RU2280705C2 - Aluminum-based alloy and articles made from this alloy - Google Patents

Abstract

FIELD: metallurgy of aluminum-based alloys on base of Al-Mg-Mn system for manufacture of armored semi-finished products and articles for aviation and shipbuilding and other civil equipment.

SUBSTANCE: proposed alloy contains the following components, mass-%: magnesium, 4.2-6.5; manganese, 0.5-1.2; zinc, up to 0.2; chromium, up to 0.2; titanium, up to 0.15; silicon, up to 0.25; iron, up to 0.3; copper, up to 0.1; zirconium, 0.05-0.3 and at least one element selected from group containing: scandium, 0.05-0.3; beryllium, 0.0001-0.01; yttrium, 0.001-0.1; neodymium, 0.001-0.1; cerium, 0.001-0.1, the remainder being aluminum. Proposed alloy and articles made from it possesses high resistance to ballistic action of various projectiles due to optimal strength characteristics, optimal structure and plasticity characteristics.

EFFECT: high resistance to ballistic action of projectiles; enhanced corrosion resistance and weldability; reduced mass.

3 cl, 1 dwg, 3 tbl, 3 ex

Description

The invention relates to the field of metallurgy of aluminum-based alloys, in particular to an aluminum alloy based on the Al-Mg-Mn system, used for the manufacture of armored semi-finished products and products from it, used in aircraft and shipbuilding, in the production of ground armored vehicles and other objects civil and special purposes.

The greatest application in the manufacture of armored semi-finished products and products from it was received by aluminum alloys of two systems: Al-Zn-Mg (V.I. Elagin, V.V. Zakharov, A.M. Dritz Structure and properties of alloys of the Al-Zn-Mg system, M.: Metallurgy, 1982, p. 210) and Al-Mg-Mn (Aluminum. Properties and physical metallurgy. Ed. By J. E. Hatch, M .: Metallurgy, 1989, p. 356).

In accordance with US military standards: MIL-A-46027 F (MR) and MIL-A-46063 E (copies of the standards can be obtained from the standardized document ordering department at: Standartization Documents Order Desk, Bidg. 4D, 700 Robbins Avenue, Philadelphia , PA 19111-5094, approved for general use without any restrictions) armored semi-finished products from aluminum-based alloys must withstand the ballistic effects of two different types of shells fired at a given angle to the target. One of them is an armor-piercing projectile (type AP), used for through penetration of armor, the distinguishing feature of which is a pointed shock end. The other is a fragmentation projectile (type FS), characterized by a blunt impact end and, as a result, tends to create flying fragments from the inside of the armor, even if the projectile fails to penetrate it. Therefore, speeds lower than penetration rates should be taken into account when testing armor with an FS shell.

As practice shows, the aluminum alloys of one system used to make armor, superior to the aluminum alloys of another system in the case of one type of projectile, can be inferior to the aluminum alloys of the same system in the case of another type of projectile.

Armor semi-finished products and products from them should have the optimal combination of certain properties, namely, have strength characteristics sufficient to provide the required ballistic level of protection and have a viscous metal structure and increased ductility, the combination of which will reduce or eliminate the formation of flying fragments from the inside of the armor and thereby provide enhanced performance for both types of shells.

In addition, the stability of these properties over time is of no small importance.

It should be noted that armored semi-finished products and products made of them from aluminum-based alloys are used not only where resistance to ballistic action is required, but also in cases where weight reduction, high corrosion resistance, and weldability are important factors. As practice shows, corrosion resistance and weldability can also vary for different alloys.

Known aluminum-based alloy - 7039 (the alloy designation is in accordance with the alloy numbers and meets the definitions registered by the Aluminum Association, Washington, USA), used for the manufacture of armored semi-finished products and products from it, containing, wt.%:

Magnesium 2,3-3,3 Manganese 0.1-0.4 Zinc 3.5-4.5 Chromium 0.15-0.25 Titanium up to 0.1 Silicon up to 0.3 Iron up to 0.4 Copper up to 0.1 Aluminum rest

(U.S. Military Standard: MIL-A-46063 E).

