Ceramic shell dewaxing method

Abstract

The invention discloses a ceramic shell dewaxing method. The method includes the steps that (1) before a ceramic shell with a wax mould enters a dewaxing procedure, a heat resisting layer which differs from thin to thick is disposed outside the ceramic shell with a dewaxing opening serving as the starting point; (2) the ceramic shell with the wax mould and the heat resisting layer are put in dewaxing equipment, the dewaxing opening in the ceramic shell faces downwards, the thinnest area of the heat resisting layer outside the ceramic shell is located in the undermost position in the vertical direction, and the thickest area of the heat resisting layer is located in the uppermost position in the vertical direction; and (3) after the ceramic shell with the wax mould and the heat resisting layer enters the dewaxing procedure, the heat resisting layer outside the ceramic shell controls the wax mould in the ceramic shell from bottom to top to gradually change and absorb dewaxing heat, the wax mould in the ceramic shell uses the dewaxing opening as the melting starting point, and sequential dewaxing is achieved from outside to inside and from bottom to top. By means of the ceramic shelldewaxing method, auxiliary dewaxing openings in the ceramic shell can be reduced or directly omitted, and the qualified rate and quality of dewaxing and forming of the ceramic shell can be guaranteedeffectively and reliably.

Description

technical field [0001] The invention relates to a ceramic shell forming technology for investment precision casting, in particular to a ceramic shell dewaxing method. Background technique [0002] Investment casting, also known as lost wax casting, uses wax to make a wax mold of the part to be cast, and then dips the wax mold with slurry and sand to make a ceramic shell, and then melts and removes the wax mold inside the ceramic shell. Get the cavity that matches the part to be cast, and finally pour the molten metal into the cavity of the ceramic shell under certain process conditions to cast the casting. Castings formed by investment precision casting have technical advantages such as high precision, good surface quality, and less post-processing, so they have been widely used, especially in the molding of alloy castings that are difficult to process such as superalloys. [0003] As mentioned above, the cavity of the ceramic shell is obtained by melting and removing the w...

AI Technical Summary

Problems solved by technology

There is little research on how to control the dewaxing sequence of the wax pattern in the ceramic shell. In the disclosed prior art, there is no such thing as reducing the auxiliary dewaxing port on the ceramic shell or canceling the auxiliary dewaxing by controlling the dewaxing sequence. At the same time, the technical research results of effectively ensuring the low crack rate of the ceramic shell during dewaxing were disclosed

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