A Shell Manufacturing Method for Precision Castings with Narrow Slot Structure

Abstract

The invention discloses a shell-making method for precision castings with a narrow slit structure, which comprises the following steps: 1) preparing surface layer slurry, when the inner hole size of each wax mold is smaller than a preset value, coating the surface layer slurry Cover the inner holes of each wax model to seal the inner holes of each wax model, and then combine the wax models to obtain a wax model module; when the size of the inner hole of each wax model is greater than or equal to the preset value, Combine the wax patterns to obtain the wax pattern module to be processed, and then apply the surface layer and the second layer of slurry to the wax pattern pattern to be processed. After the surface layer and the second layer of slurry are coated, then Prepare the reinforcement layer slurry, and then apply the reinforcement slurry to each inner hole in the wax pattern module to be processed, so that the inner holes in the wax pattern module are sealed to obtain the wax mold shell; 2) according to the The mold group completes the shell making of precision castings with narrow gap structures. The invention can effectively seal the inner hole in the wax mold module, and avoid the phenomenon of burrs or iron beans in the casting after the impact of the high-temperature molten metal.

Description

technical field [0001] The invention belongs to the technical field of investment precision casting production, and relates to a method for making shells of precision castings with narrow gap structures. Background technique [0002] In the production process of precision castings, the quality of the shell directly affects the quality of the castings. The burrs of the castings are removed by grinding and shot blasting in the post-processing process, which is labor-intensive and time-consuming, and affects the surface quality and dimensional accuracy of the castings. Burrs generally occur on the surface of castings, which are continuous or intermittent irregular protrusions, forming burrs and flashes. If burrs appear in grooves, narrow gaps or small inner cavity sizes, it is difficult to polish and cause castings to be scrapped. [0003] For investment castings with small inner holes or inner cavities, when this part is painted according to the normal wax pattern, it will be ...

AI Technical Summary

Problems solved by technology

[0002] In the production process of precision castings, the quality of the shell directly affects the quality of the castings. The burrs of the castings are eliminated by grinding and shot blasting in the post-processing process, which is labor-intensive and time-consuming, and affects the surface quality and dimensional accuracy of the castings.

Burrs generally occur on the surface of castings, which are continuous or intermittent irregular protrusions, forming burrs and flashes. If burrs appear in grooves, narrow gaps or small inner cavity sizes, it is difficult to polish and cause castings to be scrapped

[0003] For investment castings with small inner holes or inner cavities, when this part is painted according to the normal wax pattern, it will be blocked after two or three layers. The mold shell is thin and the density is poor. After being impacted by the high-temperature molten metal, burrs or iron beans appear on this part of the casting, which causes a large amount of grinding and difficult grinding in the subsequent process. The burrs and iron beans that cannot be removed will cause the casting to be scrapped, seriously affecting its qualification rate