SU1174151A1 - Solution for removing pattern material from shell moulds - Google Patents

Abstract

THE SOLUTION FOR REMOVAL OF A MODEL MATERIAL FROM THE ENVELOPE FORM, produced according to melted models, obtained from slurries with a liquid glass binder, including hardener and water, characterized in that with. in order to improve the quality of shell forms by increasing the strength of the shells after the models are melted, the solution contains triethanol-yangan as a hardener of the liquid glass binder in the following ratio of ingredients, wt.%:

Description

J1174

The invention relates to foundry, in particular, to casting on melted models to remove model material from ceramic shell molds.5

The aim of the invention is to improve the quality of shell forms by increasing the strength of the shells after the models are made of them.

In the proposed solution, O contains triethanolamine, which is a viscous transparent liquid from yellow to light brown in color with a weak ammonia smell, dissolves well in water, alcohol, acetone; 5, the chemical formula N (C2H40H) j. Like other mixed-function compounds, triethanolamine exhibits properties of both alcohols and amines.

In the process of melting the model material 20 in an aqueous solution of triethanolamine, the shell mold is cured with a liquid glass binder, the mechanism of which can be explained as follows. Under the action of 25 triethanolamine, the electrokinetic potential of liquid glass micelles decreases: {CsiOJJSiO i x2 (nx) Na 2 x Na, as a result of which negatively charged particles go over to the isoelectric state with complete loss of aggregative stability, particles of liquid glass ashes coagulate into a solid, dense gel.

512

Thus, during the melting of a model material from shell molds made with a liquid-glass binder, the colloidal liquid-glass system coagulates according to the following scheme: sol-ustuden and solidification of liquid glass. This tells the shell forms, after removing the model composition from them, high mechanical strength compared to limestone, where they use a solution for processing shell forms that contains,%: triethanolamine 10-30, 5% water emulsion of polymethylsiloxane 15-30 and water - the rest.

When the shell forms are calcined, triethanolamine is almost completely removed from the forms.

The properties of the four shell forms are investigated: the first two layers with ethyl silicate binder, the third and fourth layers with liquid glass binder without prior chemical treatment, melted in solutions (Table 1) of triethanolamine at 101 ° C for 10 minutes. The melting solution is prepared from triethanolamine at a technical density of 1.106 g / cm by combining and mixing with water until complete dissolution.

Table 1

Triethanolamine30. 40 Voda70, 60 Tensile strength of the form during static bending after melting from it of model material, kgf / cm 29 33

When the content of triethanolamine in the composition of the solution is less than 40%, a decrease in the strength of the shell

forms after melting from them the model composition. The increase in the solution content of triethanolamine more than 70% 60 70 80 40 30 20 35 39 39

does not improve the properties of the shell forms.

Comparison of the properties of samples of shells that have the first two layers with an ethyl silicate binder and the last two layers with a liquid glass, melt 10 15

90 85 70

15 21 25

The strength of the samples after calcination according to the proposed method is 1.5 times higher, which leads to a reduction in scrap casting according to clogging.

Thus, making shell forms from two layers with an ethyl silicate binder and two layers with a liquid glass binder in an aqueous solution of triethanolamine (triethanolamine 30-70% and the rest is water) at 1174741514

In the proposed (1-3) and known (4-6) solutions, it shows (Tables 1 and 2) that the strength properties of the proposed samples are 1.2–2 to 5 times higher than those of the known samples.

table 2

15

thirty

ten

30 25 15 60 60 55

15

17

13

leads to the curing of the liquid layers of the shell and increases the strength of the shell before and after calcination, which reduces scrap-casting by clogging.

 The use of the proposed solution will ensure the strength of the shell forms after melting of the model composition from them by more than 1.5 times, and the reduction in the marriage of castings in clogging.

Claims (1)

SOLUTION FOR REMOVING THE MODEL MATERIAL FROM CASING FORMS, manufactured by investment casting, obtained from suspensions with a liquid-glass binder, including hardener and water, characterized in that, in order to improve the quality of shell molds by increasing the strength of the shell after melting models from them, in as a hardener of a liquid-glass binder, the solution contains triethanolamine in the following ratio of ingredients, May.%: Triethane Olamine Water