Technology and equipment for rapid growth of corundum sapphire crystal material by flame fusion method

Abstract

The invention relates to a process and a device for rapidly growing a sapphire crystal material of a corundum system by virtue of a flame fusion method and belongs to the field of processes and devices for preparing crystals of the corundum system by virtue of the flame fusion method. By improvement on the crystal growth process, the rapid growth method is effectively broken through, the difficulty of not large growth size of the crystal is completely solved, the production efficiency is greatly improved and the production cost is further effectively controlled. Furthermore, at a high temperature of 2050 DEG C, the low-melting-point impurity in gamma-Al2O3 powder is gasified, the high-melting-point impurity is oxidized under an oxidizing atmosphere, the growth process of the crystal is fully realized, the repurification and recrystallization processes of the crystal are completed in fact, therefore, under the new process condition, the purity of alpha-Al2O3 sapphire crystal reaches up to 99.9998% and the requirement of users on the purity of the crystal is fully met. The whole set of device has simple and reasonable structure and design, is scientific and practical and suitable for being popularized in the industry and the crystal growth operation is efficiently performed in high quality manner.

Description

technical field [0001] The invention belongs to the field of technology and equipment for producing corundum-based crystals by a flame-melting method, and in particular relates to a technology and equipment for rapidly growing corundum-based sapphire crystal materials by a flame-melting method. Background technique [0002] Corundum sapphire material (a-AL 2 o 3 )'s outstanding physical and chemical characteristics are: high temperature resistance, melting point as high as 2050 ° C, high hardness, Mohs hardness level 9, second only to diamond Mohs hardness level 10, density 3.98g / cm³, does not react with strong acids and alkalis, and GaN The lattice mismatch rate: 13.8%, the thermal expansion mismatch rate is small. Therefore, it is the most ideal substrate material for making epitaxial substrates for LEDs. In addition, GaN / / sapphire blue-light diode technology made a breakthrough in the 1990s and became mature, white light lighting emerged, and sapphire has new uses. Re...

AI Technical Summary

Problems solved by technology

However, in actual use, since the alumina powder required for crystal growth is very susceptible to moisture, once it encounters rainy weather or is produced in a humid area, or the production line is shut down for a period of time, it will lose the thermal baking effect brought by the combustion of the furnace body. , the alumina powder will absorb the moisture in the air and solidify into blocks, which will make it difficult for smooth feeding

[0006] Second, the gas supply device of the traditional crystal growth furnace is a simple main branch pipe structure. Since the distance between each branch pipe and the main pipe is far or near, the gas flow rate in the branch pipe closer to the main pipe is significantly higher than that in the far branch pipe. In addition, the gas source The gas delivery volume at the site is not constant, and the gas volume in the main pipe also fluctuates frequently, which eventually leads to unstable gas supply flow during the crystal growth process, and the crystal growth rate and quality will be seriously affected.

[0007] Third, in the traditional burner, because the powder, hydrogen and oxygen are simply charged into a combustion chamber for combustion, the uneven mixing of the materials leads to insufficient combustion, and it is difficult to ensure uniform texture of the final crystals. Uneven stress, poor quality

[0008] Fourth, the furnace body of the traditional growth furnace is generally designed to be cylindrical, with a large heat dissipation area, and there are defects such as poor thermal insulation performance, which will lead to low yield of crystal growth and obvious structural defects

The design of the traditional lifting system is relatively rough and simple, it is difficult to effectively fine-tune the growth position of each crystal on a group of production lines, and the equipment structure that can realize this function in imported equipment is too complicated, not only the purchase cost is high, but also it is not conducive to maintaining the stability of production operations. Stability and Maintenance Overhaul

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