SU1503970A1 - Sand for manufacturing water soluble cores - Google Patents

Abstract

The invention relates to a foundry, namely, mixture compositions for the manufacture of water-soluble casting cores of complex configuration and length for casting from light alloys. The purpose of the invention is to improve the quality of the rods by increasing the fluidity of the mixture, as well as reducing the time to remove the rods from the castings, due to the additional addition of calcium hydrochloride to the composition at the following ratios of ingredients, wt.%: Silica hydrosol 20-23

calcium hydrochloride 4.3-5.8

sodium chloride else. The combined content of silica and calcium hydrochloride in the mixture of hydrosol provides the mixture with high flowability, which allows the manufacture of rods of complex configuration and length. In this case, the rods have good solubility in hot water. 1 tab.

Description

The invention relates to a foundry, in particular, to mixture compositions for the manufacture of water-soluble casting cores for castings from light alloys.

The purpose of the invention is to improve the quality of the rods by increasing the flowability of the mixture, as well as reducing the time to remove the rods from the castings.

The mixture contains ingredients in the following ratio, wt.%: Silica hydrosol 20-23 Calcium hydrochloride 4.3-5.8 Sodium chloride Else In the core mixture, silica hydrosol, stabilized by alkali, is used as the liquid phase.

and calcium chloride is a plasticizer. As a result of the interaction of silica hydrosol with pvdrochloride, calcium sol coagulates and becomes gel. The mixing of fine sodium chloride with the resulting mass leads to the formation of a gel shell on the salt particles, as a result of which the friction between particles in the process of pressing the core mixture decreases and the flowability increases accordingly. The liquid phase does not separate because it is in a bound state .

To prepare the core mixture, silica hydrosols are mixed with calcium hydrochloride until a uniform consistency is obtained.

SP

about 00

from 41

31503970

Tanas, which are pressed into the core box. Curing of the mixture occurs during the drying process.

Examples of the core mixture and its properties are shown in the table.

The flowability of the rod mixture was determined by the length of filling the precast cylinder with a channel diameter of 10, 5, 4, 2 mm and a length of 50 mm. The determination of the tensile strength during static bending was performed by testing cylindrical rod samples with a diameter of 10 mm and a length of 50 mm. The removal time was determined by dissolving embedded core samples with a diameter of 10 mm and a length of 50 mm in hot running water.

The implementation of the invention will allow the manufacture of rods from a water-soluble mixture, having a complex configuration and a long length, for casting from light alloys during casting

chill mold, since such a mixture has high fluidity, sufficient strength and. good solubility in water.

Claims (1)

Invention Formula The mixture for the manufacture of water-soluble rods of predominantly long length, complex configuration, including fine sodium chloride and silica hydrosol, characterized in that, in order to improve the quality of the rods by increasing the flowability of the mixture, as well as reducing the time to remove the rods from the castings, Calcium hydrochloride in the following ratio of ingredients, wt.%: Silica hydrosol 20-23 Calcium hydrochloride 4.3-5.8 Sodium chloride Else nineteen 20 21 22 23 We offer a mixture of 3.8 128 4.3 4.8 5.3 5.8 142 156 170 184 69.7 24 6.3 Prototype 80 20 s 7,8 8.0 8.5 8.9 9.3 9.6 Strength is insufficient  Difficult rod removal Sharp increase in adhesion, the rod is not removed 143 12.0