Hardening agent for investment casting of mold shells

Abstract

The invention relates to a hardening agent for investment casting of mold shells. The hardening agent comprises the following components in parts by weight: 30-50 parts of crystallized magnesium chloride, 15-25 parts of ammonium chloride, and 0.3-0.6 part of fatty alcohol-polyoxyethylene ether. The hardening agent is high in permeation hardening capacity and higher in normal-temperature strength and high-temperature strength, guarantees the strength of the mold shells in the production process, reduces the loss of shell types, meanwhile, reduces the residual strength of the mold types, solvesthe sand removal difficulty, facilitates operation of subsequent procedures, improves the production yield, reduces the labor intensity of workers, and is simple in process and free of environmental pollution.

Description

technical field [0001] The invention relates to a hardening agent, especially a hardening agent for investment casting medium shells. Background technique [0002] In investment casting, shell making is a crucial process in investment casting. The quality of the shell directly affects the dimensional accuracy and surface roughness of the casting, which in turn affects the production efficiency and production cost. In the shell making process , the hardener plays a key role in the strength and performance of the shell. [0003] At present, in the prior art, one of ammonium chloride, crystalline magnesium chloride, and crystalline aluminum chloride is mostly used to harden the shell alone. Among them, ammonium chloride has a smaller viscosity, faster penetration speed, higher production efficiency, and residual It has low strength and is easy to shell, but its disadvantages are also very obvious. First, it will produce a large amount of ammonia gas, which is very harmful to...

AI Technical Summary

Problems solved by technology

[0003] At present, in the prior art, one of ammonium chloride, crystalline magnesium chloride, and crystalline aluminum chloride is mostly used to harden the shell alone. Among them, ammonium chloride has a smaller viscosity, faster penetration speed, higher production efficiency, and residual It has low strength and is easy to shell, but its disadvantages are also very obvious. First, it will produce a large amount of ammonia gas, which is very harmful to people and the environment, and the working conditions are harsh. The loss is large, and the content of NaCl and NaO2 in the hardening solution needs to be regularly measured, resulting in cumbersome procedures; crystalline magnesium chloride is cheap, odorless and does not pollute the environment, which can fully improve working conditions, but it is easy to deliquescence and needs to be stored in plastic containers. Certain viscosity, and low high temperature strength and residual strength, can not fully meet the requirements of shell hardening; crystalline aluminum chloride has high high temperature strength, good thermal stability and odorless, and its residual strength is also high, Shelling is difficult, and at the same time, the viscosity of the hardening solution is relatively high, and the hardening speed is too slow, resulting in low production efficiency and expensive materials