Method of extruding semis of high-strength aluminium alloy and parts thus made

FIELD: metallurgy.

SUBSTANCE: proposed method comprises casting the ingots of alloy containing the following components in wt %: zinc - 6.-4.1, magnesium - 0.6-1.1, manganese - 0.2-0.5, zirconium - 0.05-0.12, chromium - 0.05-0.15, copper - 0.1 -0.2, titanium - 0.01 -0.06, molybdenum - 0.01 -0.06, aluminium making the rest, at the temperature of 690-710°C and casting rate of 25-50 mm/min. Ingots are homogenised at 450-470°C for 8-12 hours and subjected to hot forming at 10-530°C and outflow rate of 0.1-4.0 m/min. Besides it includes air or air-water mix quenching and two-step ageing: at 90-110°C for 6-12 hours and at 160-190°C for 4-10 hours.

EFFECT: production of log parts with high operating properties.

4 cl, 1 ex, 6 tbl, 4 dwg

 

The present invention relates to a method of production of long, thin-walled panels and profiles designed for use on railway vehicles, but is not limited to this area of high strength aluminum alloy having the following ratio of components, wt.%:

Zinc 3,6-4,1

Magnesium 0,6-1,1

Manganese 0,2-0,5

Zirconium 0,05-0,12

Chrome 0,05-0,15

Copper is 0.1-0.2

Titanium 0,01-0,06

Molybdenum 0,01-0,06

Aluminum else

For almost 200-year history of railway transport carriage went from wooden structures of the body to the integrated aluminum and hybrid structures.

The transition to the new structural materials has always been accompanied by improvement of the technical characteristics of the rolling stock, changes in design and technology of its production, the reduction in the unit cost of material, financial and energy resources per unit of useful work, for example, one passenger-kilometer.

The use of large extruded panels allows for a 40% reduction in the complexity of manufacture of the body and reduce its weight up to 7.5 tons for cars with a length of 26 m, compared with 11 tons for the same body of steel.

The improvements in this technology have led to even greater, up to two times compared to steel, to reduce the cost of lying is neither a manufacturer of aluminum truck bodies. The full cost of a typical aluminum body is less than 85% of the cost of conventional steel body.

Technology of production cars from large aluminum extrusions and panels is a cost-effective solution. Large profiles can replace many complex classical details. Extruded profiles can be supplied ready for mounting integral parts. Such technologies can be used in many areas of technology. Existing advantages and possible applications of products from aluminum alloys, allow them to compete successfully with steel structures

Aluminum alloys, which are produced panels intended for use in the building must meet the following requirements:

1. To have the necessary strength, high energy fracture, high resistance to cyclic loads that act on the cars in their motion, high corrosion resistance. [1, 6, 8].

2. It should have good adaptability in engineering manufacture (well welded argon-arc welding, have a low tendency to cracking during welding, the loss of strength of the metal in the weld should not exceed 0,85 from the base metal, to have a certain stock plasticsnet is to make small edits and molds).

3. Since the volume of production of semi-finished products for car building large, the alloys should have high processability in extrusion production, namely high flow rate; low specific pressure; pressing complex thin-walled products, including hollow, and have a broad temperature interval of existence and the high stability of the solid solution in the main alloying components in aluminum, providing the possibility of quenching on the press.

Known aluminum alloy (Patent RF №2288293, publ. 27.11.2006) corresponding to the above requirements and having the following chemical composition, wt.%:

Zinc 3,6-4,1

Magnesium 0,6-1,1

Manganese 0,2-0,5

Zirconium 0,05-0,12

Chrome 0,05-0,15

Copper is 0.1-0.2

Titanium 0,01-0,06

Molybdenum 0,01-0,06

Aluminum else.

There is a method of manufacture of products made of wrought aluminium alloys containing at least one transition metal, comprising the following steps: heating the ingot to a temperature of preliminary plastic deformation 262-398°C with a holding time of 0.5 to 7 hours, prior plastic deformation at this temperature, the heat before the final plastic deformation to a temperature 405-445°C, holding at this temperature for 0.5-7 h and subsequent final plastic deformation, heat treatment is denied (RF Patent No. 2152451).

