metal oxide powder 40 and the sapphire specimen 30 efficiently by vibrating the crucible 10 covered with the lid 20 by applying minute vibrations.

However, it is possible to consider a method of arranging the sapphire specimen 30 vertically in order to eliminate such a problem.

Referring to FIG. 4, the sapphire specimen 30 is arranged vertically upright inside the crucible 10. That is, the metal oxide powder 40 is poured to a predetermined thickness and a set of the sapphire specimens 30 are arranged in an upright position at a time. At this time, only a part of the sapphire specimen 30 is embedded in the metal oxide powder 40, and the upright state is not necessarily vertical.

Next, a predetermined amount of the metal oxide powder 40 is poured to cover the sapphire specimen 30, and another set of the sapphire specimen 30 is placed in an upright state in the same manner as described above.

Even in this case, if the crucible 10 is vibrated by applying minute vibration, the metal oxide powder 40 and the sapphire specimen 30 can be reliably and uniformly contacted much more efficiently.

The sapphire specimen 30 is placed upright in a plurality of layers by repeating the above process, and then the lid 20 is covered and the inside of the crucible 10 is sealed.

The metal oxide powder 40 and the sapphire specimen 30 can be reliably and uniformly contacted more efficiently by vibrating the crucible 10 covered with the lid 20 by applying minute vibrations.

According to this method, since the metal oxide powder 40 flows to the side surface of the upright sapphire specimen 30, there is less possibility that a fine space is formed between the side surface of the sapphire specimen 30 and the metal oxide powder 40.

According to the above-described manufacturing method, the metal oxide powder 40 for coloring is reliably and uniformly placed on all the surfaces of the sapphire specimen 30, uniformly and efficiently applied to all the surfaces of the sapphire specimen 30 after the heat treatment for coloring There is an advantage that coloration is easily performed.

Further, since only particles of the fine metal oxide powder having high purity are used, it is advantageous to provide a uniform and efficient coloring on all the surfaces of the sapphire sample 30.

≪ Heat treatment step (400) >

The crucible 10 in which a plurality of sapphire specimens 30 are placed is covered with a lid 20 and then put in a heat treatment furnace (not shown) and heat-treated.

The heat treatment consists of a cycle of temperature rise, temperature holding and temperature lowering, for example, the temperature holding may be performed at 800 to 1700 占 폚 for 1 to 20 hours.

Here, the heat treatment temperature is preferably 100 ° C or more higher than the melting point of the metal oxide powder, but may vary depending on the time and the heat treatment atmosphere.

The heat treatment is preferably carried out in an oxidizing atmosphere using an oxidation furnace which is inexpensive in manufacturing equipment and simple in manufacturing method. However, depending on working conditions such as the kind of the sapphire specimen 30 and the metal oxide powder 40 and the heat treatment conditions, Or in a vacuum atmosphere.

The sapphire specimen 30 is subjected to physical pressure by the vapor (gas) evaporated and filled in the closed space formed by the crucible 10 and the lid 20 during the heat treatment. As a result, the contact between the metal oxide powder 40 and the sapphire specimen 30 can be more reliably adhered by the pressure, thereby providing a uniform coloring.

In other words, since the crucible 10 is covered with the lid 20 during the heat treatment, the vapor of the metal oxide powder 40 that has been vaporized by the heat treatment is discharged into the crucible 10 through the solid diffusion The amount of the metal oxide powder 40 can be reduced as compared with the case where the cover 20 is not covered with the cover 20 because the cover 20 can not easily discharge the vapor out of the crucible 10, Can be lowered.

Here, the degree of sealing between the crucible 10 and the lid 20 is preferably a degree provided by the weight of the lid 10, but is not limited thereto.

On the other hand, in order to prevent the inner pressure of the crucible 10 from being increased too much by the vapor of the metal oxide powder 40 during the heat treatment, it is necessary to form a minute gap between the lid 20 and the crucible 10 have.

The steam ions evaporated by the metal oxide powder 40 are diffused into the sapphire specimen 30 by the heat treatment as described above and are colored with intrinsic colors by steam ions. For example, when heat treatment is performed using chromium oxide (CrO ₃ ), cobalt oxide (Co ₃ O ₄ ), or nickel oxide (NiO) as the metal oxide powder 40, the sapphire specimen 30 is colored green, Can be colored.

The coloring mechanism by the heat treatment is ion exchange by solid diffusion and the sapphire sample 30 is composed of single crystal alumina (Al ₂ O ₃ ), and Al ions are exited in the heat treatment process together with the metal oxide powder 40, Ions of Co, Ni, Cr, or Zn generated by evaporation of the metal oxide powder 40 are contained. In this case, the smaller the diameter of the ion, the better the ion exchange and the better the coloration.

