A kind of thermal insulation upper screen of sapphire growth kneading furnace

Abstract

The invention discloses an upper insulating screen for a sapphire growth kyropoulos furnace. The upper insulating screen is arranged between a furnace cover and a material melting liquid level in the kyropoulos furnace. The upper screen is provided with a central observing hole. A through observing groove is vertically arranged along an inclined angle on the upper screen. According to improvement of the observing groove, temperature distribution and gradient in a crystal growth area in the furnace are not largely affected, and crystal growth is not affected. The opening angle of the inclined observing groove can be adjusted according to the observing liquid level, diameter / height of the central hole and the position of the observing window of the furnace cover, so that the observing range is larger, and no observing dead angle is available, therefore, the head of the seed crystals can be observed completely in the seed crystal rotating process and solid-liquid level during seeding can be conveniently observed. Volatile matters are prevented from being gathered to block the observing opening by gradual retractive opening manner from bottom to top.

Description

technical field [0001] The invention relates to a new type of sapphire growth kneading furnace, in particular to a thermal insulation upper screen of the sapphire growth kneading furnace. Background technique [0002] In 1926, Kyropouls invented the Kyropoulos method. The principle of the Kyropoulos method is: put the raw material into a high-temperature-resistant crucible to heat and melt, adjust the temperature field in the furnace to make the temperature of the upper part of the melt slightly higher than the melting point; make the seed crystal on the seed rod contact the liquid surface, and wait until the surface is slightly After melting, reduce the surface temperature to the melting point, pull and rotate the seed rod, so that the top of the melt is supercooled and crystallized. During and after the crystal growth process, the crystal is not in contact with the crucible wall, thereby reducing crystal stress. [0003] Its principle is similar to the pulling method, bu...

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Problems solved by technology

[0015] 1. Straight observation slot 2': The observation range is small. When the seed crystal is rotated to the position close to the observation hole, there is a dead angle for observation, and the bottom of the seed crystal cannot be seen, which is not conducive to seeding and observation of the growth interface;

[0016] 2. There are a lot of volatiles in the process of crystal growth, and these volatiles will accumulate on the molybdenum sheet of the upper screen, and in severe cases, it will block the observation channel

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