A known method of producing semi-finished products made of alloys of the system Al-Zn-Mg-Cu with high static mechanical characteristics, consisting of the following operations: two-stage homogenization temperature of 460°C, holding for 7 h + temperature 466°C, holding for 23 h, forging at a temperature of 400°C, quenching from a temperature of 475°C and a two-stage aging regime: temperature 120°C, holding for 6 h + temperature 135°C, holding for 7 h (Application U.S. No. 2003/219353).

The disadvantages of these methods are the heterogeneity of the structure of semi-finished products, low fracture toughness K1C, significant anisotropy of mechanical properties and reduced corrosion properties, which leads to reduction of lifetime and reliability of the products.

The closest to the proposed method adopted for the prototype, is a method of manufacturing extruded semi-finished products from aluminum alloy and products derived from them, including the casting of ingots, annealing at a temperature 320-395°C hot pressing, heat treatment in the solid solution at a temperature of 430-S, quenching and aging.

The disadvantage of this method is that the method is specialized for manufacturing power parts of the airframe of the aircraft and does not satisfy the technological requirements of mass production of thin-walled, long, hollow panels and pros who she is, used in the construction of railway carriages, and do not guarantee their stability properties, and cost little competitive.

The present invention is to develop a cost-effective method of manufacturing pressed, long, thin-walled, hollow panel width up to 790 mm and profiles designed for railway transport with complex structural, technological and operational properties that meet future requirements in this area of engineering.

The technical result achieved when applying the proposed method, is the creation of competitive production technology of high-alloy aluminum alloy system Al-Zn-Mg-Cu-Zr semi-finished products, in which good mechanical, technological and corrosion properties of the products are provided with optimal thermo-mechanical processing.

This technical result is achieved in that in the method of extruded semifinished products from high strength aluminum alloy, including the casting of ingots, hot pressing, heat treatment for solid solution hardening and aging, characterized in that the ingots cast from an alloy having the following ratio of components, wt.%:

Zinc 3,6-4,1

Magnesium 0,6-1,1

Manganese 0,2-0,5

Zirconium 0,05-0,12

XP is m 0,05-0,15

Copper is 0.1-0.2

Titanium 0,01-0,06

Molybdenum 0,01-0,06

Aluminum else,

when the temperature of the casting 690-710°C with a speed of 25-50 mm/min is subjected to homogenization at a temperature of 450-470°C for 8-12 hours, hot pressing is carried out at a temperature 410-530°C at a rate of expiration of 0.1-4.0 m/min, quenching produce temperature deformation immediately after pressing on the press, on the air or air-to-water mixture and two-step aging regime: temperature of 90-110°C, holding for 6-12 h + temperature of 160-190°C, holding for 4-10 hours

In case of considerable thickness in the cross section of the profile quenching products produced water after heating in an oven temperature of 450°C.

Even the natural aging for at least 7 days.

Products obtained in this way are made of long, thin-walled panels and profiles are intended for use on railway transport.

The choice of aluminum alloy, the chemical composition is due to the fact that in the process of smelting a large ingot of this alloy does not form intermetallic compounds of Al3Zr crystallization of origin, and the presence in the alloy of copper and distributed transition metals Cr, Mo, Ti, and the adjustment mode two-stage aging allowed us to obtain high resistance rockaways the th corrosion (3 points) and corrosion under tension at a high level of mechanical properties.

The mechanical properties of the alloy significantly exceed the mechanical properties of alloys of the type AD31 applied to manufacture cars abroad, and very close to the properties of the alloy 1915, passenger cars of which more than thirty years in operation in Russia.

Modes casting at a temperature of 690-710°C and the speed of the wheels 25-50 mm/min is chosen empirically and provide a uniform alloy structure throughout the volume of the ingot.