The disadvantages of this alloy are the increased cost of the alloy, the increased weight of the armored semi-finished products from it, the high complexity of manufacturing and the low quality of the armored semi-finished products from it.

The reasons for the occurrence of the above disadvantages when using the known alloy include the fact that the known alloy has a high content of zinc having a high density and high cost; manufacturing technology of alloy semi-finished products and products contains additional operations - hardening and aging, including finished products; increased strength and reduced plasticity of the alloy leads to a relatively low resistance of armored semi-finished products and products to the effects of shells of the FS type and, as a result, the presence of flying fragments from its inside, moreover, through penetration of armored semi-finished products and products by an AP shell, the core of the shell is painted on single fragments; high zinc content, as well as high total zinc and magnesium content in the alloy negatively affects its corrosion resistance (V.I. Elagin, V.V. Zakharov, A.M. Drits. Structure and properties of Al-Zn-Mg. M alloys .: Metallurgy, 1982, p.139); the difference in the mechanical properties of the weld, heat-affected zone and the base metal leads to a reduced resistance of the weld to ballistic action and corrosion (L.F. Mondolfo Structure and properties of aluminum alloys, M .: Metallurgy, 1979, p. 555).

Known alloy based on aluminum, used for the manufacture of armored semi-finished products and products containing, wt.%:

Magnesium 2.6-3.5 Manganese 0.2-0.45 Zinc 5.5-6.3 Chromium 0.2-0.4 Titanium 0.1-0.3 Silicon up to 0.2 Iron up to 0.3 Copper up to 0.2 Aluminum rest

Moreover, the total content of zinc and magnesium is 9.0-10.4 wt.%, And the ratio of zinc to magnesium content is 2.0-2.8.

(RF patent No. 2044098, IPC ⁶ C 22 C 21/10, published in Bulletin No. 26 for 1995)

The disadvantages of this alloy are the increased cost of the alloy, the increased weight of semi-finished products and products, the high complexity of manufacturing and the low quality of semi-finished products and products from it.

The reasons for the occurrence of the above disadvantages when using the known alloy include the fact that the known alloy has a high content of zinc having a high density and high cost; manufacturing technology of alloy semi-finished products and products contains additional operations - hardening and aging, including finished products; the increased total content of zinc and magnesium further increases the strength and reduces the ductility of the alloy (V.I. Elagin, V.V. Zakharov, A.M. Drits. Structure and properties of alloys of the Al-Zn-Mg system. M .: Metallurgy, 1982, p.138), which further reduces the resistance of semi-finished products and products to the effects of shells of the FS type and, as a result, to the presence of flying fragments from its inside; moreover, during through penetration of semi-finished products and products by an AP-type projectile, the core of the projectile is painted into separate fragments; the optimum ratio of zinc and magnesium for alloys of this system (of the order of 2, 5) from the point of view of mechanical and ballistic properties negatively affects weldability (V.I. Elagin, V.V. Zakharov, A.M. Drits Structure and properties of alloys of the Al system -Zn-Mg. M: Metallurgy, 1982, p.142); high zinc content, as well as high total zinc and magnesium content in the alloy negatively affects its corrosion resistance (V.I. Elagin, V.V. Zakharov, A.M. Drits. Structure and properties of Al-Zn-Mg. M alloys .: Metallurgy, 1982, p.139); the difference in the mechanical properties of the weld, heat-affected zone and the base metal leads to a reduced resistance of the weld to ballistic action and corrosion (L.F. Mondolfo Structure and properties of aluminum alloys, M .: Metallurgy, 1979, p. 555).

Thus, armor semi-finished products and products from alloys of the Al-Zn-Mg system are characterized by reduced performance due to increased weight, poor weldability and poor quality of the weld, and generally favorable ballistic characteristics of armored semi-finished products and products, demonstrated by the ballistic impact of shells like ARs are seriously degraded over time due to their reduced corrosion resistance.

