Silica crucible and method for fabricating the same

Abstract

The invention provides a silica crucible with a coating with a strong adhesion and method for fabricating the same. The silica crucible includes a vitreous silica body having an inner surface and an outer surface, the inner surface of the vitreous silica body defining a cavity adapted for containing a molten material or a powder material; and a first coating layer formed on the inner surface of the vitreous silica body. The first coating layer is formed by pyrolising a composite of aluminum, magnesium, calcium, titanium, zirconium, radium, chromium, selenium, barium, yttrium, cerium, hafnium, tantalum, tin or silicon under a predetermined temperature. The first coating layer is substantially consisted of a nonhomogeneous material, and an interface is defined by the homogeneous material and the nonhomogeneous material between the vitreous silica body and the coating layer. The first coating layer has strong adhesion capability and guarantees the coating layer will not be easily peeled off or removed through hand touching, raw materials loading into the silica crucible or vigorous transportation.

Description

technical field [0001] The present invention relates to a quartz crucible capable of withstanding high temperatures and avoiding physical or chemical reactions with materials placed therein for melting, transformation or decomposition, in particular to a coated quartz crucible and its manufacture method, the coating has strong adhesion. Background technique [0002] Quartz crucibles are widely used to contain materials that need to be transformed at high temperatures, such as melting or decomposition. Quartz crucibles are designed for high temperature resistance, adequate mechanical and thermal properties. The most important thing is to prevent the inner surface of the quartz crucible from physical or chemical reaction with the material contained in it, and avoid the production of certain impurities. [0003] A typical application of quartz crucibles is for the fine preparation of precious metals or alloys, such as the preparation of superalloys. In order to avoid certain...

AI Technical Summary

Problems solved by technology

[0007] However, the adhesion of the barium hydroxide or barium carbonate coating disclosed in U.S. Patent No. US5,980,629 is too small, and it is easy to peel off under the action of external force, for example, it is shaken off during the transportation process of violent shaking

Moreover, the coating is also easily scratched by fingers or by the material contained in the crucible, for example, by polysilicon raw material being loaded into the crucible prior to the pulling process.

These phenomena all appeared in the crucible with barium hydroxide or barium carbonate coating formed by the coating method provided by the above-mentioned patent

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