The structure of the alloy to be hardened on the press begins when carrying out the homogenization annealing of cast ingots. During aging at a temperature of homogenization is the dissolution of the coarse particles of excess Mg2Si phase formed during crystallization of the melt at the eutectic reaction and segregated at the grain boundaries and dendritic branches. By the end of the exposure of Mg2Si particles in the structure of the ingot is practically absent, and the magnesium and silicon are solid aluminum solution. The homogenization of the ingot is carried out at a temperature of 450-470°C for 8-12 hours, the excess of these limits leads to a separation along the grain boundaries of fusible elements, homogenization at lower settings does not guarantee acceptable alignment of chemical microheterogeneity of beans.

The formation of a solid solution of the main alloying components in aluminum in the alloy is going on is it when the temperature is much easier and faster than, for example, in the alloy AD31, which is alloyed with silicon, due to the easy and rapid dissolution of particles η (MgZns) relative to the particles of Mg2Si (phase Mg2Si is one of the most thermally stable phases, which form the main alloying components in industrial aluminum alloys (Cu, Mg, Zn, Si) and aluminum).

Thus, this alloy has a high stability of the supersaturated solid solution of the main alloying components (zinc and magnesium) in aluminum, the temperature interval of the reduced stability of the solid solution is displaced into the region of low temperatures, and the temperature of the pressing coincides with the temperature interval of existence of solid solution of zinc and magnesium in aluminum, which is very wide (340-615°C). These features provide a good opportunity for hardening press moldable semi-finished products.

The attractiveness of low temperature extrusion is that it achieves high surface quality of the extruded semi-finished product and reduces the probability of formation of internal delamination.

Pressing at a temperature of pressing is lower than the temperature 410°C is not rational, because of increasing efforts pressing, pressing at temperatures above 530°C leads to lower quality products.

The flow rate varies within the Ah of 0.1-4.0 m/min and depends on the size and configuration of the sections of the product, in particular, during the extrusion of complex thin-walled hollow panels or profiles to reduce the effort of pressing the heating temperature can be increased to 500-530°C. the Pressing of such a complex semi-finished products is carried out with a reduced speed of expiration, and eye-catching deformation heat has time to leave the tool. In this case, the magnitude of the temperature increase is small.

Due to the fact that the temperature interval of existence of solid solution in the alloy has a very wide range (340-615°C), for fixing the solid solution during the extrusion of thin-walled panels and profiles are sufficient cooling air or water-air mixture, which allows you to perform this operation immediately after pressing on the press table.

In the manufacture of monolithic profiles with significant cross-sectional area is quenching in water, the temperature of 450°C, after heating in the furnace, which ensures uniformity of properties throughout the volume of the product.

Manufactured from this alloy can be used as in the naturally aged condition, and after artificial aging. Strength properties in the naturally aged condition after the long months of aging even slightly higher than after artificial aging, however, extruded semi-finished products in the naturally aged is able to be more sensitive to dissecting corrosion. Therefore, when choosing a state of semi-finished product for the specific operating conditions should be guided by the choice of the optimum combination of strength and corrosion resistance.

Artificial two-stage aging regime: temperature of 90-110°C, holding for 6-12 h + temperature of 160-190°C, holding for 4-10 hours On the first level there is an intensive formation of zones of Genie-Preston, who at the second stage are the germ of the education of strengthening particles phase η (MgZn2). In the particles made with high density in a unit volume of the matrix and the maximum strengthen the alloy. When perestiani is minimal loss of strength properties.

The temperature of the second step of aging the alloy was selected 160-190°C. the reason for this choice was the fact that at lower temperature with increasing duration of exposure, as shown by preliminary experiments, no appreciable growth resistance dissecting corrosion. A small temperature increase of the second stage up to 200°C leads to a strong decrease of the strength characteristics. The optimal time drawing on the first and second stage, in which, with minimal degradation of properties was achieved maximize resistance dissecting corrosion, were chosen empirically.

