High-strength aluminium-based alloy and method for obtaining items from it
SUBSTANCE: group of inventions can be used at manufacture of semi-finished products in the form of forgings, formings, pressed rods and channels, rolled plates and sheets from high-strength alloys of Al-Zn-Mg-Cu system, which are intended to be used in power structures of aerospace equipment and transport means, on which stringent strength, crack resistance, fatigue life, corrosion resistance requirements are imposed. In order to solve the set task, high-strength alloy on the basis of aluminium, which contains the following, wt %, is proposed: Zn 6.2-8.0, Mg 1.5-2.5, Cu 0.8-1.2, Zr 0.05-0.15, Fe 0.03-0.15, Ti 0.01-0.06, at least one element of the group of metals: Ag 0.01-0.5, Sc 0.01-0.35, Ca 0.0001-0.01, Al and inevitable impurities are the rest. In particular version of alloy the inevitable impurities include not more than 0.05 of Si, Mn, Cr, Ni and not more than 0.01 of Na, H2, O2, B, P. Method for obtaining an item from this alloy involves ingot casting, its homogenisation, hot deformation and strengthening heat treatment of the item, which includes hardening and staged ageing; at that, during the ingot casting there performed is melt purification by blowing with argon or mixture of argon with chlorine and out-of-furnace purification using rotor and/or filtering devices, and homogenisation is performed as per one-stage mode at temperature which is by 55-130°C lower than unbalanced solidus (tu.s.) temperature of this alloy with exposure during 8-36 h or as per two-stage mode at temperature at the first stage at the temperature which is by 175-280°C lower than tu.s. temperature, and at the second stage at the temperature which is by 75-125°C lower than tu.s., with exposure at each stage to 24-36 h; hot deformation is performed at temperature of 300-420°C, hardening is performed at temperature which is by 50-120°C lower than tu.s. during the time determined with the item thickness, with further cooling to temperature of not more than 80°C.
EFFECT: improving the set of mechanical and corrosive characteristics, and characteristics of crack resistance, life time and manufacturability.
10 cl, 1 tbl
The invention relates to metallurgy and can be used in the manufacture of semi-finished products in the form of forgings, die forgings, extruded rods and profiles, rolled plates and sheets of high-strength alloys of the system Al-Zn-Mg-Cu intended for use in the power structures of aerospace equipment and vehicles that require extreme strength, fracture toughness, fatigue life, corrosion resistance.
Known for high strength aluminum alloy of the following composition, % wt.: Zn 7,0-11,0; Mg 1,8-3,0; Cu 1,2-2,6; at least one element from the group of Mn (0,05-0,4), Cr (0,05-0,3), Zr (0,05-0,2), Hf (0,05-0,3), V (0,05-0,3), Ti (0.01 to 0.2) and Sc (0,05-0,3), the rest is aluminum and inevitable impurities, and the product made from it by casting an ingot from the specified alloy, followed by homogenization of the ingot, hot deformation of the specified ingot by rolling, extrusion or forging, hardening, possible stretch marks with the degree of residual deformation 1-5%, the aging of the product under such temperature and time of exposure, which provide a shared direction maximum yield strength in compression, for example two-stage aging regime 80-120°C, holding for 24 h + 135-150°C, holding 7-30 h or a three-stage aging treatment as 100°C, holding for 24 h + 140-160°C, holding for 2.5 to 18 h + 120°C, holding for 24 h (Patent EP No. 1231290).
The disadvantage of the Plava and products made from it, are the low values of fracture toughness and corrosion characteristics, as well as the high rate of growth of fatigue cracks, which limits its use in high-efficiency critical structures.
Also known wrought aluminum alloy of the following composition, % wt.: Zn 6,2; of 2.5 Mg; Cu 1,8; Zr 0,13; Fe 0,11; Si<0,09; else Al. The method of manufacturing of products includes the following operations: the casting of ingots semi-continuous method, the homogenization of the ingot at temperatures 300-448°C, exposure to 3 h, cooled to a temperature of 25°C with a speed of 150-300°C/h, heating to a temperature of 250°C, holding for 10 h, forging ingot (50% of the original length of the drawing) at a temperature of 250°C, heating the forged billet to a temperature of 365°C, holding for 8 h, rolling at a temperature of 365°C. with a deformation rate of 64%. Thermal treatment of the product: tempering temperature of 470°C, holding for 5 h, cooling in water with a temperature of 45°C and a two-stage artificial aging: temperature 1st stage 110°C, holding for 8 h, temperature 2nd stage 170°C, holding for 10 h (RF Patent 2087582).