Known alloy based on aluminum - 5083 (alloy designation is in accordance with the numbers of alloys and meets the definitions registered by the Aluminum Association, Washington, USA), used for the manufacture of armored semi-finished products and products, containing, wt.%:

Magnesium 4.0-4.9 Manganese 0.4-1.0 Zinc up to 0.25 Chromium 0.05-0.25 Titanium up to 0.25 Silicon up to 0.4 Iron up to 0.4 Copper up to 0.1 Aluminum rest

(U.S. Military Standard MIL-A-46027 N (MR)).

The disadvantage of this alloy is the low quality of semi-finished products and products from it.

The reasons for the occurrence of the aforementioned disadvantage when using the known alloy include the fact that the known alloy is characterized by reduced strength and increased ductility and, as a consequence, relatively low resistance to the effects of AP shells; Moreover, the increased silicon content (more than 0.3 wt.%) somewhat reduces the strength characteristics of the alloy (Industrial aluminum alloys Ref. Ed. Alieva SG, Altman MB, Ambartsumyan SM and others, M .: Metallurgy, 1984, p. 47).

The closest alloy in chemical composition and purpose to the claimed aluminum-based alloy is an alloy containing, wt.%:

Magnesium 5.0-6.5 Manganese 0.6-1.2 Zinc up to 0.75 Chromium up to 0.2 Titanium up to 0.15 Silicon up to 0.4 Iron up to 0.27 Copper up to 0.1 Zirconium up to 0.15 Aluminum rest

Moreover, the total content of magnesium and manganese is 6.0-6.7 wt.%.

(US Patent No. 4469537, IPC ⁶ C 22 C 21/06.

The disadvantage of this alloy, taken as a prototype, is the low quality of semi-finished products and products from it.

The reasons for the occurrence of the above disadvantages when using the known alloy adopted for the prototype include the fact that the known alloy is characterized by reduced strength and increased ductility and, as a consequence, relatively low resistance to armor-piercing shells with a pointed impact end; increased silicon content (more than 0.3%) somewhat reduces the strength characteristics of the alloy (Industrial aluminum alloys Ref. Ed. Alieva SG, Altman MB, Ambartsumyan SM and others, M .: Metallurgy, 1984 , p. 47); Moreover, the increased zinc content negatively affects the corrosion resistance.

The problem to which the invention is directed, is to develop an armored alloy based on aluminum, intended for the manufacture of armored semi-finished products and products free from the disadvantages listed above and inherent in known technical solutions. The technical result achieved by the implementation of the invention is to obtain an alloy and semi-finished products and products from it, which would combine the best performance characteristics of semi-finished products and products obtained from the above alloys of the Al-Mg-Mn and Al-Zn-Mg systems, namely in increasing the resistance of semi-finished products and products made according to this invention, the ballistic effect of various types of shells due to the achievement of constant in time optimal strength characteristics, optimal with ruktury and ductility characteristics, and also in improving the corrosion resistance and would possess desirable properties such as good weldability and low weight.

The problem with the achievement of the aforementioned technical result in the implementation of the invention is solved by the fact that the known aluminum-based alloy used for the manufacture of armored semi-finished products and products containing magnesium, manganese, zinc, chromium, titanium, silicon, iron, copper, zirconium, additionally contains at least one element selected from the group comprising scandium, beryllium, yttrium, neodymium, cerium in the following ratio of components, wt.%:

Magnesium 4.2-6.5 Manganese 0.5-1.2 Zinc up to 0.2 Chromium up to 0.2 Titanium up to 0.15 Silicon up to 0.25 Iron up to 0.30 Copper up to 0.1 Zirconium 0.05-0.3

At least one element selected from the group including, wt.%:

Scandium 0.05-0.3 Beryllium 0.0001-0.01 Yttrium 0.001-0.1 Neodymium 0.001-0.1 Cerium 0.001-0.1 Aluminum rest

The aluminum-based alloy used for the manufacture of armored semi-finished products and products differs from the prototype both qualitatively (additionally contains at least one element selected from the group including scandium, beryllium, yttrium, neodymium, cerium) and quantitatively (low zinc content) silicon, high zirconium content).