The invention is illustrated in f is cografiya, which shows cross-sections:

Figure 1 - profile (dimensions 350×110 mm);

Figure 2 - panel (dimensions 790×52 mm);

Figure 3 - panel cipher (dimensions 790×50 mm).

Figure 4 (a-d - svetlopoli image, e - dark-field image in the reflex phase of Al3Zr, and- ×500×2; 6 - ×5800×2; g - ×48000×2; e, f - 36000×2)

An example of a specific implementation.

In the electric furnace of the resistance type SAN with a capacity of 10 tons were performed 2 melting the following chemical composition, table 1:

Table 1
The number of meltMass fraction of elements,%
CuMgMnFeSiCrZnTiMoZr
10,1170,8310,2960,1900,0672of 0.0813,800,02750,01080,088
2to 0.1270,8710,3090,1650,05140,06434,070,02650,02020,103

Then were cast slabs and billets. Casting ingots was carried out in the following modes table 2:

Table 2
The number of meltThe size of the ingot mmSettings casting
temperature, °Cspeed, mm/minThe water pressure, PA
1310×111070546,6of 1.4×105
2051070026,74,558×104

Modes of homogenization cast ingots are shown in table 3.

Table 3
The size of the ingot mmThe temperature of homogenization, °CThe duration of exposure, h
310×1110455-46012
0510460-46312

From cast ingots were made an experimental batch of 2 types of panels (2 and 3) and type 1 profiles (figure 1). Quenching profiles were carried out in water after soaking in a vertical quenching furnace temperature of 450°C. Tempering panels were held on the table of the press temperature deformation by forced air. Modes pressing are shown in table 4.

Table 4
The temperature of the workpiece, °CThe temperature of the matrix, °CThe temperature of the container, °CThe outflow velocity, m/minThe amount of permanent deformation when the edit %Artificial ageing
I stepLevel II
410-530 360-460410-4500,1-4,0-a 0.11,0-3,5100°C 6-12 h170-180°C 4-10 h

Mechanical properties of extruded semi-finished products in the naturally aged and artificially aged condition on the selected mode (100°C, 10 h +175°C, 6 hours) are given in table 5 and 6.

15,9
Table 5
Profile properties
StateDirectionσinMPaσ02MPaδ, %ψ, %
Naturally agedLongitudinal34723614,321,8
Cross36926413,233,5
Artificially aged at 100°C, 10 h+175°C, 6 hLongitudinal30924338,9
Cross33327515,254,3

Table 6
Properties panel (longitudinal sample)
Place tenderloin sampleStateσinMPaσ02MPaδ, %DGC Score
Canvas panelNaturally aged35321920,08,5
Artificially aged at 100°C, 104+175°C, 6432225218,93
PartitionNaturally aged35021719,0-
Artificially aged 10°C, 104+175°C, 6433225318,3-

Properties of specimens cut from the partition panel (table 6), not inferior properties of the samples cut from the fabric panel and are characterized by rather high values. This confirms that the alloy when processed in this way has a very high stability of the solid solution, which allows its fixation at low speed cooling from high temperatures.

As in the case of the profile properties pane in the naturally aged condition is slightly higher properties in the artificially aged condition. However, resistance dissecting corrosion, as shown by the test panel, much better than in the artificially aged condition. After natural aging tendency of the panels to dissecting corrosion is estimated 7-8 points, and after artificial aging - 3 points.

Figure 4 presents the results of electron microscopic studies of the structure of the profile in the state of delivery. At low magnification in the electron microscope visible subgrain structure (figa, b), and at higher magnification clearly distinguished particle inter-intermetallic compounds of transition metals manganese, chromium (pigv), erchonia (figd, e). On Figg shows the boundary subzero, pent-up intermetallic compounds of manganese (type Al6Mn) and zirconium (Al3Zr).

After quenching extruded semi-finished products are guaranteed to remain fully precrystallization structure.

