EP4162089B1 - Use of products made from aluminium copper magnesium alloy that perform well at high temperature - Google Patents

Description

TECHNICAL AREA

The invention relates to the use of products made of aluminum-copper-magnesium alloys, intended to be used at high temperatures.

PRIOR ART

Certain aluminum alloys are commonly used for applications in which they have a high operating temperature, typically between 80 and 250 °C and generally between 100 and 200 °C, for example as a structural part or means of attachment to proximity to motors in the automotive or aerospace industry or as rotors or other air suction pump parts such as vacuum pumps.

These alloys require good mechanical performance at high temperatures. Good mechanical performance at high temperature means in particular, on the one hand, thermal stability, that is to say that the mechanical properties measured at room temperature are stable after long-term aging at the operating temperature, and on the other hand, on the other hand, hot performance, that is to say that the mechanical properties measured at high temperature (static mechanical properties, creep resistance) are high.

Among the alloys known for this type of application we can cite the AA2618 alloy which includes (% by weight):
Cu:1.9-2.7 Mg:1.3-1.8 Fe:0.9-1.3, Ni:0.9-1.2 Si:0.10-0.25 Ti:0, 04-0.10 which was used for the manufacture of Concorde.

The patent FR 2279852 offers an alloy with a reduced iron and nickel content of the following composition (% by weight):
Cu:1.8-3 Mg:1.2-2.7 Si<0.3 Fe:0.1-0.4 Ni + Co: 0.1 - 0.4 (Ni + Co)/Fe: 0 .9 - 1.3

The alloy may also contain Zr, Mn, Cr, V or Mo at contents less than 0.4%, and possibly Cd, In, Sn or Be at less than 0.2% each, Zn at less than 8% or Ag has less than 1%. With this alloy we obtain a significant improvement in the stress concentration factor K1c representative of the resistance to crack propagation.

• Cu: 2,0 - 3,0 Mg: 1,5 - 2,1 Mn: 0,3 - 0,7
• Fe<0,3 Ni<0,3 Ag<1,0 Zr<0,15 Ti<0,15
• avec Si tel que: 0,3 < Si + 0,4Ag < 0,6
• autres éléments < 0,05 chacun et < 0,15 au total.

The patent application EP 0 756 017 A1 relates to an aluminum alloy with high creep resistance of composition (% by weight):

• Cu: 2.0 - 3.0 Mg: 1.5 - 2.1 Mn: 0.3 - 0.7
• Fe<0.3 Ni<0.3 Ag<1.0 Zr<0.15 Ti<0.15
• with Si such that: 0.3 < Si + 0.4Ag < 0.6
• other elements < 0.05 each and < 0.15 total.

• Cu: 3,0 - 4,2 Mg: 1,0 - 2,2 Mn: 0,1 - 0,8 Zr : 0,03 - 0,2 Ti : 0,012 - 0,1, V : 0,001 - 0,15
• au moins un élément parmi Ni : 0,001 - 0,25 et Co : 0,001 - 0,25, reste aluminium.

The patent RU2210614C1 describes an alloy of composition (in % by weight):

• Cu: 3.0 - 4.2 Mg: 1.0 - 2.2 Mn: 0.1 - 0.8 Zr: 0.03 - 0.2 Ti: 0.012 - 0.1, V: 0.001 - 0, 15
• at least one element from Ni: 0.001 - 0.25 and Co: 0.001 - 0.25, remains aluminum.