The alloy maintains a certain ratio of magnesium and manganese, which is necessary to achieve the optimal combination of strength and plastic characteristics of an armor alloy. Moreover, an increase in the positive influence of these elements on the ballistic characteristics of semi-finished products and alloy products is achieved by introducing additional alloying elements into the alloy.

We found that when the alloy used for the manufacture of armored semi-finished products and products contains at least one element selected from the group including scandium, beryllium, yttrium, neodymium, cerium in the indicated quantities, an unexpected increase in the resistance of semi-finished products and ballistic products is observed impact for various types of shells, which is explained by the achievement of optimal mechanical characteristics for alloys for this purpose, namely, increasing the strength limit to the required level and the yield strength and elongation required of the alloy structure.

The introduction of one or more elements from the group: scandium, beryllium, yttrium, neodymium, cerium in the indicated amounts, contributes to the formation of a homogeneous, fine-grained structure, inhibition of recrystallization processes, and achievement of optimum strength and plastic characteristics for an armor alloy. With the content (together or separately) of scandium and beryllium, respectively, below 0.05 and 0.0001 wt.%, And yttrium, neodymium, cerium below 0.001 wt.%, The strength properties of the alloy decrease, and with the content (together or separately) of scandium and beryllium respectively, above 0.3 and 0.01 wt.%, and yttrium, neodymium, cerium above 0.1 wt.% reduced plastic properties of the alloy.

Zirconium in the amount of 0.05-0.3 wt.% Is a modifying additive and provides structural hardening in semi-finished products. When the zirconium content is less than 0.05 wt.%, The strength properties of the alloy are reduced, when the zirconium content is more than 0.3 wt.%, The plastic properties of the alloy are reduced.

The content of zinc and silicon in it is reduced to 0.2 wt.% And 0.25 wt.%, Respectively, in order to improve weldability and increase the corrosion resistance of the alloy.

Various semi-finished products can be made from the proposed aluminum-based alloy: sheets and plates, stampings, extruded products. Various products can be obtained from the semi-finished products of the proposed alloy, for example, panels for covering the wings and fuselages of aircraft, helicopter hulls, fuel tanks, hull structures of light sea and river vessels and their superstructures, vehicle hulls, etc.

In the proposed product, made of an alloy based on aluminum used for the manufacture of armored semi-finished products, the technical result is achieved by the fact that the alloy is used as the workpiece material in the following ratio of components, wt.%: Magnesium 4.2-6.5; manganese 0.5-1.2; zinc up to 0.2; chrome up to 0.2 titanium up to 0.15; silicon up to 0.25; iron up to 0.3; copper up to 0.1; zirconium 0.05-0.3; at least one element selected from the group consisting of scandium 0.05-0.3; beryllium 0.0001-0.01; yttrium 0.001-0.1; neodymium 0.001-0.1; cerium 0.001-0.1; aluminum rest.

The invention is illustrated by a diagram showing the influence of the chemical composition of the alloy on the mechanical properties of armored semi-finished products and products.

The significance of the chemical composition of the alloy for the manufacture of, in particular, armor plates and plates is illustrated in the diagram, which shows the increase in strength and plastic characteristics of armor sheets and plates, which are directly related to increasing the level of ballistic protection for various types of shells (AP and FS). This increase can be achieved by introducing into the alloy at least one element selected from the group consisting of scandium, beryllium, yttrium, neodymium, cerium, and reducing the content of silicon and zinc. These data are a comparison of examples of three alloys: alloy A - alloy 5083, alloy B - alloy according to US patent No. 4469537, alloy C - alloy in accordance with the present invention.

To check the ballistic properties, we used plates with a thickness of the order of 38.1 mm, obtained from ingots cast from alloys 1, 2, 3, 4, 5, 6, 7, 8. The compositions of these alloys are shown in Table 1.

Additionally, an ingot of alloy 7039 was cast and rolled to an experimental plate 38.1 mm thick using traditional technology for this alloy for this purpose.

It should be noted that casting and rolling were carried out on industrial equipment on which alloys of these systems are manufactured on an industrial scale.

The ballistic properties of the plates were determined by firing the plates with 7.62 mm rounds of ammunition (type AP) and 30 mm shells (type FS).

