SU1044652A1 - Modifier for aluminium-silicon alloys - Google Patents

Abstract

MODIFICATOR FOR ALUMINUM AND SILICON ALLOYS, including sodium fluoride, sodium cryolite, strontium chloride and sodium chloride, characterized in that, in order to increase the mechanical properties of the alloy, it contains these components in the following ratio, wt. %: -. Sodium fluoride10-15 Sodium cryolite2 5-3О Strontium chloride15-25 Sodium chlorideOstal

Description

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ND "The invention relates to metallurgists of non-ferrous alloys, in particular to the treatment of aluminum-silicon foundry alloys. The modifier C1 3 is known, containing the following components, May. %: Sodium chloride25-5 sodium cryolite7-15 ferrophosphor2O-3 (sodium fluoride3-7 potassium chloride remaining, however, the addition of ferrophosphorus leads to the formation of a coarse polyhedral structure, a decrease in plasticity and the appearance of heterogeneity in microporosity in castings. Also, the modifier L 3 for aluminum-to-homogeneity in microporosity in castings is known. alloys, including hexachloroethane and metallic strontium in the following ratio of components, May, 7 °: Hexochloroethane 10-25. .StrontiumOther The specified modifier allows to increase the time. and melt up to 1-2 hours while simultaneously reducing the time of melt processing with a m6difIcator up to 1–15 minutes, melt processing is performed in a ladle with a bell when the latter is immersed in the melt. However, the melt is treated with a modifier in the ladle for .10- 15 minutes leads to a significant loss of the temperature of the melt, which negatively affects the fluidity of the metal and the grain length in the castings, which results in a deterioration of the mechanical properties of the castings. In addition, strontium metal, which belongs to the group of alkaline-earth metals active in air, requires the creation of special devices and devices for its storage and use. The closest to the proposed technical essence and the achieved result is flux 3} for modifying, and refining alloys of aluminum with silicon, containing

Sodium fluoride 10-20

Haoristy. sodium5-15

Sodium cryolite10-15

Strontium chloride 2O-40

Potassium Chlorine Else

However, the known flux for single-day 1 refining of contaminated impurities and oxides of aluminum alloys is not sufficiently effective. Swelling of potassium chloride and lower

The manufacture of the modifier is reduced to the mixing of the components of the mixture and the subsequent mixture.

The use of the modifier during melting is carried out as follows.

For the melt for 20-30 minutes until the metal is downloaded from the furnace, a modifier in the amount of 0.2-0%, 9% is applied, after which the metal is mixed. The resulting slag from the furnace 52, the content of cryolite lowers the melting point of the flux, significantly increases its liquid mobility and impairs the protective properties. Oxygen and metal oxide diffuse easily through a layer of such flux. In addition, cryolite 7 does not provide the conditions for the reduction of alumina. All this does not provide aluminum alloy with silicon with high mechanical properties. The purpose of the invention is to improve the mechanical properties of the alloy. j The goal has been achieved by the fact that the modifier for aluminum alloys: with silicon, including sodium fluoride, sodium cryolite, strain chloride and sodium chloride, contains these components in the following ratio, wt. %: Sodium fluoride 10-15 Sodium cryolite25-30 Strontium chloride15-25 Sodium chloride Ostalal} Chloride striae used in the composition of the modifier, has a low melting point, high wetting ability, is passive in relation to aluminum and alloying components. It creates a protective film on the surface of the melt and prevents the penetration of air oxygen and hydrogen into the melt, is a modifier for aluminum alloys. Sodium fluoride has the ability to dissolve and adsorb oxides and remove gases. Sodium fluoride and cryolite make the film more dense and impermeable, wet aluminum oxide well and facilitate its removal. The use of strontium chloride is justified by the fact that this salt also produces a refining effect, simultaneously modifying the melt and allowing a relatively long time (more than 2 hours) to retain the effect of modifying the melt.

310446524

just before the metal is in the ladle. In the table, sgga are presented. However, it is possible to use modifiers and comparative

boats in the process of the entire melting in the coli-mechanical characteristics of the 0.2-O fuse, 4% with additional sources, expanding, 1x using triple phgaos in the amount: - 5th of the proposed and well-known

we 0,3-0,5% in the initial period of melting. 1difiers

15 10 5025

20 12.5 4О27,5

25 15 3030

30 15 1O12

(with known modifier)

Experimental testing was carried out on the most common alloy of ALZ.

Melting is carried out in a reflective furnace with treatment with a liquid melt modifier for 15 minutes.

For comparison, take the alloy ALS, smelted with processing according to known technology using known

modifier.

As can be seen from the table, the treatment of the melt with the proposed modifier can significantly increase the strength, hardness and ductility of the alloys in comparison with the known.

Mechanical characteristics were obtained on samples without heat treatment.

1.6 / 1.364.0 / 62.2

2.4 / 2.069.0 / 68.4

2.0 / 1.861.6 / 61.6

1.4 / 1, O58.8 / 58.6

The highest indicators are in terms of mechanics (alloy 2

From the data of the table it is also seen that the mechanical parameters of the samples with the proposed modifier change insignificantly after 1 and 3 hours, which proves the long-term preservation of the modification effect

The application of the proposed modifier allows you to grind the structure, increase the mechanical properties of the alloys, and also increase the melt modification time to. 2 hours

An increase in the modifying time has a positive effect when using distributing furnaces, in which the smelted metal is kept before the mold is cast for 1.5-2 hours.

Claims (3)

MODIFIER FOR ALUMINUM ALLOYS WITH SILICON, including sodium fluoride, sodium cryolite, strontium chloride and sodium chloride, characterized in that, in order to increase the mechanical properties of the alloy, it contains these components in the following ratio, weight. Sodium Fluoride 10-15 Sodium cryolite 25-30 Strontium Chloride 15-25 Sodium Chloride SP yo> t%: 25-35 7-15 20-30 3-7 · Else ί