The disadvantage of this alloy and products derived from it, is the low strength properties, fracture toughness, low resource operation and corrosion resistance.
The closest in technical essence, accepted for p is totip, is the alloy system Al-Zn-Mg-Cu of the following composition, % wt.: Zn 5,7-8,7; Mg of 1.7-2.5; Cu 1,2-2,2; Zr 0.05 to 0.15; Fe 0,07-0,14; Si<0,11; Mn<0,02; Cr<0,02; Mg+Cu<4,1; the rest of Al and impurities <0,05 each and <in the amount of 0.10. A product made from it in the form of rolled, forged and extruded semi-finished products for power elements mainly wing aircraft produced by the casting of the ingot and its homogenization at a temperature of 465°C, hot deformation, hardening heat treatment - quenching from a temperature of 480°C in cold water, dressing with the degree of residual strain of 2% and a subsequent aging treatment as 115°C, 6 h + 172°C, 10 h (U.S. Patent No. 6027582).
The disadvantage of this alloy and products derived from it, the specified method are the low values of strength and corrosion characteristics and fracture toughness, which leads to low resource work products, as well as the high level of residual quenching stresses, causing subsequent machining significant leashes and warping in the details, which increases the complexity of the manufacturing process and increase the percentage of marriage. In addition, the chemical composition of this product does not allow you make of it welded structure.
Technical problem, the present invention is the creation of high-strength aluminum alloy system Al-Zn-Mg-Cu and method of manufacture of products from negatives is in the form of forgings, forgings, extruded profiles, rods, plates and sheets with improved complex mechanical properties, fracture toughness, the crack growth rate and fatigue and corrosion characteristics, and low in 2-3 times the level of residual quenching stresses and improved processability during the welding process.
To solve the problem proposed high-strength alloy based on aluminum, including Zn, Mg, Cu, Zr, Fe, which additionally contains Ti and at least one element from the group of metals Ag, Sc, Ca, with the following ratio of components, wt.%:
Mg 1.5 to 2.5
Zr 0.05 to 0.15
at least one element from the group of metals
Sc from 0.01 to 0.35
Ca is 0.0001 to 0.01
the rest is aluminum and inevitable impurities.
The inevitable impurities in the alloy includes Si, Mn, Cr, Ni not more than 0.05 each and Na, H2About2In, P less than 0.01 each.
The method of obtaining the products of this alloy comprises casting an ingot, its homogenization, hot deformation and hardening heat treatment including quenching and speed aging, while in the process of casting ingot spend refining of the melt by blowing argon or a gas mixture of argon and chlorine, and secondary refining using a rotary and/or filtering devices, homogenization is performed in dostupan the atom mode when the temperature 55-130°C below the temperature of the nonequilibrium solidus (t NS) aged 8-36 hours or a two-step mode when the temperature of the first stage on 175-280°C below the temperature tNSaluminum alloy, and the second stage at 75-125°C below tNSexposure time at each step up to 24-36 h, the hot deformation is carried out at a temperature of 300-420°C, quenching is carried out at a temperature of 50-120°C below tNSduring the time defined by the thickness of the product, followed by cooling to a temperature not higher than 80°C.
Cooling during hardening is carried out in water at a temperature of 15-80°C or in an aqueous solution of an organic polymer.
The way in which the aging is conducted for a two-step mode - 1st stage at a temperature of 105-120°C, holding for 5-24 h, 2nd stage at a temperature of 160-185°C, holding for 3-15 hours
The way in which the aging is carried out on the three-mode - 1st stage at a temperature of 90-140°C, holding for 5-24 h, 2nd stage at a temperature of 150-175°C exposure 3-12 h, 3-stage at a temperature of 90-140°C, holding for 5-24 hours
The way in which the aging is carried out on the three-mode - 1st stage at a temperature of 120-140°C, holding for 8-24 h, 2nd stage at a temperature of 20-90°C aging for at least 24 h, 3-stage at a temperature of 120-155°C, holding for 8-24 hours
The product of the specified high-strength aluminum alloy made in the form of deformed semi-finished product: forgings, stampout is, extruded or rod, rolled plate or sheet.
