Procedure for thermal treatment of items out of high strength aluminium alloys

FIELD: metallurgy.

SUBSTANCE: procedure for the thermal treatment of items out of high strength aluminium alloys of a system Al - Zn - Mg - Cu, containing in wt %: zinc 6.0-9.0, magnesium 1.6-2.6, copper 0.8-1.6, zirconium 0.07-0.15, iron 0.02-0.15, silicon below 0.1, aluminium and inevitable admixtures - the rest, includes hardening and artificial ageing, contains the stages of isothermal and non-isothermal ageing. First of all, the first stage of isothermal ageing is performed at a temperature of 60-90°C for 10-24 h, then the first stage of non-isothermal ageing is performed by means of the item heating to 160-195°C with the rate of 10-15°C/h, then the second stage of isothermal ageing at a temperature of 160-195°C is performed during the time period determined from the relationship t=ln(473/T)/0.009, where t is the holding time, h, T is the holding temperature, K, and the second stage of non-isothermal ageing is performed by cooling from 160-195°C to 80°C with the rate determined by the equation V=ln(T/88.5)/0.0057, where V is the cooling rate, K/h, T is the holding temperature, K.

EFFECT: reduced sensitivity to laminating, intergranular and pitting corrosion, increased homogeneity of the structure and properties in the item volume, producing the items with improved strength and corrosion characteristics, including for marine conditions operation.

3 cl, 2 tbl, 1 ex

 



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: method to produce axisymmetric forgings of a cover type with a diameter of up to 200 mm from high-strength aluminium alloys Al-Zn-Mg-Cu, alloyed with scandium and zirconium, includes preparation of aluminium melt, containing scandium and zirconium, its reheating to 765-780°C, casting of round bars of small diameter at 710-740°C, their homogenisation at 400-440°C for 4-10 hours, stamping at 380-440°C, tempering from temperature 465-480°C with even cooling of the entire surface of forgings with speed providing for preservation of fully non-crystallised structure of the forging after tempering, and artificial ageing.

EFFECT: forgings have lower level of residual tempering stresses, which provides for stability of geometric parameters of parts due to elimination of ovalisation when turning forgings into thin-walled parts.

2 tbl, 1 ex

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

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.

4 ex

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, particularly, to production of thin-wall pipes. Proposed method comprises forming and piercing of solid ingot in container insert by its needle, press ring plate and press ram, as well as quenching, straightening and artificial ageing. Prior to forming with piercing, ingot arranged in said contained is compacted by cupped blank arranged between said ring plate and ram at the needle with aligned ends of the needle and ring plate, and is removed after compaction. Note here that straightening of quenched tube is performed by gaging the tube OD to the rate of deformation of 0.5-2.5.

EFFECT: high strength and precision.

1 dwg, 1 tbl

FIELD: metallurgy.

SUBSTANCE: method includes homogenisation of a bar, heating to 360-450°C, hot rolling, cold rolling with extent of deformation of 45-70% and intermediate annealing, and final thermal treatment, including three-stage artificial ageing according to the following mode: first stage at 80-125°C for 8- 24 hr, second stage at 130-180°C for 4-30 hr and third stage at 145-180°C for 2-18 hr or double-stage ageing, including the first and second, or the second or third, or the first or third stages.

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.

3 cl, 5 ex, 8 tbl, 1 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: 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: 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: 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.

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

FIELD: metallurgy.

SUBSTANCE: invention relates to high-alloyed superhard alloys based on aluminium of Al-Zn-Mg-Cu system to be used as a structural material in aircraft engineering and rocketry, surface vehicles and instrument making. This alloy and article made thereof contain the following components, wt %: zinc - 8.5-9.3, magnesium - 1.6-2.1, copper - 1.3-1.8, zirconium - 0.06-0.14, manganese - 0.01-0.1, iron - 0.02-0.10, silicon - 0.01-0.05, chromium - 0.01-0.05, beryllium - 0.0001-0.005, hydrogen - 0.8·10-5-2.7·10-5 and at least one of elements of the group including titanium - 0.02-0.06, boron - 0.001-0.01, aluminium making the rest. Total content of zinc, magnesium and copper may not exceed 12.5-13.0%. Total content of transition metals, i.e. zirconium, manganese and chromium may not exceed 0.25-0.30%. Iron-to-silicon should make at least 1.5.

EFFECT: higher strength and crack resistance.

5 cl, 2 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: alloy contains in wt %: zinc 8-10, magnesium 2.0-3.0, copper 1.6-2.6, scandium 0.12-0.25, zirconium 0.06-0.20, beryllium 0.0001-0.005, cobalt 0.05-0.15, nickel 0.5-1.0, iron 0.45-0.95, aluminium - rest, at that ratio between zinc and magnesium is within range 3.1-4.1.

EFFECT: increased alloy strength at room temperature, and creep resistance at moderately increased temperatures.

3 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: alloy contains the following, wt %: zinc - 4.0-6.0, manganese - 0.1-0.3, magnesium - 0.5-2.5, titanium - 0.01-0.1, calcium - 0.005-0.01, aluminium is the rest at the following limitation of content of impurities: iron is not more than 0.1, copper is not more than 0.01, silicone is not more than 0.1, hydrogen is not more than 0.35 cm3/100g of metal.