Prior to testing, the experimental armor plates underwent heat treatment at a temperature of 14 ° C for at least 8 hours.

Plates were installed at a distance of 58 meters with a deviation angle of 0 °. Behind the test armored plates parallel to them at a distance of 15 cm were installed sheets - "witnesses" of aluminum alloy 2024-T3 with a thickness of 0.5 mm. The definition of the ballistic limit of defense consisted of an equal number of credible hits of shells at full and partial penetration speeds. A test hit means a strike, as a result of which a test sheet was hit by a projectile under normal flight conditions and separated from another strike or from the edge of the sheet, hole, crack or other intact zone with a length of at least two calibers. Full penetration is understood to mean penetration in which a projectile or one or more fragments of a projectile or sheet pass beyond the back of the test sheet and pierce the “witness” sheet. Partial penetration is understood as a blow, as a result of which the test sheet was damaged (penetration, exit of the core of the projectile from the plate, the presence of chips on the inside, the presence of cracks, etc.), but not related to full penetration.

All ballistic limits of defense were calculated on the basis of the highest values of the velocity of the projectile for partial penetration and the lowest indicators of the velocity of the projectile for full penetration. Shooting continued until a ballistic limit of protection of four series of shots was reached with a maximum speed separation of 18.3 meters per second or a ballistic limit was sewn of six series of shots with a maximum speed separation of 27.4 meters per second. By spacing is meant the difference between the highest velocity of the projectile with partial penetration and the lowest velocity of the projectile with full penetration.

The speed of the bullet was selected by changing the weight of a sample of gunpowder. The speed of the bullet was measured by the Luch-81 station.

The results of mechanical and ballistic tests are presented in table.2.

The data given in Table 2 show an improvement in the ballistic properties of armored semi-finished products and products (which is reflected in an increase in the projectile velocity necessary for hitting armored semi-finished products and products), the increase of which is achieved by increasing the strength and plastic properties of semi-finished products, and increasing the viscosity of the metal structure.

Tests for stress corrosion were carried out on plates obtained from alloys defined in table 1. Ring samples (C-shaped half rings) cut from plates in the transverse direction with respect to rolling were immersed in a 3.5% NaCl solution prepared in distilled water under a voltage of 206.4 MPa in the transverse direction. This direction was chosen because aluminum alloys are most susceptible to stress corrosion in this direction. Diving was carried out for 10 minutes for every hour, followed by 50 minutes of air drying. This cycle was repeated throughout the test, which was determined at 30 days.

Tests for the weldability were carried out on plates obtained from alloys defined in Table 1. Samples for testing the weldability were obtained as follows, chemically pretreated surfaces of the base metal and the welding (filler) wire were subjected to arc welding in an inert gas environment. As a welding (filler) wire, Amg5 alloy wire was used.

Tests on the quality of weldability of samples from armor plates were made

- the presence of penetration through the seam of an easily flowing liquid (kerosene);

- to determine the mechanical properties of tensile samples taken from the weld zone with the definition of the efficiency of the weld.

The test results of plate samples for corrosion under tension and the weldability are given in table 3. The data given in table 3, indicate an increase in corrosion resistance and quality of welds.

Thus, the use of the proposed alloy will make it possible to obtain armored semi-finished products and products from them that have increased ballistic properties when exposed to various types of shells, high corrosion resistance and weldability, low weight.

Example 1

From alloys of compositions 3, 4, 5, 6, plates were obtained with a thickness of 38.1 mm from an ingot with a cross section of 260 × 1500 mm according to the following technology: homogenization of the ingot at a temperature of 470-490 ° C for 12 hours, hot rolling at a temperature of 420-450 ° C to a thickness of 65 mm, cold rolling to a thickness of 38.1 mm, straightening plates by stretching.

Example 2

From an alloy of composition 3, a pressed strip with a section of 20 × 60 mm was obtained from a pre-homogenized ingot with a diameter of 70 mm at a temperature of 470-490 ° C for 12 hours. The pressing temperature is 380-400 ° C.