The product may be in the form of weld design strength of welded connection to 0.8 on the strength of the base metal.
Two-mode aging achieves the most high-level characteristics of the fracture toughness (K1Cand SRTO) and corrosion resistance with medium strength 530-550 MPa. There are two options, the three-mode aging provide products with a high level of strength and resource characteristics. The product has a tensile strength (tensile strength) tensile to 530-700 MPa. Products have large dimensions of thickness, width and length: the size of the cross-section is pressed up to a width of 1000 mm, thickness up to 260 mm, punchings - width up to 450 mm, plate and sheet length up to 30000 mm
Examples of carrying out the invention
1. Alloy composition: Zn 6,2%, Mg of 1.9%, Cu 1,0%, Zr of 0.11%, Fe 0,09%Ti, 0.03%, the Ca of 0.001%, impurity Si of 0.05%, Mn 0.01%, In 0,003%, H20,00002% were cast into the melting-casting machine with vacuum mixer with magnezitovoj non-wetted by liquid aluminum lining, and ropinirole by blowing a gas mixture of Ar+5%Cl. In the casting of the ingot to improve the purity of the metal used filtered through ceramic foam filters with a mesh size of 40 pores per inch, and secondary refining in stroebe by mounting the rotary type. In the melt introduced the ligature of the Al-Ti-B alloy modifying and grinding grain. The ingot is homogenized in a two-step mode: the temperature of the 1st stage at 280°C below tNS(tNS=577°C), exposure 24 h, temperature 2nd stage 125°C below tNSextract , 10 o'clock Homogenized ingot was subjected to hot deformation - first by free forging at tDef.=400-410°C with the degree of 65%, and then closed die three transition - blanking stamping, finishing, stamping and final forging in the temperature range 330-390°C.
The result has been a product in the form of punching thickness of 155 mm Heat treatment forging was carried out according to the following regime: heating to a temperature of hardening at 120°C below tNSextract , 240 min, cooling in a solution of organic polymer to reduce the hardening stress, aging for a three mode: 1-St stage 120°C, holding for 16 h, 2nd stage 160°C, holding for 3 h, 3-stage at a temperature of 140°C, holding for 12 h Produced by the above method, the stamping had the properties shown in table 1.
2. Alloy composition: Zn 8.0%, and Mg to 1.5%, Cu 0,8%, Zr of 0.05%, Fe of 0.03%, Ti of 0.01%, Ag Of 0.25%, Sc Of 0.2%, Ca 0,0001% of the rest of Al and impurities Si, Mn<0,05% each, N2<0,000027% and<0,001%, P<0,0001% were cast into the melting-casting unit-resistant lining with electricalconnection. For refining melting and removal of oxide captivity and hydrogen content were performed using a purge gas mixture of argon +5% chlorine and filtered through panoramiczne filters with cell 40 pores per inch, as well as through the mesh with a cell size of 0.6×0.6 mm For grinding grain structure of the ingot melt mixer modified by ligature of the Al-Ti-B. the resulting ingot with a diameter of 650 mm and homogenized in a two-step mode: the 1st step within 24 hours at a temperature aging at 175°C below tNS(tNS=526°C)2nd stage within 24 hours at a temperature of 55°C below tNS. Then after turning the surface of the ingot was subjected to induction heating to a temperature of 400-420°C and deformed by the pressing of a direct method with a drawing ratio of 12.8 to obtain a rectangular profile thickness of 200 mm, the Specified profile is subjected to hardening regime: heating to a temperature of 50°C below tNS, the exposure time of 120 min, cooled in cold water (T=28°C) and then edit the tensile test at room temperature with the degree of residual deformation of 2.2% for removing residual quenching stresses. The ageing profile was carried out on the three-step regime: temperature : 115°C, dwell time 16 hours + 170°C, hold time 5 h + 90°C, the exposure time 24 hours
The result has been a product in the form of a profile. Made about the Ile had complex properties, shown in table 1. In addition, the resulting profile has increased manufacturability during welding, and the strength of weld σswaet.was ≥0,7-0,8 σosnet.