The patent application WO2012/140337 concerns wrought products made of Al-Cu-Mg aluminum alloy of composition, in % by weight, Cu: 2.6 - 3.7; Mg: 1.5 - 2.6; Mn: 0.2 - 0.5; Zr: ≤ 0.16; Ti: 0.01 - 0.15; Cr ≤ 0.25; If ≤ 0.2; Fe ≤ 0.2; other elements < 0.05 and remaining aluminum; with Cu > - 0.9(Mg) + 4.3 and Cu < - 0.9 (Mg) + 5.0; where Cu = Cu - 0.74 (Mn - 0.2) - 2.28 Fe and Mg = Mg - 1.73 (Si - 0.05) for Si ≥ 0.05 and Mg = Mg for Si<0, 05 and their manufacturing process. The alloys mentioned in this application are particularly useful for applications in which the products are maintained at temperatures of 100°C to 200°C, typically around 150°C. The products mentioned in this application are useful for fastening parts intended for use in an automobile engine, such as screws or bolts or rivets or for the manufacture of nacelle parts and/or masts. aircraft hooking, the leading edges of aircraft wings and the fuselage of supersonic aircraft.

The patent application CN104164635 describes a method for improving the room temperature strength and high temperature performance of an Al-Cu-Mg alloy for an aluminum alloy drill pipe. The process includes the steps that the Al-Cu-Mg alloy is pre-stretched and deformed by 0-8% after solution processing, and then heated to 160°C to 190°C, for four hours to 120 hours , then, the alloy is taken out of a furnace, air cooling is carried out on the alloy and the ratio of copper to magnesium content in the Al-Cu-Mg alloy is less than or equal to five, the composition of the alloy being, in % by weight, Cu: 4.0% ~ 4.3%, Mg: 1.5% ~ 1.6%, Mn: 0.4% ~ 0.6%, Ti: 0.1% ~ 0.15%, rest Al.

The patent application CN107354413 relates to a technique for preparing high-strength heat-resistant aluminum alloy material for oil exploration, and belongs to the technical field of heat treatment of aluminum alloy. The alloy components are determined as Si <0.35, Fe <0.45, Cu 4.0-4.5, Mn 0.40-0.80, Mg 1.3-1.7, Zn < 0.10, Ti 0.08-0.20, Zr0.10-0.15 and other impurities 0.00-0.15.

The patent RU2278179 C1 relates to aluminum-copper-magnesium alloys useful as structural materials in airspace technology comprising (mass %) copper 3.8-5.5; magnesium 0.3-1.6; manganese 0.2-0.8; titanium 0.5.10 (-6) -0.07; tellurium 0.5.10 (-5) -0.01, at least one element from the silver-containing group 0.2-1.0; nickel 0.5.10 (-6) -0.05; zinc 0.5.10 (-6) -0.1; zirconium 0.05-0.3; chromium 0.05-0.3; iron 0.5.10 (-6) -0.15; silicon 0.5.10 (-6) -0.1; hydrogen 0.1.10 (-5) -2.7.10 (-5); and balance: aluminum.

The patent application WO2020074818 relates to a thin sheet of essentially recrystallized aluminum-based alloy with a thickness of between 0.25 and 12 mm comprising, in % by weight, Cu 3.4 - 4.0; Mg 0.5 - 0.8; Mn 0.1 - 0.7; Fe ≤ 0.15; If ≤ 0.15; Zr ≤ 0.04; Ag ≤ 0.65; Zn ≤ 0.5; unavoidable impurities ≤ 0.05 each and ≤ 0.15 in total; remains aluminum.

The patent application US2004013529 relates to a mechanical vacuum pump comprising a rotor made of a light metal alloy obtained by powder metallurgy. Powder metallurgy increases the rotor's resistance to heat and creep.

AA2219 alloy with composition (in % by weight) Cu: 5.8 - 6.8 Mn: 0.20 - 0.40 Ti: 0.02 - 0.10, Zr: 0.10 - 0.25 V : 0.05 - 0.15 Mg < 0.02 is also known for high temperature applications.

These alloys, however, have insufficient mechanical properties for certain applications and also pose recycling problems due in particular to the high content of iron and/or silicon and/or nickel and/or cobalt and/or vanadium.

We also know Al-Cu-Mg alloys, which are most often in the T3 state, an economical metallurgical state which does not require tempering heat treatment.

The patent US 3,826,688 teaches an alloy of composition (in % by weight), Cu: 2.9 - 3.7, Mg: 1.3 - 1.7 and Mn: 0.1 - 0.4.