Non-crystalline (polygoncount) structure in extruded semi-finished products ensures a high level of complex service performance. First of all, it improved strength properties with good ductility, high impact strength and higher resistance to corrosion under stress.

High structural and technological properties of the products made by this method were confirmed by testing of welded joints. Weld extruded profiles SP after 60 days of natural aging after welding has σinSt=255 MPa, bend angle =77 degrees, XIseam=28 j/cm2, Vseam=21 j/cm2, KCV zones of fusion =38 j/cm2. The study of the weldability of extruded profiles of alloy In 1935 showed that the alloy has a low tendency to cracking during welding, and the attenuation coefficient of the welded connection is 0,80-0,95; welded joints and the joints of plastic and viscous. Welded joints have high resistance to stress corrosion in natural iskusstvenno aged conditions. The propensity for dissecting corrosion of welded joints is estimated 7-8 score in the naturally aged condition and 2-3 points after artificial aging.

The proposed method is extrusion of semi-finished products of high strength aluminum alloy provides a unique, long, thin-walled profiles and panel width up to 790 mm, intended for use on railway vehicles, having a set of structural, technological and operational properties that meet future requirements in this area of engineering.

1. A method of manufacturing extruded semi-finished products of high strength aluminum alloy, including the casting of ingots, hot pressing, heat treatment for solid solution hardening and aging, characterized in that the ingots cast from an alloy having the following ratio of components, wt.%:

Zinc3,6-4,1
Magnesium0,6-1,1
Manganese0,2-0,5
Zirconia0,05-0,12
Chrome0,05-0,15
Copper 0,1-0,2
Titanium0,01-0,06
Molybdenum0,01-0,06
AluminumThe rest,

when the temperature of the casting 690-710°C, with a speed of 25-50 mm/min, the ingots are subjected to homogenization at a temperature of 450-470°C for 8-12 h, the hot pressing is carried out at a temperature 410-530°C at a rate of expiration of 0.1-4.0 m/min, quenching produce temperature deformation immediately after pressing on the press in air, in water or in air-to-water mixture and implement natural aging or artificial aging for a two-step mode: the temperature of 90-110°C exposure 6-12 h, the temperature of 160-190°C, holding for 4-10 hours

2. The method according to claim 1, characterized in that the hardening produce water from a temperature of 450°C.

3. The method according to claim 1, characterized in that produce natural aging for at least 7 days.

4. The product obtained from semi-finished products of high strength aluminum alloy, characterized in that it is obtained from a semi-finished product manufactured by the method according to any one of claims 1 to 3.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: alloy contains, wt %: 3.5-4.5 zinc, 3.5-4.5 magnesium, 0.6-1.0 copper, 2.0-3.0 nickel, 0.25-0.3 zirconium, aluminium - balance, at the same time after strengthening thermal treatment the alloy has yield point of 570 MPa, strength limit of 600 MPa, hardness of 160 HY, and after deformation at 440-480°C with speed of 0.001-0.01 1/s the alloy has elongation of more than 500%.

EFFECT: production of alloy with equiaxial homogeneous fine-grain structure.

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EFFECT: high strength and precision.

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EFFECT: application of the proposed technology will make it possible to produce rolled semi-finished products with improved operating properties, due to production of a fine-grain recrystallised structure and isotropy of properties.

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SUBSTANCE: proposed composition contains the following substances, in wt %: zinc - 5.0-5.8, magnesium - 1.1-1.2, chromium - 0.2-0.3, copper - 0.1-0.4, titanium - 0.05-0.15, cerium - 0.005-0.05, samarium - 0.005-0.05, silicon - not over 0.3, iron - not over 0.3, zirconium - not over 0.005, aluminium making the rest. Method of making semis from said aluminium alloy comprises first thermal treatment at up to 480°C, cooling to room temperature, and second thermal treatment at up to 200°C.

EFFECT: higher strength, lower residual strain.

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EFFECT: high strength, low sensitivity to quenching.

