SU1057161A1 - Modifier for aluminium alloys - Google Patents

Abstract

MODIFIER FOR A REMEMBERING OF ALLOYS, including sodium chloride and potassium chloride, characterized in that, in order to improve the mechanical properties of the alloy and increase the duration of the effect of gyrification, the modifier additionally contains titanium and an element selected from the group containing vanadium, chromium, molybdenum, The following ratio of components, wt.%: Potassium chloride 15-20 Titanium20-6 (1 Element selected from the group containing vanadium, chromium, molybdenum. 0.1-6; 0 Sodium chloride Remaining

Description

About SP 4 The invention relates to the metal of non-ferrous metals, in particular to the production of modified aluminum-silicon alloys containing less than 12% silicon. All aluminum alloys in the molten state are characterized by high activity towards the gaseous products located in the working space of the melting furnaces. In the interaction of the melt with the oxygen of the air, they form with the oxides of shlyumin and other metals that are part of the alloy. In order to obtain high-quality casting, all foreign inclusions should be removed from the melt by refining. To obtain a dense homogeneous structure, the alloy is modified, i.e. treated with salts or some metals in the amount of 0.5-1.0% of the melt weight. Mixtures of chloride and fluorine salts ij and 2 are widely used as modifiers. The disadvantages of the known modifiers include the fact that the effect of modification is retained for no more than one hour, as well as the low mechanical properties of the alloy. The closest to the proposed is the 3J modifier containing., Wt.%: Sodium chloride 52-57 Potassium chloride 30-35 Sodium fluorofluoride 10-15 The disadvantage of the known modifier is the absence of modification of aluminum alloys 2 hours after the introduction of the modifier. In addition, the mechanical properties of the alloy are slightly improved. The purpose of the invention is to improve the mechanical properties of the alloy, namely, the relative elongation, hardness and tensile strength of the alloy and increase the duration of the effect of modification. This goal is achieved by the fact that the modifier, including chlorine sodium and potassium chloride, additionally contains titanium and an element selected from the group containing vanadium, chromium, molybdenum, in the following ratio of components, wt.%: Potassium chloride 15-20 Titanium 20-bO An element selected from the group containing vanadium, chromium, molybdenum, 0.5-3 Sodium chloride Else The modifier is introduced into the melt in an amount of 0.9-3.0% by weight of the melt. In an electric melting furnace with a graphite crucible, an amount of 100 kg is prepared in an alkali alloy, wt.%: Silicon 8.5 Copper2.25 Manganese 0.35 Magnesium O, 5 Aluminum Rest Alloy is refined with hexachloroethane and fused into pigs weighing 15 kg each . In an electric furnace, an alloy of the indicated composition is melted in an amount of 15 kg. After refining and slag removal, the alloy at a temperature of 700 ° C is treated with a flux of known composition (according to the prototype) in an amount of 105 kg (Table 1, composition 1). From this alloy, samples are cast for microscopic examination: the 1st sample. After 60 minutes, the 2nd sample — after 90 minutes, the 3rd — after 150 minutes after the introduction of the modifier. Under similar conditions, experimental melting was carried out with the proposed composition modifier 2-7 listed in Table. 1. The amount of alloy in all examples is 15 kg, the amount of modifier introduced is 0.270 kg (1.8% by weight of the melt. After modification, pshak is removed from the bath surface and samples are cast to determine the ultimate strength, elongation and hardness. Table 2 The mechanical properties of the alloys are shown depending on the modifier used.Table 3 shows the results of studying the microstructure of alloy samples cast through 0, 90 and 150 minutes after modifying with the modifiers shown in Table 1. From Table 3 it follows that all predictable modifiers provide a literal (up to 2.5 hours) preservation of the setting effect. The economic effect from the introduction of the proposed modifier is the possibility of using cheaper cast hypoeutectic silumin in the casting of mass production parts and amounts to 500 thousand rubles per year.

.Table I

Sodium Chloride 54.5 66.6 14.0

Potassium chloride 32.5 14.0 21.0

19.0 61.0

Titanium 0.44.0

Vanadium

Chromium

Molybdenum

Sodium fluorosilicate13.0

0.8 2.1 1.8 2.1 1.8 2.1 1.8

14,021,014.0 21.0

19,061,019.0 61.0

6.0

0.2

0.16.0

table 2

80 83 90 83 90 83 90 66.8 12.0 66.9 12.0 Smelting and Microscopic Sample Results Sample I modifier | Sample | Time after modification- Conclusion 10571616 Table 3 tsiro, min

Claims (1)

MODIFIER FOR ALUMINUM ALLOYS, including sodium chloride and potassium chloride, characterized in that, in order to improve the mechanical properties of the alloy and increase the duration of the modification effect, the modifier additionally contains titanium and an element selected from the group consisting of vanadium / chromium, molybdenum, in the following the ratio of components, wt.%: Potassium chloride 15-20 Titanium 20-6Q An element selected from the group consisting of vanadium, chromium, molybdenum Sodium chloride 0.1-6.0 Else