Middle sealing sand filling technology capable of preventing inner leakage of investment casting

Abstract

The invention relates to a middle sealing sand filling technology capable of preventing inner leakage of investment casting. The technology specially comprises the following steps that silica solutionand zircon powder coating is adopted for a face layer of a wax module, and 120-mesh zircon sand is spread; 2, silica solution and zircon powder coating is adopted for a second layer, and 30-60-mesh mullite sand is spread; 3, silica solution and mullite powder coating is adopted for a third layer, and 30-60-mesh mullite sand is spread, 4, silica solution and mullite powder coating is adopted for afourth layer, only hanging coating is adopted for coating, no sand is spread, a hole is filled with sand after drying, and a hole opening is sealed; and 5, silica solution and zircon powder coating is adopted for follow-up layers, 16-30-mesh mullite sand is spread till requirements are met, and no sand is spread in the last layer. According to the middle sealing sand filling technology, the strength of a deep blind hole and a narrow deep groove of a mold shell can be improved, inner leakage at the positions can be effectively prevented, the inner leakage rate of small holes is reduced from the original 10% to 2% or below after adopting the method through tests, and the effect is obvious.

Description

technical field [0001] The invention relates to a middle seal sand filling process, in particular to a middle seal sand filling process for preventing internal leakage of investment casting. Background technique [0002] The investment casting production process mainly includes three processes: mold making, shell making and mold shell roasting and pouring. The shell making process is the wax mold group that completes the mold making process. It goes through multiple cycles of coating, sanding, hardening, and air drying. The process forms a coating module, and then melts and loses the wax to form a mold shell. [0003] In the production of investment casting, for the deep blind holes and narrow deep grooves of castings, it is not easy to coat the molding sand, resulting in holes, resulting in insufficient shell strength at the bottom of blind holes and grooves, and prone to internal leakage defects, resulting in blind holes, grooves There is more meat in the tank, resulting ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a middle seal sand filling process to prevent internal leakage of investment casting, which is used to solve the problem of low strength of deep blind holes and narrow grooves in the mold shell, and prevent internal leakage during pouring