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EFFECT: improving armour properties and durability of sandwich plate.

5 cl, 1 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to alloy of AA7000 series and to the manufacturing method of products from this aluminium alloy, and namely to aluminium deformed products of relatively large thickness, namely of 30 to 300 mm. Method involves casting of workpiece - ingot of aluminium alloy of AA7000 series, which contains >0.12 to 0.35% Si, pre-heating and/or homogenisation of workpiece, hot deformation treatment of workpiece using one or more methods chosen from the group, which involves rolling, extrusion and forging, optionally cold deformation treatment, solution treatment, workpiece solution treatment cooling, optional tension or compression or other cold deformation treatment for release of stresses, which is performed by straightening or drawing or by cold rolling, ageing of workpiece in order to achieve the required state. At least one heat treatment is performed at temperature in the range of more than 500°C, but lower than solidus temperature of the considered aluminium alloy. The above heat treatment is performed either: (i) after heat treatment by homogenisation prior to hot deformation treatment, or (ii) after solution treatment, or (iii) both after heat treatment by homogenisation prior to hot deformation treatment, and after solution treatment.

EFFECT: obtaining the product from deformed aluminium alloy, which has improved balance of properties, and namely destruction viscosity, tensile yield point, tensile ultimate strength and relative elongation.

30 cl, 8 tbl, 3 ex

FIELD: metallurgy.

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where T corresponds to instant temperature in K during annealing, while Tcontr corresponds to control temperature equal to 302°F (423K), and t(eq) is expressed in hours.

EFFECT: production of deformed product possessing improved combination of mechanical strength for corresponding level of crack resistance and resistance to corrosion cracking under load.

8 cl, 2 dwg, 10 tbl, 4 ex

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SUBSTANCE: product consists of following components, wt %: Zn 9.0-14.0, Mg 1.0-5.0, Cu 0.03-0.25, Fe <0.30, Si <0.25, Zr from 0.04 to less, than 0.3 and one or more elements chosen from group consisting of: Ti <0.30, Hf <0.30, Mn <0.80, Cr <0.40, V <0.40 and Sc <0.70, random elements and impurities, each <0.05, totally <0.15, and aluminium - the rest. The procedure for fabrication of product out of aluminium alloy consists in casting an ingot, in homogenisation and/or in preliminary heating the ingot upon casting, in hot treatment of the ingot into preliminary finished product with one or more methods, chosen from the group including rolling, extrusion and forging. Not necessarily, the preliminary treated product can be heated or hot treated and/or cold treated to a required shape of a blank; further formed blank is subjected to heat treatment to solid solution, to hardening blank heat treated to solid solution; not necessarily, hardened blank can be stretched or compressed, or cold treated by other way to stress relief, for example, by levelling sheet products or artificial ageing, till obtaining a required condition.

EFFECT: product with reduced tendency to forming hot cracks and with improved characteristics of strength, fracture toughness and hardness over 180 HB at artificially aged state.

32 cl, 6 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: method involves ingot casting with the following composition, wt %: Zn 6.0 - 11.0, Cu 1.4 - 2.2, Mg 1.4 - 2.4, Zr 0.05 - 0.15, Ti <0.05, Hf and/or V <0.25, optionally Sc and/or Ce 0.05 - 0.25%, optionally Mn 0.05 0.12%, and inevitable impurities and aluminium is the rest, homogenisation and/or pre-heating of ingot after casting, hot deformation processing of ingot so that pre-processed product is obtained, heating of pre-processed product and either hot rolling of heated product to final thickness, or hot rolling and cold rolling of heated product to final thickness, heat treatment for solid solution and hardening of heat-treated product for solid solution, optional tension or compression of hardened product and optional ageing of hardened and optionally tensed or compressed product to the desired state; at that, rolled product at its final state has in fact fully non-recrystallised microstructure at least in position T/10.

EFFECT: product has increased yield point at compression and high specific energy of crack propagation, and improved viscosity and corrosion resistance properties.