In other words, ion exchange is performed by exchanging the metal ions of the metal oxide powder 40 and the metal ions of the sapphire specimen 30.

Here, the color of the metal oxide powder 40 may cause the weight of the sapphire specimen 30 to become heavy.

The depth of the sapphire specimen 30 to be colored is deepened as the solid diffusion due to the heat treatment is performed. Therefore, in order to deepen the color depth, the heat treatment time and temperature must be not less than the appropriate time and appropriate temperature, and sufficient metal oxide powder 40 You must provide them.

In addition, the color tone of the sapphire specimen 30 must have a color density higher than a certain level. In order to increase the color density as the solid diffusivity due to heat treatment increases under the same working conditions, And sufficient metal oxide powder 40 should be provided.

The depth to be colored may be about 10 탆 or more on the surface of the sapphire specimen 30 in consideration of a polishing process and the like provided later, but the concentration is not limited to this, and the concentration of the color tint may be a concentration higher than a certain level Lt; / RTI >

As described above, since the coloring is performed in the oxidizing atmosphere using the oxidation furnace during the heat treatment, the manufacturing process is easy and the manufacturing cost is low.

In addition, it is possible to minimize the contamination of the heat treatment furnace by applying the lid and to increase the coloring efficiency by increasing the pressure of the vapor of the metal oxide powder, and by providing uniform working conditions, uniform color and concentration There is an advantage that it can be provided reliably and economically.

≪ Surface treatment and polishing step (500) >

The sapphire specimen 30 colored by the heat treatment is taken out from the crucible 10 and polished so as to have a glossy surface to obtain a transparent sapphire specimen colored.

The surface of the sapphire specimen 30 colored by the heat treatment may appear to have a weak gloss or puffiness, which can be polished through polishing.

In order to improve the efficiency in polishing, the sapphire specimen 30 colored by heat treatment is immersed in nitric acid, sulfuric acid or hydrochloric acid having a concentration of about 40% to 60%, and then taken out to remove the residue formed on the surface of the sapphire specimen 30 And then the above polishing treatment may be performed.

The polished polishing may be performed using a paste mixed with a diamond powder or a brush. For example, chemical mechanical polishing such as CMP (chemical mechanical polishing), brush polishing or barrel polishing may be used.

As an example, the surface roughness Ra of the sapphire specimen 30 may be 0.5 nm by polished polishing.

In the present invention, a high-quality green sapphire specimen was prepared using chromium oxide (CrO ₃ ) powder having a purity of 90% or more as the metal oxide powder 40. However, the present invention is not limited to this, and various metal oxides and sapphire specimens having high purity can be reliably contacted in a limited space, and then heat-treated in an oxidizing atmosphere to color the specimen in various colors.

For example, high-quality blue transparent single crystal sapphire can be produced using cobalt oxide (Co ₃ O ₄ ) powder having a purity of 90% or more as a metal oxide powder.

If one metal oxide with high purity is used as the metal oxide powder for solid diffusion, it can be colored with the inherent color of the corresponding metal oxide. In contrast, in order to color with a desired color, another metal oxide powder A mixed metal oxide powder in which two or more kinds of intermetallic bonds are formed through the calcination process by uniformly mixing, drying and pulverizing the metal oxide powder may be used.

Here, the particle size of the mixed metal oxide powder may be 0.08 mm or less on the basis of D50, and the calcination process may be performed in an oxidizing atmosphere of 1000 deg. C or less, which is relatively low temperature, but is not limited thereto.

In this case, there is an advantage that the technique of providing the metal oxide powder 40 is difficult and the manufacturing process is complicated, but various colors can be provided.

Colorless transparent and colorless sapphire specimens can be used for a variety of applications. For example, it can be used in automobile emblems, stereograms, rings, necklaces, automobile pendants, cups, bowls, eyeglasses frames, watches or display screens of mobile communication devices, or to be used as a touch glass for fingerprint recognition buttons .

Also, an LED in which light is emitted through the sapphire specimen can be manufactured by forming the n-type nitride semiconductor layer and the p-type nitride semiconductor layer on the surface of the colored sapphire specimen and forming a light emitting layer therebetween.

As described above, since the coloring method of the present invention is very economical and reliable, it is easy to mass-produce and the manufacturing cost is reduced. In addition, the colored ceramic monocrystals are well worthy of being used for jewelry and industrial purposes because they are colored with a uniform color as a whole.

However, the present invention can be applied to a colorless transparent ceramic single crystal which is provided as a natural or artificial color uniformly and economically with a large amount of coloring And the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the present invention should not be construed as being limited to the embodiments described above, but should be construed in accordance with the following claims.

