Precoated sand shell lost foam precise casting method

Abstract

The embodiment of the invention discloses a precoated sand shell lost foam precise casting method which comprises the steps: injecting raw materials and auxiliary materials into a mold cavity, expanding to form a model under the action of high temperature steam, after drying and design finalizing, string-carrying the model on a pouring system; putting the model in a precoated sand mold, controlling a heating solidification temperature, and solidifying; sending the precoated sand model into an oven or a drying furnace, and vaporizing foams, to obtain an empty shell; pouring liquid metal in the empty shell, and cooling to form a casting piece; after the casting piece is molded, forming and removing a sand shell at the outer surface of the casting piece so as to obtain a required completely-bare metal shape; and removing residual sand and oxidized skin on the surface of the casting piece. The precoated sand shell lost foam precise casting method adopts a method combining a lost foam forging method with a precoated sand shell forging method, has the advantages of good demolding performance and easy filling of corners of the casting piece through the precoated sand shell forging method, and allows a produced small precise complex casting piece to have an integral structure.

Description

technical field [0001] The invention relates to a lost foam casting method, in particular to a lost foam precision casting method of a coated sand shell. Background technique [0002] The traditional lost foam casting is also called negative pressure compaction casting. It mainly embeds the model made of foam into dry sand without adhesive for molding, and uses microseismic pressure to compact it. In the absence of sand core or even riser Liquid metal is poured under the condition of pouring and solidification, and a certain negative pressure is maintained during the pouring and solidification process to vaporize the foam plastic and then be replaced by metal to form a casting; it is characterized by one-time molding of the casting and high dimensional accuracy, which can greatly improve the environment of the foundry workshop condition. It is easy to realize pollution-free production, and the shape and structure of castings are not restricted, thus providing sufficient fre...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the embodiments of the present invention is to propose a lost foam precision casting method for coated sand shells in view of the problem that the corners of complex castings are difficult to fill when the current lost foam forging method produces small precision and complex castings

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