WO2006068536A1

WO2006068536A1 - Aluminium-based alloy and a product made thereof

Info

Publication number: WO2006068536A1
Application number: PCT/RU2005/000605
Authority: WO
Inventors: Evgeny Nikolaevich Kablov; Iosif Naumovich Fridlyander; Vladislav Valerievitch Antipov; Tatiyana Petrovna Fedorenko; Lubov Petrovna Lantsova
Original assignee: Federalnoe Gosudarstvennoe Unitarnoe Predpriyatie 'vserossiysky Nauchno-Issledovatelsky Institut Aviatsionnykh Materialov'
Priority date: 2004-12-21
Filing date: 2005-11-28
Publication date: 2006-06-29
Also published as: RU2278179C1

Abstract

The invention relates to an aluminium-based alloy of an Al-Cu-Mg group and to a product which is made thereof and used for aerospace engineering. The inventive alloy exhibits high strength and ductility characteristics, crack resistance, lifetime and increased lighting resistance. Said alloy has the following chemical composition (in mass %): 3.8-5.5 copper, 0.3-1.6 Mn, 0.2-0.8 Mg, 0.5·10-6-0.07 titanium, 0.5·10-6-0.1 tellurium, at least one element from a group containing 0.2-1.0 silver, 0.5·10-6-0.05 nickel, 0.5·10-6-0.1 zinc, 0.05-03 zirconium, 0.05-0.3 chromium, 0.5·10-6-0.15 iron, 0.5·10-6-0.1 silicium, 0.1·10-5-2. 7·10-5, the rest being aluminium. The alloy in the form of sheets is used as construction material for a skin and body frame in aerospace engineering.

Description

Aluminum-based alloy and product made from it

FIELD OF THE INVENTION The invention relates to the field of non-ferrous metallurgy, in particular to alloys based on aluminum of the Al-Cu-Mg system. Semi-finished products from these alloys are used as structural materials for aerospace engineering in the form of casing and power pack.

State of the art

Known alloy DLbch having the following chemical composition (% by weight):

Copper 3.8-4.9

Magnesium 1.2-1.8

Manganese 0.3-0.9

Iron <0.3

Silicon <0.2

Zinc <0, l

Titanium <0, l

Nickel <0.05 ^"

Aluminum Else (D American alloys of the 2000 Al-Cu-Mg system are also known, for example, an alloy having the following chemical composition (% by weight):

Copper 4.2-4.7

Magnesium 1.3-1.8

Manganese 0.8-1.3 Zirconium 0.08-0.15

Zinc <0.25

Titanium <0D5

Chrome ≤ OD

Iron <0D5

To jvrrsemnnyjdiy b <υ0, ДiZ2

The rest is aluminum (2) of its chemical composition (

Copper 3.8-4.5

Magnesium 1.2-1.8

Manganese 0.3-0.9

Iron <0D5

Silicon <0D5

Aluminum rest (3)

Known alloys and products from them, having high strength, ductility, durability, fracture toughness, low growth rate of fatigue cracks, in some cases have insufficient lightning resistance. This characteristic for a specific group of aerospace engineering products is decisive.

Known Russian alloy based on aluminum system Al-

Cu-Mg of the following chemical composition (% by weight):

Copper 3.8-4.5

Magnesium 1.2-1.6

Manganese 0.4-0.8

Titanium 0.01-0.07

Nickel 0.01-0.05

Hydrogen 2.7-10 ^'5 -5.0-10 ^"5

Aluminum Else (4) This alloy has an improved combination of tensile strength, fracture toughness and fatigue crack growth rate. A sheet made of this alloy has the following properties: σ _in = 460 MPa, K _c ^y = 55 MPaVm, d (21) / dN = l, l mm / ktsikl. However, the alloy has insufficient lightning resistance, which limits its use as a casing or power set in new generation aircraft.

Disclosure of invention

The subject of the present invention is the creation of an alloy having, in addition to high characteristics of strength, ductility, crack resistance, durability, increased lightning resistance for structural applications in aerospace engineering in the form of sheathing and power pack.

According to the present invention, an alloy based on aluminum of the Al-Cu-Mg system is proposed having the following chemical composition (% by weight):

Copper 3.8-5.5

Magnesium 0.3-1.6

Manganese 0.2-0.8

Titanium 0,5-10- Tellurium 0.5-10 ⁶ -0.07 ^"5 -0, l for at least one element selected from the group consisting of silver 0.2-1.0

Nickel 0.5-10 ^'6 -0.05 Zinc 0.5-10 ^"b -0D

Zirconium 0.05-0.3 Chrome 0.05-0.3

Iron 0.5-10 ^"6 -0D5

90 Silicon 0.5-10 ^'6 -0, l

Hydrogen 0D 10 ^"5 -2.7 10 ^{" 5}

Aluminum rest and product made from it

An increase in lightning resistance, as an important characteristic, ^is achieved by additional doping with tellurium.