3. Alloy composition: Zn 6,9%, Mg of 2.5%Cu and 1.2%, Zr of 0.15%, Fe of 0.15%, Ti 0,04%, Ca 0,01%, Si 0,06%, Mn 0.01%, In 0,003%, H20,00002% were cast as in example 1. The ingot is homogenized for one mode at a temperature of 130°C below tNS°C (tNS=577°C), the shutter 36 PM Homogenized ingot was subjected to forging in the 3rd diagram (three precipitation and three broaches) with three heatings and with the degree of deformation at each transition 60-65% at tDef.=360-400°C. Heat treatment forging was carried out according to the following mode: heated to the quenching temperature is 100°C below tNSextract , 5 h, cooled in cold water (tin=22°C). After 2 h after quenching the forgings were subjected to cold deformation by compression with the degree of residual deformation of 3% to reduce the hardening stress, aging was conducted for a two-step mode: 1-St stage 115°C, holding for 16 h, 2nd level 175°C endurance 5 hours
The result has been a product in the form of forgings. Manufactured forgings had the properties shown in table 1.
4. Alloy composition: Zn 7,1%, Mg of 2.2%, si of 1.1%, Zr of 0.12%, Fe of 0.10%, Ti 0,06%, Ca 0,001%, Si 0,06%, Mn 0.01%, In 0,003%, N20,00002% were cast as in example 1. The ingot cross-section of 300×1200 mm g who was multiserial for a two-step mode: the temperature of the 1st stage at 230°C below t NS(tNS=577°C), exposure 24 h, temperature 2nd stage 110°C below tNSextract , 8 hours Homogenized ingot was heated to a temperature rolling and 400°C. and subjected to hot deformation for 10 passes.
The result has been a product in the form of a plate thickness 60 mm Thermal processing plate was carried out in the following mode: heated to the quenching temperature to 105°C below tNSextract , 5 h, cooled in cold water (tin=30°C). After 1 h after quenching the plate was subjected to cold deformation by stretching with the degree of residual strain of 2.5% to reduce the hardening stress, aging was performed according to the three-step regime: 1-St stage - 120°C, holding for 24 h, 2nd level - 65°C, holding for 48 h, 3-I stage - 145°C, holding for 10 hours Made stove had the properties shown in table 1.
Table 1 presents the complex properties of the products obtained from the alloy proposed by the applicant in comparison with the properties of products made from alloys proposed in the patents and analog prototype.
It is established that the application of the proposed composition of the alloy and the method of manufacturing of the products ensures obtaining the desired improved complex mechanical and corrosion properties, fracture toughness characteristics, resource and technology.
The desired combination of properties is achieved C is by increasing the purity of the metal impurities of hydrogen and non-metallic inclusions due to the blowing of the melt by a gas mixture of Ar+Cl, as well as enhanced cleaning through ceramic foam filters in combination with secondary refining rotary device. Obtaining high purity metal in combination with the proposed mode of homogenization of the ingot, providing the structure with the minimum volume fraction of primary particles of eutectic phase and homogeneous distribution of the secondary dispersed particles (aluminides of transition metals Zr, Sc, Mn, and others), improves the characteristics of the fracture toughness (K1CSRTU) and resource (MCU) compared to the prototype. The alloy contains no environmentally harmful components, such as Be.
Significant difficulties in the machining of forgings, die forgings of alloy Al-Zn-Mg-Cu arise due to significant distortion of parts due to the high level of residual quenching stresses. In the proposed invention this disadvantage is eliminated by reducing the residual quenching stresses more than 3 times by stretching or compression of the product at room temperature in svezhenanesennom condition with a residual deformation of 1-5%. A similar effect is achieved when used as a medium for cooling during quenching of hot water (temperature up to 80°C) or an aqueous solution of an organic polymer, which slows down the cooling rate of the product during hardening and reduced residual voltage is the first and the leash in the product.
Mode aging also provides, on the one hand, the selection on the grain boundaries of fine particles stable strengthening phase MgZn2on the other hand, creates a homogeneous metastable hardening precipitates in the body of the grain and in the border zone. The structure of the product contributes to a significant increase in strength (σin, σof 0.2) and corrosion characteristics (K1SCC- fracture toughness in a corrosive environment and RAC - penchant for dissecting corrosion), and also improves the durability of the product during fatigue loads (MCO).
