Hardening agent for investment casting

Abstract

The invention relates to a hardening agent for investment casting. The hardening agent comprises, by weight part, 20-30 parts of aluminum polychlorid, 10-15 parts of crystallized magnesium chloride, 10-15 parts of ammonium chloride and 0.3-0.8 part of fatty alcohol-polyoxyethylene ether. The hardening agent is high in normal-temperature strength and high-temperature strength; the strength of a mold shell is guaranteed in the production process; losses of the mold shell are reduced; meanwhile, the retained strength of the mold shell is lowered; the problem that sand is difficult to clear is solved; and operation of the subsequent procedures can be conducted conveniently.

Description

technical field [0001] The present invention relates to a hardener, especially a hardener for investment casting. Background technique [0002] In investment casting, the hardener plays a key role in the performance of the shell-making process. The quality of the shell-making directly affects the dimensional accuracy and surface roughness of the casting, which in turn affects the production efficiency and production cost. At present, one of ammonium chloride, crystalline magnesium chloride, and crystalline aluminum chloride is commonly used to harden the mold shell alone. Among them, ammonium chloride has a smaller viscosity, faster penetration speed, higher production efficiency, lower residual strength, and easy detachment. Shell, but its shortcomings are also very obvious. First, it will produce a large amount of ammonia gas, which is very harmful to people and the environment. The content of NaCl and NaO2 in the hardening solution makes the process cumbersome; the cry...

AI Technical Summary

Problems solved by technology

[0002] In investment casting, the hardener plays a key role in the performance of the shell-making process. The quality of the shell-making directly affects the dimensional accuracy and surface roughness of the casting, which in turn affects the production efficiency and production cost.

At present, one of ammonium chloride, crystalline magnesium chloride, and crystalline aluminum chloride is commonly used to harden the mold shell alone. Among them, ammonium chloride has a smaller viscosity, faster penetration speed, higher production efficiency, lower residual strength, and easy detachment. Shell, but its shortcomings are also very obvious. First, it will produce a large amount of ammonia gas, which is very harmful to people and the environment. The content of NaCl and NaO2 in the hardening solution makes the process cumbersome; the crystalline magnesium chloride material is cheap, odorless and does not pollute the environment, which can fully improve the working conditions, but it is easy to lose water and deliquescence, so it needs to be stored in plastic containers and has certain viscosity. Moreover, the high-temperature strength and residual strength are low, which cannot fully meet the requirements of shell hardening; crystalline aluminum chloride has high high-temperature strength, good thermal stability and odorless, high residual strength, and difficult shelling. The viscosity of the hardening liquid is relatively high, and the hardening speed is too slow, resulting in low production efficiency and relatively expensive materials