RU2599590C1 - Structural wrought non-heat-treatable aluminium-based alloy - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to wrought non-heat-treatable aluminium-based alloys intended for use in the form of deformed semi-finished products as structural materials. Alloy contains, wt%: magnesium 5.7-6.3, titanium 0.01-0.03, beryllium 0.0001-0.005, zirconium 0.05-0.12, scandium 0.18-0.26, manganese 0.2-0.55, iron 0.05-0.3, silicon 0.03-0.2, inevitable impurities: copper not more than 0.1, zinc not more than 0.1, the remaining impurities not more than 0.05 each and maximum 0.15 in total; aluminium - the rest, at the content of hydrogen in the alloy of 0.1-0.35 cm³ per 100 g of metal and the relation of the content of iron to silicon content equal to or more than 1.

EFFECT: technical result of the invention is improved strength characteristics of the alloy.

1 cl, 2 tbl, 1 ex

Description

The invention relates to the field of metallurgy, in particular to deformable thermally unstrengthened aluminum-based alloys intended for use in the form of deformed semi-finished products, mainly in the form of rolled plates and sheets, as a structural material in space technology, aircraft manufacturing, transport engineering and other technical fields.

Known in metallurgy are structural deformable thermally unstrengthened alloys based on aluminum, in particular an alloy of the following chemical composition, wt. %:

Magnesium 5.5-6.5 Manganese 0.8-1.1 Zirconium 0.02-0.1 Beryllium 0.0001-0.005 Impurities, not more than: copper 0.05 zinc 0.2 gland 0.2 silicon 0.2 Aluminum Rest,

(Aluminum alloys. Industrial wrought, sintered and cast aluminum alloys. Reference guide. - M.: Metallurgy. 1972. P. 44).

However, the existing alloy has low strength properties in the annealed state.

Known structural deformable thermally unstrengthened alloy based on aluminum (patent RU No. 2233345, M. Cl. C22C 21/08 - prototype) of the following chemical composition, wt. %:

Magnesium 5.0-5.6 Titanium 0.01-0.03 Beryllium 0.0002-0.005 Zirconium 0.05-0.12 Scandium 0.16-0.26 Cerium 0,0002-0,0009 Manganese 0.15-0.5 A group of elements including iron and silicon 0.05-0.12 Aluminum Rest,

however, the ratio of iron to silicon should be equal to or greater than unity.

The known alloy has insufficiently high strength properties with good deformability, high corrosion resistance and good weldability.

A structural deformable thermally non-hardenable aluminum-based alloy is proposed, containing magnesium, titanium, beryllium, zirconium, scandium, manganese, iron and silicon, which additionally contains hydrogen and inevitable impurities of copper, zinc and other elements, and the components are taken in the following ratio, wt. %:

Magnesium 5.7-6.3 Titanium 0.01-0.03 Beryllium 0.0001-0.005 Zirconium 0.05-0.12 Scandium 0.18-0.26 Manganese 0.2-0.55 Iron 0.05-0.3 Silicon 0.03-0.2 Hydrogen 0.1-0.35 cm ³ / 100g metal Inevitable impurities, not more than: copper 0.1 zinc 0.1 each of the other elements 0.05 sums of other elements 0.15 Aluminum Rest,

however, the ratio of iron to silicon should be equal to or greater than unity.

The proposed alloy differs from the known one in that it additionally contains hydrogen and inevitable impurities of copper, zinc and other elements, and the components are taken in the following ratio, wt. %:

Magnesium 5.7-6.3 Titanium 0.01-0.03 Beryllium 0.0001-0.005 Zirconium 0.05-0.12 Scandium 0.18-0.26 Manganese 0.2-0.55 Iron 0.05-0.3 Silicon 0.03-0.2 Hydrogen 0.1-0.35 cm ³ / 100g metal Inevitable impurities, not more than: copper 0.1 zinc 0.1 each of the other elements 0.05 sums of other elements 0.15 Aluminum Rest,

however, the ratio of iron to silicon should be equal to or greater than unity.