The manufacturing of the alloy containing microadditives Ag and Sc, which can significantly improve its manufacturability during welding, providing strength of the weld at the level of 0.7-0.8 times the strength of the base metal, which allows to produce products in the form of welded structures, in contrast to the products of the prototype, which is not welded.
Thus, application of the present invention allows to obtain products for power structures and aerospace engineering and vehicles with improved complex mechanical and corrosion properties, fracture toughness characteristics, resource and technology.
1. High-strength aluminum alloy comprising Zn, Mg, Cu, Zr, Fe, characterized in that the stage is niteline contains Ti and
at least one element from the group of metals Ag, Sc, Ca in the following ratio, wt.%:
|Mg||1.5 to 2.5|
at least one element from the group of metals
|Ca||of 0.0001 to 0.01|
|Al and inevitable impurities||rest|
2. High-strength aluminum alloy according to claim 1, wherein the inevitable impurities include Si, Mn, Cr, Ni not more than 0.05 each and Na, N2O2In, P less than 0.01 each.
3. The product of high strength aluminum alloy, characterized in that it is made from an alloy according to claim 1 or 2.
4. The product according to claim 3, characterized in that it is made in the form of forgings, stamping, molded Pro is I or rod, rolled plate or sheet.
5. The product according to claim 3, characterized in that it is made in the form of welded construction with the strength of a welded joint to 0.8 on the strength of high-strength aluminum alloy.
6. The way to obtain products of high strength aluminum alloy, including the casting of the ingot, its homogenization, hot deformation and hardening heat treatment of the product by quenching and speed of aging, characterized in that the cast ingot of a high-strength alloy according to claim 1, wherein in the process of casting ingot spend refining of the melt by blowing it with argon or argon with chlorine and secondary refining using a rotary and/or filtering devices, and the homogenization is performed in single-stage mode at a temperature of at 55-130°C below the temperature of the nonequilibrium solidus (tNS) alloy according to claim 1 aged 8-36 hours or a two-step mode when the temperature of the first stage on 175-280°C below the temperature tNSand in the second stage on 75-125°C below tN.S.exposure time at each step up to 24-36 h, the hot deformation is carried out at a temperature of 300-420°C, quenching is carried out at a temperature of 50-120°C below tN.S.during the time defined by the thickness of the resulting product, followed by cooling to a temperature not higher than 80°C.
7. The method according to claim 6, distinguish the different topics what cooling during hardening is carried out in water at a temperature of 15-80°C or in an aqueous solution of an organic polymer.
8. The method according to claim 6, wherein the aging is conducted for a two-step mode: 1 stage at a temperature of 105-120°C, holding for 5-24 h, 2nd level at a temperature of 160-185°C, holding for 3-15 hours
9. The method according to claim 6, wherein the aging is carried out on a three mode: 1 stage at a temperature of 90-140°C, holding for 5-24 h, 2nd level at a temperature of 150-175°C exposure 3-12 h, 3-stage at a temperature of 90-140°C, holding for 5-24 hours
10. The method according to claim 6, wherein the aging is carried out on a three mode: 1 stage at a temperature of 120-140°C, holding for 8-24 h, 2nd level at a temperature of 20-90°C, holding for at least 24 h, 3-stage at a temperature of 120-155°C, holding for 8-24 hours
SUBSTANCE: manufacturing method of solid constructional element welded by forging method from aluminium alloy involves hot pressure shaping stage, at least one cold pressure shaping stage by means of plastic deformation, at which at least two zones of the above constructional element are subject to average consolidated plastic deformations differing at least by 2% and preferably differing at least by 3%. If necessary, after cold pressure shaping there performed is cutting, machining and/or shaping of constructional element welded by means of forging method.
EFFECT: manufacture of constructional elements, including those not subject to tempering, having variable operating properties in the space and rather economic geometrical characteristics identical to characteristics of known elements.
26 cl, 5 dwg, 12 tbl, 4 ex
SUBSTANCE: procedure for ageing parts of high precision instruments out of quenched alloy AK8M consists in two-stage ageing and cooling in air. The first stage of ageing is performed during 1.5 hours at temperature 140±5°C, while the second stage is performed during 3 hours at temperature 170±5°C.
EFFECT: raised strength without reduction of plasticity; upgraded reliability of parts.
1 tbl, 1 ex
FIELD: process engineering.