The presence of tellurium causes the formation of a chemical compound with aluminum related to F-type semiconductors with electrical resistivity at room temperature

5-U ^"3 Ohm-m. The presence in the structure of the proposed alloy 100 semiconductor phase provides increased lightning resistance of the alloy and products made from it.

The presence of at least one element from the group, including silver, nickel, zinc, zirconium, chromium, iron, silicon, hydrogen provides an increase in the strength characteristics of the alloy — tensile strength and yield strength.

Implementation example

In laboratory conditions, 4 alloy ingots were cast. The chemical compositions of the proposed and known alloys are shown in table 1, where alloys 1-7 are examples of alloys according to the invention, and alloy 8 is an example of an alloy according to the patent

From ingots, by pressing a strip and subsequent hot and cold rolling, sheets with a thickness of 2.5 mm were obtained. Pressing was carried out at 430 ⁰ C, and hot rolling at 440-450 ⁰ C. The sheets were cut into blanks, which were tempered from temperature 495-510 ⁰ C in water and aged at a temperature of 170-190 ⁰ C for 12-20 hours. Samples for testing for lightning resistance and mechanical properties were made from these blanks. Test results

120 are shown in table 2.

Tests for lightning resistance were carried out in accordance with the methods and standards adopted in the Russian Federation, with discharge parameters A + C, where A is the main discharge pulse, C is the constant current component. Maximum current value 1 = 200 kA,

125 transferred charge Q = 20 C, pulse duration 50 μs.

The mechanical properties of sheets under tension (tensile strength σ _in , yield strength σ _{0; 2} , elongation δ) were determined according to GOST 1497-84 on samples with a working part width of 10-15 mm.

130 Fatigue crack growth rate (d (21) / dN) was determined from

OCTl 90268-84 on plates 200x600 mm in size with a central slot at ΔK = 15.5 MPaVm under the following conditions of fatigue loading: σ _max = 100 MPa, R = 0.1; f = 5 Hz.

Fracture VISCOSITY K / was determined by OCTl 90356-84 on

135 plates 200x600 mm in size with R = 0.1; f = 5 Hz.

Low-cycle fatigue (MCU) was determined according to GOST 25.502-91 on samples with an aperture of size 30x200 mm at f = 0.17 Hz, R = O, K _t = 2.6.

The results show that the proposed alloy

140 in comparison with the known alloy has almost the same characteristics of strength, ductility, crack resistance, durability. However, according to lightning resistance, determined by the size of the damage from the side of the lightning strike and the preservation of the strength of the sheets after a lightning strike, the proposed

145 alloy in comparison with the known alloy has superiority on 20-25%.

Thus, the use of the proposed alloy as a structural material for aerospace engineering in the form of a casing and a power set of sheets provides a significant increase in lightning resistance.

Table 1

table 2

Mechanical properties of alloys

Oo

Literature

1. OCTl 90048-90.

2. U.S. Patent JYs 4,336,075.

3. US patent N ₂ 5,213,639.

4. RF patent JNs 2163941.

Claims

Claim

1. An aluminum-based alloy containing copper, magnesium, manganese, titanium, characterized in that it additionally contains tellurium and at least one element from the group: silver, nickel, zinc, zirconium, chromium, iron, silicon, hydrogen , with the following ratio of components (% by weight):

Copper 3.8-5.5

Magnesium 0.3-1.6

Manganese 0.2-0.8 Titanium 0.5-10 ^"b -0.07

Tellurium 0.5-10 ^"5 -0, l at least one element from the group containing Silver 0.2-1.0 Nickel 0.5-10 ^{~ b} -0.05

Zinc 0.5-10 ^"b -0, l

Zirconium 0.05-0.3

Chrome 0.05-0.3

Iron 0.5-10 ^'b -0.15 Silicon 0.5 10 ^"6 -0D

Hydrogen 0, l-10 ^"5 -2.7-10 ^{" 5}

Aluminum rest

2. The product is made of an alloy based on aluminum, characterized in that the alloy has the following chemical composition

(% by weight):

Copper 3.8-5.5

Magnesium 0.3-1.6

Manganese 0.2-0.8 Titanium 0.5-10- ^b -0.07

Tellurium 0.5-10 ^"5 -0, l at least one element from the group consisting of

Silver 0.2-1.0 Nickel 0.5-10 ^"6 -0.05

Zinc 0.5-10 ^"6 -0, l

Zirconium 0.05-0.3

Chrome 0.05-0.3

Iron 0.5-10 ^"6 -0.15 Silicon 0.5-10 ^{" b} -0D

Hydrogen 0, l-10 ^"5 -2.7-10 ^{" 5}

Aluminum rest