The technical result is an increase in strength characteristics, which allows to increase the characteristics of the weight return of structures, in particular, spacecraft structures.

With the proposed content and ratio of components in the proposed alloy due to the dispersed precipitates of secondary intermetallic compounds containing aluminum, scandium, zirconium and other transition metals that are part of the alloy, a high level of strength properties is ensured. At the same time, the matrix, which is mainly a solid solution of magnesium and manganese in aluminum and has a large plasticity margin, provides good deformability during alloy processing by pressure, in particular during hot and cold rolling. Hydrogen in the indicated amount forms an interstitial solid solution, which additionally increases the high-temperature ductility of the matrix and grain boundaries, improving the deformability of the alloy during hot deformation. The regulated value of the ratio of iron to silicon content at their indicated content optimizes the morphology of excess intermetallic phases containing mainly aluminum, iron and silicon, contributing to an increase in strength properties while maintaining ductility and ensuring good casting properties of the alloy. The regulated content of inevitable impurities of copper, zinc and impurities of each of the other elements and their sum ensures the stability of the chemical composition of the alloy. The specified amount of inevitable impurities of other elements can be provided by the technology of alloy production without chemical analysis.

Example

Received the proposed alloy from a mixture consisting of aluminum grade A85, magnesium grade Mg95, double alloys aluminum-titanium, aluminum-beryllium, aluminum-zirconium, aluminum-scandium, aluminum-manganese, aluminum-iron and silumin. The alloy was prepared in an electric resistance furnace. The required hydrogen content and complete solubility of the alloys containing refractory metals were ensured by overheating of the melt. The content of alloying elements and impurities of copper and zinc was determined by chemical analysis. The content of other impurities was provided by production technology. The hydrogen content was determined in accordance with GOST 21132.1-98. Semi-continuous casting was used to cast flat ingots with a section of 165 × 550 mm. The chemical composition of the alloy is shown in table 1.

The ingots were homogenized, after which they were cut into measuring blanks 950 mm long, which were then milled to a thickness of 145 mm. The machined workpieces were subjected to multi-pass hot rolling at a temperature of 390 ° C with a total compression of 84%. Received hot-rolled plates with a thickness of 23 mm The mechanical properties (tensile strength σ _in , yield strength σ _0.2 , elongation δ) of the plates in the annealed state were determined by tensile testing in accordance with GOST 1497-84 of cylindrical samples cut from plates in the direction along (D) and across ( P) rolling. The mechanical properties of plates made of the prototype alloy of the average chemical composition made in the same way were also determined.

The test results are shown in table 2. As can be seen from table 2, the proposed alloy has higher strength characteristics compared to the known. The use of the proposed alloy as a structural material will reduce the weight of the structure by 5-7%, which is fundamentally important for space technology products.

All types of deformed semi-finished products can be made from the proposed alloy. Due to good weldability and high corrosion resistance, characteristic of deformable thermally unstrengthened alloys based on aluminum, the proposed alloy can be used in welded structures both as a base material and as a filler material in fusion welding.

Claims (1)

Structural deformable thermally non-hardening aluminum-based alloy containing magnesium, titanium, beryllium, zirconium, scandium, manganese, iron, silicon, copper, zinc and inevitable impurities, characterized in that it additionally contains hydrogen in the following ratio of components, wt. %:
magnesium 5.7-6.3 titanium 0.01-0.03 beryllium 0.0001-0.005 zirconium 0.05-0.12 scandium 0.18-0.26 manganese 0.2-0.55 iron 0.05-0.3 silicon 0.03-0.2 inevitable impurities: copper no more than 0.1 zinc no more than 0.1 other impurities in total not more than 0.15 with each content not more than 0.05 hydrogen 0.1-0.35 cm ³ / 100g metal aluminum rest,
with a ratio of iron to silicon equal to or greater than unity.