SUBSTANCE: invention relates to metal forming and may be used in hot die forging of articles from, primarily, aluminium-magnesium alloys. Workpiece is heated to 240…260°C with isothermal curing at said temperature for 0.5…2 h. Then, die forging is performed at the rate of 5·10-3…5·10-2 s-1 in molds heated to 350…400°C.
EFFECT: improved mechanical properties, higher quality of die forging.
1 tbl, 1 ex
SUBSTANCE: there is proposed manufacturing method of thin-wall parts from aluminium wrought alloys, which involves manufacture of workpieces by forming, which is close as to the shape and dimensions to dimensions of finishing part with minimum allowances for mechanical processing, preliminary machining by removing the metal from outer cold-worked layers and in the places which are concentrators of maximum inner stresses, and stabilising heat treatment. Then cyclic treatment is performed, which involves machining operations so that the installation and fixing of the processed part is provided on the equipment without changing its curvature, which are performed in turn with the operations of stabilising heat treatment; after that, final machining is performed with further natural ageing of the finished part in the forced state.
EFFECT: minimising deformation of thin-wall parts from aluminium wrought alloys, which appears at their manufacture by machining with metal removal.
3 cl, 2 dwg, 1 tbl
SUBSTANCE: thermal treatment procedure is designed to decrease or prevent bubble formation. There is produced a casting by high pressure die-casting procedure causing gas or other internal porosity in the casting. The casting is made out of dispersed-solidifying aluminium alloy containing from 4.5 to 20 wt % Si, from 0.05 to 5.5 wt % Cu, from 0.1 to 2.5 wt % Fe, from 0.01 to 1.5 wt % Mg, not necessarily - at least one from Ni up to 1.5 wt %, Mn up to 1 wt % and Zn up to 3.5 wt %, and aluminium and unintentional impurities - the rest. The following stages of heat treatment are carried out to decrease or prevent formation of bubbles in a casting. The casting(a) is heated to and within an interval of temperature of treatment to solid solution wherein soluble elements are transited to solid solution. Heating is carried out (i) to and within the interval 20-150°C below temperature of solidus for casting alloy and (ii) during less, than 30 minutes. Further, the casting is cooled (b) starting from an interval of temperature at stage (a) by quenching the casting in a liquid quenching medium at temperature between 0°C and 100°C. Ageing (c) of a quenched casting from stage (b) is performed in the interval of temperature of natural or artificial ageing from 0°C to 250°C, thus producing a casting which has been subjected to solidification or hardening.
EFFECT: production of castings with decreased bubble formation or without bubbles, also structure elements made out of these castings maintain dimension uniformity and possess improved mechanical properties.
20 cl, 32 dwg, 17 tbl
SUBSTANCE: disclosed here invention refers to thermal treatment and can be implemented at tempering thin section casts of complex shape for successive fabrication of high precision parts out of them. The procedure consists in heating to 535°C and holding during 4 hours, in cooling with a furnace at rate 90-110°C per hour to 420°C, in conditioning for 1 minute, in cooling in water at temperature 90-100°C, in holding for 3 minutes and in cooling in water at temperature 20-30°C.
EFFECT: reduced deformation of casts at tempering and ageing and increased reliability and service life of casts.
SUBSTANCE: prior to heat treatment welded structure is positioned into facility consisting of case in form of steel pipe with plates arranged on its ends. One of the plates is stationary, while another travels along axis of the facility. Wedge hold-down devices are mounted on the plates; locating blocks with removable stops are installed in an interval between the plates; there is a setting gap between the removable stops. Present deformations and deviations from geometric shape are corrected by means of screw and wedge hold down devices and also with locating blocks and plates. Upon fixation of specified dimensions and shape of the structure the facility with the structure is placed in a furnace, is heated to temperature 350°C and conditioned during 0.5 hour. Then heating is terminated and the structure is removed from the furnace, when temperature drops to 150°C.
EFFECT: removing internal stresses in welded structure and maintaining its geometric shape.
2 cl, 2 dwg
SUBSTANCE: here is disclosed procedure for thermal treatment of cast items or work pieces out of silumin AK7. The procedure consists in heating, conditioning and successive cooling. A work piece is heated and conditioned at temperature (0.4-0.7) teut. °C, where teut. °C is temperature of eutectic transformation of alloy, while successive cooling to temperature -10 -(-20) °C is performed at simultaneous effect of gas flow and acoustic field of sound range of frequencies with level of sound pressure within 140-160 dB. Grains are crumbled and intra-granular structure is formed where dislocation are built as ordered formations; micro-stresses are decreased at boundaries of phases division.
