Preparation method of blue mullite

A moissanite and blue technology, applied in the field of moissanite preparation, can solve the problems of light color of moissanite, uncontrollable release speed of doping substances, poor uniformity of moissanite crystal color, etc., and achieve simple and controllable operation Effect

Inactive Publication Date: 2020-08-25
NANTONG UNIVERSITY
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Problems solved by technology

However, this method for preparing colored moissanite cannot control the release rate of doping substances, so the color uniformity of the obtained moissanite crystals is poor. In the early stage of growth, more doping substances are released, so the color near the seed crystal area is relatively poor. Deep, in the later stage of growth, the doping substances are almost released and there is little left, and the color of moissanite is very light

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  • Preparation method of blue mullite
  • Preparation method of blue mullite

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preparation example Construction

[0026] In order to solve the above technical problems, the technical solution adopted in the present invention is: Figure 1-2 Shown, a kind of preparation method of blue Moissanite comprises the following steps:

[0027] Step (1), high-purity silicon carbide powder 6 is mixed evenly with doped metal aluminum or aluminum-containing compound, put into high-purity graphite crucible 2, moissanite polycrystal is fixed on the inner side of graphite crucible cover as seed crystal 1, and graphite is sealed The crucible is put into the crystal growth furnace and grown by physical vapor transport method.

[0028] According to a specific embodiment of the present invention, the purity of the silicon carbide powder is not less than 99.99%. According to some specific embodiments of the present invention, the doped metal aluminum or aluminum-containing compound is one or more of simple metal aluminum, aluminum nitride or aluminum phosphide. According to some specific embodiments of the p...

specific Embodiment 1

[0034] A method for preparing blue moissanite according to the present invention realizes the preparation of blue moissanite by doping metallic aluminum or aluminum-containing compounds, and controls the uniformity of doping metallic aluminum by a secondary crystallization method combined with an inner crucible device And then get blue moissanite with uniform color. Concrete preparation steps are:

[0035] Step (1), high-purity silicon carbide powder and doped metal aluminum nitride are evenly mixed, put into a high-purity graphite crucible, moissanite polycrystal is fixed on the inner side of the graphite crucible cover as a seed crystal, the graphite crucible is sealed, and the crystal is placed In the growth furnace, the physical vapor transport method is used for growth; the uniform mixing method is a ball milling method; the seed crystal fixing method is bonding and fixing.

[0036] Step (2), after cooling down, take out the aluminum-doped moissanite polycrystal, pulveri...

specific Embodiment 2

[0041]The difference from specific example 1 is that in the step (1), the aluminum-containing compound is metal elemental aluminum; the seed crystal is fixed by mechanical fixation; in the step (2), the cooling speed 50°C per hour; the micropore size of the graphite inner crucible cover is 50 microns. In the step (3), the material of the single crystal moissanite is 6H-type moissanite.

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Abstract

The invention discloses a preparation method of blue mullite. The preparation of the blue mullite is realized by doping metallic aluminum or an aluminum-containing compound; a secondary crystallization method is combined with an inner crucible device to control the uniformity of the doped metallic aluminum so as to obtain blue mullite with uniform color. The preparation method comprises the following steps of: firstly, fully mixing high-purity silicon carbide powder with doped metallic aluminum or aluminum-containing compound; selecting polycrystalline mullite as a seed crystal in a crystal growth furnace to grow doped polycrystalline mullite by a physical vapor transport method; taking out the polycrystalline mullite, breaking and putting the polycrystalline mullite into an inner crucible; putting high-purity silicon carbide powder into the bottom of an outer crucible; selecting monocrystal mullite as a seed crystal to be subjected to physical vapor transport growth again, so as to obtain blue mullite with uniform color. The aluminum and silicon carbide powder are combined in the first growth, the aluminum is slowly released along with the gasification of the silicon carbide in the second growth process, and therefore, the aluminum uniformly enters the mullite, and color uniformity control is achieved.

Description

technical field [0001] The invention relates to a method for preparing moissanite, in particular to a method for preparing blue moissanite. Background technique [0002] Moissanite, also known as silicon carbide gem, also known as moissanite, has been discovered for more than 100 years. Natural moissanite was first discovered in 1905. Moissanite is an inorganic compound, its chemical formula is SiC, and it is composed of silicon-carbon tetrahedrons. It has strong covalency. It has the characteristics of high melting point and high hardness. Its hardness is equivalent to that of diamonds, and it is resistant to corrosion and radiation. . Because of the high melting point, the thermal stability is very good, and the general temperature will not destroy the crystal structure of moissanite. [0003] Diamond is a well-known precious jewelry, which has a charming appearance, but natural diamonds are scarce, so they can be expensive. Artificial diamonds cannot be produced in larg...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/36C30B23/00
CPCC30B23/00C30B29/36
Inventor 杨培培李祥彪
Owner NANTONG UNIVERSITY
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