Precision casting method for pouring evanescent mold through high-performance coating foam and mold laminating paraffin

Abstract

The invention discloses a precision casting method for pouring an evanescent mold through high-performance coating foam and mold laminating paraffin. The method includes the following steps: manufacturing an expandable polystyrene (EPS) foam mold; covering a paraffin mask on the foam mold; preparing high-performance coating; coating and drying the coating; filling sands for shaping; and burning out the foam and the paraffin mask in a casting mold and pouring metal liquid. The high-performance coating is prepared by mixing Guilin No.5 additive special for evanescent mold coating, 180-220 meshes of refractory aggregate powder and water with stirring and adding silicon solution into the mixture with stirring. Dimension accuracy and surface smoothness of a cast member poured by the method can achieve the level equivalent to that of investment precision casting small members, the shortcomings of carbon adding, slag inclusion, pores, wrinkled skin, carbon black, uneven composition, deviation of mechanical property and the like of the casting member do not exist, and large casting members, small casting members and medium casting members all can be manufactured.

Description

technical field [0001] The invention relates to lost-foam casting, in particular to a method for casting precision castings with high-performance coatings on lost-foam patterns coated with paraffin. Background technique [0002] The castings produced by traditional (existing) investment casting precision casting have high dimensional accuracy and high surface finish, but the manufacturing cost of the paraffin pattern is also quite high, and the operation is cumbersome (the density is about 60 times that of foam), and its mold making and coating preparation The processes of coating, shell dewaxing and recycling are quite complicated, especially after shell dewaxing, it must be baked in a kiln at a temperature of about 1000°C for more than 30 minutes before being boxed and poured, which consumes a lot of energy and the working conditions are harsh. , the pollution is serious, so the traditional (existing) investment casting is famous in the international casting industry for i...

AI Technical Summary

Problems solved by technology

[0002] The castings produced by traditional (existing) investment casting precision casting have high dimensional accuracy and high surface finish, but the manufacturing cost of the paraffin pattern is also quite high, and the operation is cumbersome (the density is about 60 times that of foam), and its mold making and coating preparation The processes of coating, shell dewaxing and recycling are quite complicated, especially after shell dewaxing, it must be baked in a kiln at a temperature of about 1000°C for more than 30 minutes before being boxed and poured, which consumes a lot of energy and the working conditions are harsh. , the pollution is serious, so the traditional (existing) investment casting is famous in the international casting industry for its "low cost" and can only cast small castings, usually weighing less than 50kg

Although the EPS foam pattern used in traditional (existing routine) lost foam casting is low in cost, light in operation, simple in mold making, easy to mix with paint, and simplified in process, the surface finish and dimensional accuracy of the foam pattern itself or its castings are inferior to those of Investment casting difference 1~2 grades

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