SU922169A1 - Modifier for hypoeutectic aluminium and silicon alloys - Google Patents

Description

I

The invention relates to foundry, in particular, to the production of modified aluminum-silicon alloys containing less than 13 wt.% Silicon.

In modern foundry, aluminum-silicon alloys are modified primarily in smelting and dispensing furnaces before being cast into molds.

Known modifiers for hypoeutectic aluminum alloys containing hexo; chloroethane and strontium 1 or hexachloroethane and antimony 21.

However, antimony and strontium-based modifiers are so weakly effective that they do not crush zv1 (chemical silicon in thick-walled molds castings and in all castings obtained in sand molds.

Closest to the invention in its technical essence and its positive effect is a modifier containing metallic sodium 3.

However, when metal sodium is used as a modifier of aluminum-silicon alloys, the effect of modifying cd alloys is maintained for 25-35 minutes after the introduction of sodium, which necessitates a re-modifying operation if the duration: casting the metal exceeds a specified time. The retention time of the modifying effect on the melt decreases with an increase in its temperature after the modifying operation; which significantly reduces the flexibility of the production of foundries. The duration of the modifying effect is quickly reduced by mixing the modified melt.

After the remelting of the already sealed metal, modified with sodium, the effect of modification completely disappears.

The aim of the invention is to improve the mechanical properties of the alloys and increase the effect of the Modification effect.

The target is achieved by the fact that in the modifier for hypoeutectic and eutectic aluminum fluxes containing sodium, lead is additionally introduced with the following solution components, wt%: Sodium4.5-20. Lead. Others The use of a modifier in the form of a lead-sodium alloy makes it possible to modify aluminum alloys with simpler, more economical and technologically advanced methods; holding the aluminum-silicon alloy rake in the furnace (in a tigde, etc.) on the liquid modifier layer; . or kapelsh (m overflow of a liquid modifier through the thickness of a liquid aluminum-silicon-alloy ;, a stream-like transfusion of an aluminum-silicon alloy lio to a liquid modifier; an extractable liquid modifier inside the melt of an aluminum-silicon alloy, etc.). All these technological methods are based on a lower melting temperature ( 380 °) and a higher density (78.0 g / cm) of the modifier than that of the aluminum-silicon-silicon alloy. These techniques, in particular, make it possible to simply solve the problem of continuous modification of aluminum-silicon-silicon The advantages of the lead-sodium modifier as a modifier are that it eliminates the phenomenon of re-modifying the cast structure, and the subsequent refining caused by the modification of the liquid aluminum-silicon alloy is not affected by subsequent refinement, but also by the refinement of the liquid aluminum-silicon alloy, resulting from the modification of the liquid aluminum-silicon alloy, did not affect the refinement of the structure of castings. re-melting together with ligatures and without ligatures. This, in particular, makes it possible to carry out an operation- modifying aluminum-silicon alloys from many The foundry subdivisions of machine building plants for silumin-producing metallurgical plants, which will supply ingots of modified silumin to the machine-building plants, which is the basis for the preparation of all aluminum-silicon alloys, which improves the sanitary-hygienic conditions of the cast-iron production and reduces its cost. The table shows the comparative data of the mechanical properties of unmodified and modified sodium and lead alloy sodium alloys AL2 (chemical composition AL2, wt.%: Si 10.52-10.46; Fe 1.08-1.18; Ck 0.07-0.08; Cu 0.03; Zn 0.11-0.17.

Unmodified17.4

Modified League 23.5

lead lead sodium

Modified22.1

sodium Comparative analysis shows that lead-sodium ligature, as a modifier, is more effective than sodium. Use of a ligature of lead sodium as a modifier of pre- and eutectic aluminum -. evo-silicon alloys instead of the known modes {| fixers poeto ols improve the quality of the cast, wok by reducing their gases and non-metallic inclusions, while simultaneously increasing the strength and ductility of the cast structure; eliminate the frequent repetition of the operations of modifying your melt, thereby directly increasing the labor productivity of the casting units and saving their working time; eliminate scrap castings for re-modifying and non-modifying the structure; solve the problem of continuous modrova3, 0 7.6

6.4 mi melts in closed automatic and semi-automatic metering furnaces, now and in the future so relevant not only for large-scale and mass production, but also for small-scale production of castings; increase the technological flexibility of the foundry; yield of metal, since the high effect of modifying the liquid alloy caused by the lead-sodium ligature is not adversely affected by subsequent technological operations such as refining, overheating, mixing of melts and joint re-melting with a ligature and without a ligature. Formulas for the invention of a modifier for hypoeutectic and eutectic aluminum-silicon alloys.

59221694

containing sodium, different sources of information,

By the fact that, in order to increase the mechanical values taken into account during the examination

alloy properties and increase long-1. USSR Copyright Certificate № 367167,

these effects of modification, in it add. C 22 C 21/04, 1971.

The pig was inferred with the following corre- sponce $ 2. USSR author's certificate N 376472, scientific research institute of components, wt.%: class. C 22 C 21/04, 1973.

Sodium4,5-20 structures of metals and alloys. M., MetalSvinets Ostalnoelurgi, 1964, p. 155-173.

3. Maltsev M.V. Modified

Claims (1)

Formula of the invention Modifier for pre-eutectic and eutectic aluminum-silicon alloys containing sodium, characterized in that, in order to increase the mechanical properties of the alloys and increase the duration of the modification effect, lead is additionally introduced into it in the following ratio of components, wt.%: Sodium 4,5-20 Lead Else