EFFECT: providing high electrochemical characteristics and excluding a risk of passivation of surface of cast protectors made from the proposed alloy; increasing tensile strength limit of an alloy.

1 tbl

FIELD: metallurgy.

SUBSTANCE: welded aluminium alloy contains, by wt %: zinc 3.8-5.3; magnesium 1.2-2.0; manganese 0.91-1.3; chrome 0.12-0.40; zirconium 0.07-0.15; copper 0.10-0.30; iron ≤ 0.35; silicium ≤ 0.35; vanadium 0.01-0.12; boron 0.01-0.12; nickel ≤ 0.05; calcium ≤ 0.05; aluminium - the rest, at the total contents of zinc and magnesium 5.0-7.3 by wt % and the ratio between the contents of zinc and magnesium - 1.90-4.58.

EFFECT: creation of welded aluminium alloy for the armoured skin, which provides at a high corrosion stability of the armoured skin, increase of safe level increase of resistance to formation of back chips.

1 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to constructional elements from aluminium alloy, in particular, for space industry. The slab is made with the thickness at least 4 inches from aluminium alloy, which contains (wt %): Zn - from 6.4 up to 8.5, Mg - from 1.4 up to 1.9, Cu - from 1.4 up to 1.85, Zr - from 0.05 up to 0.15, Ti - from 0.01 up to 0.06, Fe - up to 0.15, Si - up to 0.12, the rest is aluminium, accompanying elements and impurities.

EFFECT: improved combination of durability and resistance to fracturing is provided, and also the resistance to a fracturing as a result of stress corrosion is provided, especially in conditions of marine atmosphere.

10 cl, 14 dwg, 14 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: method to produce axisymmetric forgings of a cover type with a diameter of up to 200 mm from high-strength aluminium alloys Al-Zn-Mg-Cu, alloyed with scandium and zirconium, includes preparation of aluminium melt, containing scandium and zirconium, its reheating to 765-780°C, casting of round bars of small diameter at 710-740°C, their homogenisation at 400-440°C for 4-10 hours, stamping at 380-440°C, tempering from temperature 465-480°C with even cooling of the entire surface of forgings with speed providing for preservation of fully non-crystallised structure of the forging after tempering, and artificial ageing.

EFFECT: forgings have lower level of residual tempering stresses, which provides for stability of geometric parameters of parts due to elimination of ovalisation when turning forgings into thin-walled parts.

2 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed composition contains the following substances, in wt %: zinc - 6.0-8.0; magnesium - 3.4-4.2; copper - 0.8-1.3; scandium - 0.07-0.15; zirconium - 0.08-0.12; beryllium - 0.0005-0.004; cerium - 0.01-0.15; titanium - 0.02-0.08; silicon - 0.01-0.15; iron - 0.01-0.15; hydrogen - 0.05-0.35 cm3/100 g of metal; unavoidable impurities from the group including Mn, Cr, V, Mo, Li, Ag, K, Na, O in total amount of not over 0.10, aluminium making the rest at the ratio of magnesium-to-zinc content making 0.53-0.57.

EFFECT: higher strength of Al-Zn-Mg-Cu-system alloys and articles.

2 cl, 1 ex, 2 tbl

FIELD: electricity.

SUBSTANCE: invention refers to active material of negative electrode for electric device containing an alloy with composition formula SixZnyAlz, where each of x, y and z is mass percentage meeting the following: (1) x+y+z=100, (2) 26≤x≤47, (3) 18≤y≤44 and (4) 22≤z≤46. Also invention refers to electrical device and negative electrode for it.

EFFECT: providing active material of negative electrode for electrical device such as lithium-ion accumulator battery providing well-balanced properties of high cycling conservation and high initial capacity.

4 cl, 2 tbl, 10 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: 50-305 mm-thick article is made from alloy of the following chemical composition, in wt %: Zn - 3-11, Mg - 1-3, Cu - 0.9-3, Ge - 0.03-0.4, Si - not over 0.5, Fe - not over 0.5, Ti - not over 0.3, aluminium and common or unavoidable elements and impurities making the rest. Proposed method comprises slab casting, heating and/or annealing treatment of cast slab, slab hot treatment, optional cold treatment, heat processing to solid solution of slab (PSS), cooling of PSS slab, optional expansion or compression of cooled PSS slab or any other cold treatment of PSS slab to remove strain, ageing of cooled PSS slab to reach required state.

EFFECT: high hardness, ductility and lower sensitive to quenching.

20 cl, 2 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: aluminium-based alloy is used for production of strained semis as forgings and tubes for gas centrifuges, low-pressure compressors, vacuum molecular pumps and heavy-duty units operated at mildly increased temperatures. Proposed composition contains the following substances, in wt %: zinc - 6.6-7.4, magnesium - 3.2-4.0, copper - 0.8-1.4, scandium - 0.12-0.30, zirconium - 0.06-0.20, beryllium - 0.0001-0.005, cobalt - 0.05-0.15, nickel - 0.35-0.65, iron - 0.25-0.65, aluminium making - the rest.

EFFECT: higher strength at sufficient ductility and reduce density of alloy.

1 ex, 3 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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