Example 3

From the proposed alloy of composition 3, we obtained punching with a wall thickness of 60 mm from a round ingot with a diameter of 400 mm using the following technology: homogenization of the ingot at a temperature of 470-490 ° C for 12 hours, forging at a temperature of 370 ° C with a total degree of deformation of 40%, annealing at temperature 320-340 ° С for 8 hours, preliminary stamping at a temperature of 380 ° С with a total degree of deformation of 30%, annealing at a temperature of 320-340 ° С for 6 hours, final stamping at a temperature of 380 ° С with a total degree of deformation 40 %

Table 1 Alloy Spava Composition No. The content of components, wt.% Mg Mn Zn Cr Ti Si Fe Cu Zr Sc Be Y Nd Xie Al 5083 one 4.9 0.9 0.25 0.18 0.25 0.4 0.4 0.1 Rest US Pat. No. 4,496,537 2 5.5 0.8 0.75 0.15 0.15 0.4 0.27 0.1 0.14 Also Proposed 3 5.5 0.9 0.18 0.15 0.1 0.2 0.3 0.1 0.17 0.2 - - - - Also four 4.3 0.8 0.2 0.15 0.15 0.25 0.2 0.1 0.15 0.15 0.005 0.05 - - Also 5
6 5,0
6.2 0.6
1.15 0.17
0.19 0.1
0.15 0.1
0.12 0.15
0.2 0.25
0.3 0.1
0.1 0.25
0.15 -
- -
0.008 0.06
- 0.1
0.09 -
0,07 Also
Also Experienced 7 5.2 1,0 0.1 0.14 0.15 0.15 0.3 0.1 0.15 0.4 0.02 - 0.2 0.2 Also 8 6.3 0.6 0.2 0.1 0.1 0.2 0.25 0.1 0.25 0.001 - 0,0005 0,0005 0.0001 Also

table 2 Alloy Alloy composition no. Plate thickness, mm Mechanical properties Ballistic protection level, m / s σ _in , MPa σ _0.2 , MPa δ,% 7.62 mm armor-piercing 30 mm fragmentation 5083 one 38.1 370 255 8 718 732 Alloy according to US patent No. 4469537 2 38.3 390 270 eleven 725.2 739.3 Proposed 3
four
5
6 38.3
37.9
38.1
38,0 406
412
409
411 290
295
293
294 fifteen
fourteen
fourteen
fourteen 737.5
740.3
738.2
741.5 750.5
752.1
745.6
749.2 Experienced 7
8 38,2
37.8 398
387 265
278 8
eleven 727.1
719.4 732.5
738.0 7039 9 38.3 424 301 10 721.6 735.7

Claims (2)

1. The aluminum-based alloy used for the manufacture of armored semi-finished products and products containing magnesium, manganese, zinc, chromium, titanium, silicon, iron, copper, zirconium, characterized in that it additionally contains at least one element selected from the group including scandium, beryllium, yttrium, neodymium, cerium in the following ratio of components, wt.%: Magnesium 4.2-6.5 Manganese 0.5-1.2 Zinc Up to 0.2 Chromium Up to 0.2 Titanium Up to 0.15 Silicon Up to 0.25 Iron Up to 0.3 Copper Up to 0.1 Zirconium 0.05-0.3 at least one element selected from the group including, wt%: Scandium 0.05-0.3 Beryllium 0.0001-0.01 Yttrium 0.001-0.1 Neodymium 0.001-0.1 Cerium 0.001-0.1 Aluminum Rest 2. The product is made of an alloy based on aluminum used for the manufacture of armored semi-finished products, characterized in that the material used is an alloy with the following ratio of components, wt.%: Magnesium - 4.2-6.5; manganese - 0.5-1.2; zinc - up to 0.2; chrome - up to 0.2; titanium - up to 0.15; silicon - up to 0.25; iron - up to 0.3; copper - up to 0.1; zirconium - 0.05-0.3 at least one element selected from the group comprising scandium - 0.05-0.3; beryllium - 0.0001-0.01; yttrium - 0.001-0.1; neodymium - 0.001-0.1; cerium - 0.001-0.1; aluminum is the rest.