EFFECT: upgraded mechanical properties.
5 cl, 1 dwg, 1 tbl, 1 ex
SUBSTANCE: procedure for thermal treatment of item out of aluminium alloy consists in stages whereat item is subject to heat treatment for solid solution, to tempering, and to heating tempered item by preliminary ageing at stage of heat treatment. Heat treatment by preliminary ageing is carried out at conjugating base surface of the item with base surface of a heating plate. Preliminary ageing treatment is performed outside furnace. The item out of aluminium alloy and the heating plate are conjugated by placing a protective layer between the item out of aluminium alloy and the heating plate. The protective layer is made out of insulating material chosen from a group including glass-cloth, ceramic, glass wool, mineral cotton and woven and not woven polymer material. Also here are disclosed the heating plate and the facility for implementation of heat treatment by preliminary ageing.
EFFECT: production of dispersed-strengthened aluminium alloy with properties required for its implementation.
26 cl, 7 dwg
SUBSTANCE: invention refers to manufacture of hollow items from aluminium alloys. Method involves fabrication of a hollow semi-finished product and heat treatment - ageing for the alloys strengthened with heat treatment, or annealing for the alloys non-strengthened with heat treatment. Heat treatment is performed in the device for heat fixing of external and/or internal surfaces of semi-finished product throughout its whole length or some part of length; at that, at heat fixing of external semi-finished product surface, as the device there used is sleeve made from steel with low thermal linear expansion coefficient with functional sleeve diametre calculated by the formula DS≈D[1+(αa-αs)·tH-αa·αs·t2 H], where DS-functional sleeve diametre at normal temperature, D - outer diametre of semi-finished product at normal temperature, αa - thermal linear expansion coefficient of aluminium alloy, αs thermal linear expansion coefficient of steel from which sleeve is made, tH - heating temperature of semi-finished product and sleeve at final heat treatment (°C). At thermal fixing of inner surface of semi-finished product, as the device there used is mandrel made from material with thermal linear expansion coefficient close to thermal linear expansion coefficient of semi-finished product metal with functional mandrel diametre calculated by the formula d ≤ dm ≤ (d + 0.5 · Δd) , where d - inner diametre of semi-finished product at normal temperature, dm - functional mandrel diametre at normal temperature, Δd - allowance for inner semi-finished product diametre.
EFFECT: improving geometric relationship of hollow items from aluminium alloys of any geometric shape.
2 dwg, 2 ex
SUBSTANCE: invention refers to alloys on base of aluminium, particularly to Al-Zn-Cu-Mg alloys on base of aluminium, and also to procedure of fabrication of rolled or forged deformed product of it and to rolled or forged deformed product proper. The procedure consists in following stages: a) casting an ingot, containing wt % Zn 6.6-7.0, Mg 1.68-1.8, Cu 1.7-2.0, Fe 0-0.13, Si 0-0.10, Ti 0-0.06, Zr 0.06-0.13, Cr 0-0.04, Mn 0-0.04, additives and other side elements ≤0.05 each, b) homogenising of the said ingot at 860-930°F or, preferably, at 875-905°F, c) hot deformation treatment of the said ingot with temperature at input 640-825°F, but preferably - 650-805°F by rolling or forging to a plate with finish thickness from 2 to 10 inches, d) thermal treatment for solid solution and quenching the said plate, e) drawing the said plate with residual deformation from 1 to 4 %, f) ageing the said plate by heating at 230-250°F during from 5 to 12 hours and 300-360°F during from 5 to 30 hours during equivalent time t(eq) between 31 and 56 hours. Equivalent time t(eq) is determined from formula:
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
SUBSTANCE: alloy on base of aluminium contains following components wt %: zinc 5-8, magnesium 2-3.1, nickel 1-4.2, iron 0.02-1, zirconium 0.02-0.25 %, copper 0.05-0.3 %. Also, temperature of equilibrium solidus of material is as high as 550°C and hardness is as high as 180 HV. Alloy has a structure corresponding to matrix formed with solid solution of aluminium with uniformly distributed disperse particles of secondary discharges in it and particles of aluminides containing nickel and iron of eutectic origin uniformly distributed in matrix. Also, alloy contains matrix and aluminides at the following ratio, vol % aluminides containing nickel and iron 5.0-6.3, matrix - the rest.