21 cl, 6 tbl, 3 ex

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SUBSTANCE: alloy contains, wt %: 3.5-4.5 zinc, 3.5-4.5 magnesium, 0.6-1.0 copper, 2.0-3.0 nickel, 0.25-0.3 zirconium, aluminium - balance, at the same time after strengthening thermal treatment the alloy has yield point of 570 MPa, strength limit of 600 MPa, hardness of 160 HY, and after deformation at 440-480°C with speed of 0.001-0.01 1/s the alloy has elongation of more than 500%.

EFFECT: production of alloy with equiaxial homogeneous fine-grain structure.

4 ex

FIELD: metallurgy.

SUBSTANCE: alloy contains the following, wt %: silicon 6.6-7.4, magnesium 0.31-0.45, copper 0.18-0.32, manganese 0.15-0.45, iron 0.15-0.4, aluminium is the rest, at that, the alloy has liquidus temperature within 608 to 620°C; temperature of balanced solidus of not less than 552°C and structure after heat treatment as per mode T66, which contains the amount of inclusions of silicon phase within 6.4 to 7.5 vol. %; iron in the alloy structure is completely bound to skeletal inclusions of phase Al15(Fe,Mn)3Si2, and magnesium is completely bound to secondary extractions of phase Al15Cu2Mg8Si6.

EFFECT: creation of alloy for obtaining high-duty shaped castings and having high technological and operating characteristics.

2 cl, 2 tbl, 2 ex, 2 dwg

FIELD: metallurgy.

SUBSTANCE: proposed composition contains the following substances, in wt %: zinc - 5.0-5.8, magnesium - 1.1-1.2, chromium - 0.2-0.3, copper - 0.1-0.4, titanium - 0.05-0.15, cerium - 0.005-0.05, samarium - 0.005-0.05, silicon - not over 0.3, iron - not over 0.3, zirconium - not over 0.005, aluminium making the rest. Method of making semis from said aluminium alloy comprises first thermal treatment at up to 480°C, cooling to room temperature, and second thermal treatment at up to 200°C.

EFFECT: higher strength, lower residual strain.

11 cl, 4 ex

FIELD: metallurgy.

SUBSTANCE: invention may be used for making critical parts operated at high loads at 150°C, e.g, those of aircraft, cars and trucks, etc. Proposed composition contains the following substances, in wt %: 5.5-6.5 Zn, 1.7-2.3 Mg, 0.4-0.7 Ni, 0.3-0.7 Fe, 0.02-0.25 Zr, 0.05-0.3 Cu. Its solvus temperature does not exceed 410°C while hardness makes, at least 150 HV.

EFFECT: higher strength and machinability.

3 cl, 3 tbl, 3 ex, 2 dwg

FIELD: metallurgy.

SUBSTANCE: proposed composition contains the following substances, in wt %: zinc - 4-5, indium - 0.01-0.1, zirconium - 0.01-0.1, titanium - 0.02-0.1, aluminium and impurities making the rest. Content of impurities in the alloy of iron, silicon and copper may no exceed 0.1, 0.1 and 0.01, respectively, while that of hydrogen must no exceed 0.20 cm3/100 g Me.

EFFECT: higher efficiency and stability of electrochemical characteristics.

2 cl, 3 tbl

FIELD: metallurgy.

SUBSTANCE: invention may be used for making critical parts operated at high loads at 100-150°C, e.g, those of aircraft, cars and trucks, etc. Aluminium-based alloy comprises 7-12% of Zn, 2-5% of Ca, 2.2-3.8% of Mg, 0.02-0.25% of Zr. Note here that its hardness makes at least 150 HV, σB>450 MPa. σ0.2>400 MPa.

EFFECT: new high-strength alloy for thermal hardening, making shaped castings.

4 tbl, 3 ex, 2 dwg

FIELD: metallurgy.