10: Crucible
20: Cover
30: The Psalms
40: metal oxide powder

Claims (25)

A method of coloring a single crystal transparent sapphire specimen of artificial color,
Placing a metal oxide powder on the bottom of the heat-resistant crucible;
Disposing a plurality of the sapphire specimens on the metal oxide powder at predetermined intervals;
Further comprising the step of inserting the metal oxide powder so that the plurality of arranged sapphire specimens are completely covered with a predetermined thickness;
Making the plurality of sapphire specimens uniformly contact the metal oxide powder; And
A step of covering the crucible with a heat-resistant lid, placing the crucible in a heat treatment furnace, and heat-treating the resultant to allow the metal oxide powder to color the sapphire specimen. The method according to claim 1,
Wherein the heat treatment is performed in an oxidizing atmosphere. The method according to claim 1,
Wherein the heat treatment is performed in a cycle of temperature rise, temperature holding and temperature lowering, and the temperature is maintained at 800 ° C to 1700 ° C for 1 hour to 20 hours. The method according to claim 1,
Wherein the diameter of the metal oxide powder is 0.06 mm or less on the basis of D50, and the purity of the metal oxide powder is 90% or more. The method according to claim 1,
Wherein the specimen is polished before the specimen of the sapphire is placed so that the surface is polished. The method according to claim 1,
Wherein the arrangement is transversal, and the entire outer surface is covered with the metal oxide powder. The method according to claim 1,
Wherein the step of disposing the metal oxide powder and the step of adding the metal oxide powder are repeated a predetermined number of times. The method according to claim 1,
Wherein the uniform contact is caused by vibration. The method according to claim 1,
The steam evaporated by the heat of the metal oxide powder during the heat treatment is filled in a part of the closed space formed by the lid and the crucible to increase the pressure so that the metal oxide powder is further subjected to a physical pressure Characterized in that the sapphire coloring method. The method of claim 9,
Wherein the lid covers the crucible so that the steam partially escapes during the heat treatment. The method according to claim 1,
Wherein steam ions evaporated from the metal oxide powder by the heat treatment are diffused into the specimen and colored with intrinsic color by the steam ion. The method according to claim 1,
Wherein the diffusion is a solid diffusion. The method according to claim 1,
Wherein the diffusion is performed by exchanging metal ions of the metal oxide and metal ions of the sapphire specimen. The method according to claim 1,
Wherein the specimen is colorless and transparent and the heat treatment is performed in an oxidizing atmosphere and the metal oxide is chromium oxide (CrO ₃ ), cobalt oxide (Co ₃ O ₄ ), or nickel oxide (NiO) having a purity of 90% Are colored in green, blue and sky blue, respectively. 15. The method of claim 14,
Wherein the mixed metal oxide powder has a particle size of 0.08 mm or less on a D50 basis. The method according to claim 1,
Wherein the metal oxide powder is a mixed metal oxide powder in which one metal oxide powder and another metal oxide powder are uniformly mixed, dried and pulverized, and then calcined to form two or more kinds of intermetallic bonds. Way. The method according to claim 1,
Wherein the colored specimen is surface-treated with a solution of any one of nitric acid, sulfuric acid or hydrochloric acid having a purity of 40% to 60% before polishing. The method according to claim 1,
And polishing the surface of the colored sapphire specimen so that the surface of the colored sapphire specimen is glossy. Preparing a specimen of sapphire by cutting and polishing a colorless transparent synthetic single crystal sapphire ingot to a predetermined size;
Placing the specimen in a heat-resistant crucible containing a metal oxide powder so that the specimen is completely covered with the metal oxide powder so that the metal oxide powder is uniformly in contact with the specimen as a whole;
Placing the heat-resistant crucible on a heat-resistant lid, placing the heat-resistant lid in a heat treatment furnace and performing heat treatment; And
And vaporizing the vaporized ions of the metal oxide powder by the heat treatment to diffuse into the specimen and coloring the vaporized ion by the steam ion. The method of claim 19,
Wherein the heat treatment is performed in an oxidizing atmosphere. The method of claim 19,
Wherein the lid covers the crucible so that the steam partially escapes during the heat treatment. The method of claim 19,
Wherein the diffusion is performed by exchanging metal ions of the specimen with metal ions of the metal oxide by solid diffusion. The method of claim 19,
Wherein the metal oxide powder is a mixed metal oxide powder in which one metal oxide powder and another metal oxide powder are uniformly mixed, dried and pulverized, and then calcined to form two or more kinds of intermetallic bonds. Way. The method of claim 19,
Further comprising the step of polishing the surface of the colored specimen so as to have a gloss. The transparent colored sapphire according to any one of claims 1 to 24, wherein the transparent colored sapphire is colored.

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