EFFECT: production of new high-strength alloy thermally hardenable and designed both for fabrication of shaped casting and of deformed semi-products.
4 cl, 5 tbl, 4 ex
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
SUBSTANCE: invention refers to deformed alloys of aluminium-zinc-magnesium-scandium system and to procedure for their production. Aluminium alloy contains from 0.5 to 10 wt % Zn, from 0.1 to 10 wt % Mg, from 0.01 to 2 wt % Sc, at least 0.01 wt % at least one alloying additive chosen from Ag at amount of up to 1 wt % and Sn at amount of up to 0.5 wt %, aluminium and unavoidable additives - the rest. The procedure consists in production of the said aluminium alloy, in homogenisation, in extrusion, in treatment for solid solution, in quenching, in straightening with drawing and in ageing.
EFFECT: alloys possess good qualities such as relatively high strength and excellent corrosion resistance.
33 cl, 3 dwg, 4 tbl
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
SUBSTANCE: aluminium-based alloy contains the following, wt %: zinc 0.5-0.7; titanium 0.1-0.13; silver 1.1-1.3; nickel 0.25-0.5; copper 0.15-0.25; cobalt 0.7-0.9; aluminium - the rest.
EFFECT: alloy is characterised with increased strength.
1 tbl, 3 ex
SUBSTANCE: invention refers to metallurgy of protecting alloys on base of aluminium and can be implemented at production of protectors for aluminium heat exchangers on airplanes, sea and river vessels, domestic heaters and also fuselages of hydroplanes and vessels out of aluminium alloys for protection from corrosion. Protecting deformed alloy on aluminium base contains following components, wt %: zinc 1.8-3.0, magnesium 0.4-0.8, silicon 0.3-0.6, tin 0.03-0.07, indium 0.06-0.07, aluminium - the rest.
EFFECT: production of protecting alloy possessing upgraded mechanical properties which facilitates fabrication of protectors of various shape, small dimensions and big length.
2 tbl, 1 ex
SUBSTANCE: invention refers to deformed thermally hardened high-tensile aluminium alloys Al-Zn-Mg-Cu designed for fabrication of all kinds of deformed semi-finished products, including thin sheets used in aircraft and machine engineering and other branches of industry. Deformed alloy on base of aluminium and an item out of it contain the following components, wt %: zinc 2.5-4.0, magnesium 4.1-6.5, copper 0.2-1.0, iron to 0.25, silicon to 0.15, scandium 0.005-0.3, zirconium 0.005-0.25, nickel and/or cobalt to 0.1, titanium to 0.15, boron and/or carbon to 0.05, at least one element out of group: hafnium to 0.15, molybdenum to 0.15, cerium to 0.15, manganese to 0.5, chromium to 0.28, yttrium to 0.15, vanadium to 0.15, niobium to 0.15, aluminium and unavoidable impurities - the rest, also ratio of Mg contents to Zn contents is more or equal to 1.1.
EFFECT: production of alloy and items out of it possessing raised strength properties at simultaneous increased wear-resistance, reduced rate of crack growth, increased durability of welded connections and reduced density, which results in increased resource and reliability of items operation and in reduced weight of structures.
3 cl, 2 tbl, 1 ex
SUBSTANCE: invention refers to metallurgy, particularly to aluminium-based alloys which can be applied in dishware and coin production. Aluminium-based alloy contains, wt %: zinc 1.3-1.8; titanium 0.01-0.015; silver 1.3-1.8; nickel 1.3-1.8; cobalt 1.3-1.8; indium 0.2-0.3; the rest is aluminium.
EFFECT: production of alloy of enhanced hardness.
SUBSTANCE: particularly it concerns alloys on aluminium basis, which can be used in automotive industry. Aluminium-based alloy contains the following components, wt %: zinc 2.0-2.5; antimony 0.01-0.015; titanium 0.01-0.015; boron 0.007-0.009; beryllium 0.001-0.002; cobalt 0.6-0.9; the rest is aluminium.
EFFECT: production of alloy of enhanced hardness.
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.