SUBSTANCE: ingot, at least, 4in-thick, is made from aluminium-based alloy containing, at least, 6.5 wt % of zinc and magnesium at zinc-to-magnesium ratio of 5:1. Said ingot features, at quarter of thickness, the tensile strength of, at least, 61 kgft/sq.in and yield points of, at least, 54.5 kgft/sq.in. Proposed method comprises the following stages: 12 in-thick ingot is cast from aluminium-based alloy containing: 6-8 wt % of Zn, 1-2 wt % of Mg, with Mg content making (0.2 × Zn - 0.3) wt %-(0.2 × Zn + 0.3) wt %, at least, one element forming intermetallic dispersoids, aluminium and unavoidable impurities making the rest. Then, ingot is homogenised at 820°F to 980°F, and cooled by one of below methods: forced feed of air, water mist and water spray. Then, it is artificially aged at 240°F to 320°F to allow age-hardening.

EFFECT: high strength, low sensitivity to quenching.

12 cl, 8 dwg, 6 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy of light alloys, particularly, to super strong heat-treatable aluminium alloys of Al-Zn-Mg-Cu system intended for making semis, i.e. formed and rolled tubes, stamped covers to be used as has centrifuge parts. Articles are made from alloy containing the following components in wt %: zinc 8.0-9.0, magnesium 2.3-3.0, copper 2.0-2.6, zirconium 0.1-0.2, beryllium 0.0001-0.002, cerium 0.005-0.05, calcium 0.005-0.05, titanium 0.005-0.05, iron up to 0.15, silicon up to 0.1, and at least of element of the group: manganese up to 0.1, aluminium making the rest.

EFFECT: higher strength, ductility, toughness, fatigue strength.

2 cl, 2 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: plate from aluminium alloy consists of 6.8-8.5 wt % Zn, 1.75-2.3 wt % Cu, 1.5-1.84 wt % Mg and up to 0.25 wt % at least of one of Zr, Hf, Sc, Mn and V, and if necessary, additives crushing the grain, and the rest includes aluminium and inevitable impurities; at that, plate has the thickness of not more than 2.00 inches. Plate has the ratio between yield strength and failure viscosity, which meets the following equation: FT_LT ≥ -4.0* (TYS_L)+453. Plate has TYS_L that is at least 80 ksi and FT_LT that is at least 100 ksi√ inch, where TYS_L - tensile yield strength of the plate in direction L, in ksi, which is measured in compliance with ASTM E8 and ASTM B557, FT_LT - failure viscosity (Kapp) of the plate in flat stressed state in direction L-T, in ksi√inch, which is measured in compliance with ASTM E561 and B646 on specimen of aluminium alloy with central crack in position T/2 of the plate; at that, specimen has the width of 16 inches, thickness of 0.25 inches and initial length of preliminary fatigue crack of 4 inches.

EFFECT: plates are made from aluminium alloys having high failure viscosity at maintaining the acceptable strength level.

32 cl, 10 dwg, 10 tbl, 4 ex

FIELD: weapons and ammunition.

SUBSTANCE: method consists in obtaining the workpiece to be rolled and its heating, hot rolling of plate according to the size requirements, cooling down to room temperature and artificial ageing. Production of workpieces to be rolled involves rolling according to the size requirements of ingots and/or slabs from aluminium alloys for sandwich plate and assembly of a pack using them. Pack is heated at 500-550°C during 5-7 hours. Rolling according to the size requirements is performed at 410-450°C. Additional hardening is performed at 450-480°C. Artificial ageing is performed at temperature of 110-120°C during 24-36 hours.

EFFECT: improving armour properties and durability of sandwich plate.

5 cl, 1 tbl

FIELD: metallurgy.

SUBSTANCE: aluminum based protective alloy comprises, in mass %, 4-5 of zinc, 0.01-0.06 of indium, 0.01-0.1 solder, 0.01-0.1 of zirconium, and aluminum the remainder.

EFFECT: enhanced corrosion protection.

2 tbl

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