The patent US 5,593,516 teaches an alloy of composition (in % by weight) Cu: 2.5 - 5.5, Mg: 0.1 - 2.3 within the limit of their solubility, that is to say such that Cu is at most equal at Cu _max = -0.91 (Mg) + 5.59.

The patent application EP 0 038 605 A1 teaches an alloy of composition (in % by weight), Cu: 3.8 - 4.4, Mg: 1.2 - 1.8 and Mn: 0.3 - 0.9, maximum 0.12 Si, 0 .15 Fe, 0.25 Zn, 0.15 Ti and 0.10 Cr.

The patent US 6,444,058 teaches a high purity AI-Mg-Cu alloy composition for which the effective values of Cu and Mg are defined, in particular by Cu _target = Cu _eff + 0.74 (Mn - 0.2) + 2.28 (Fe - 0.005) , and teaches a compositional domain in the Cu _eff : Mg _eff diagram in which the maximum value of Mg _eff is of the order of 1.4% by weight.

There is a need for aluminum alloy products having good mechanical performance at high temperatures, typically at 150°C, and being easy to manufacture and recycle.

STATEMENT OF THE INVENTION

• Cu : 3,6 - 4,4
• Mg: 1,2 - 1,4
• Mn : 0,5-0,8
• Zr: 0.07 - 0,15
• Ti : 0,01 - 0,05
• Si ≤ 0,20
• Fe ≤ 0,20
• Zn ≤ 0,25
• impuretés inévitables < 0,05
• reste aluminium,
• dans une application dans laquelle ledit produit est maintenu à des températures de 100 °C à 250 °C pendant une durée significative d'au moins 200 heures.

The object of the invention is the use of a product wrought in the T8 state in an aluminum alloy of composition, in % by weight,

• Cu: 3.6 - 4.4
• Mg: 1.2 - 1.4
• Min: 0.5-0.8
• Zr: 0.07 - 0.15
• Ti: 0.01 - 0.05
• If ≤ 0.20
• Fe ≤ 0.20
• Zn ≤ 0.25
• unavoidable impurities < 0.05
• remains aluminum,
• in an application in which said product is maintained at temperatures of 100°C to 250°C for a significant period of at least 200 hours.

FIGURES

[ Fig. 1 ] There Figure 1 shows the evolution of the breaking strength with the aging time at 150 °C in hours.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise stated, all indications regarding the chemical composition of alloys are expressed as a weight percentage based on the total weight of the alloy. The expression 1.4 Cu or 1.4 (Cu) means that the copper content expressed in % by weight is multiplied by 1.4. The designation of alloys is done in accordance with the regulations of The Aluminum Association, known to those skilled in the art. The definitions of metallurgical states are indicated in the European standard EN 515 - 2017. This standard indicates in particular that a T8 state: is a state put into solution, work hardened and then tempered, this designation applying to products which are subjected to work hardening for improve their mechanical strength, or for which the effect of work hardening associated with planing or straightening is reflected in the limits of mechanical properties. By T8 state we mean all the metallurgical states for which the first digit after T is 8. For example the T851 and T852 states are T8 states.

The static mechanical characteristics in traction, in other words the breaking strength R _m , the conventional elastic limit at 0.2% elongation R _p0.2 , and the elongation at break A%, are determined by a tensile test according to standard NF EN ISO 6892-1, the sampling and direction of the test being defined by standard EN 485-1. Hot tensile tests are carried out according to standard NF EN 10002-5. Creep tests are carried out according to standard ASTM E139-06. Unless otherwise stated, the definitions of EN 12258 apply.

The present inventors have noted that, surprisingly, there is a range of composition of Al-Cu-Mg alloys containing Mn which allows, when used in the T8 state, to obtain wrought products which are particularly efficient at high temperatures.

The magnesium content is such that Mg is between 1.2 and 1.4% by weight and preferably between 1.25 and 1.35% by weight. When the Mg content is not in the range according to the invention, the mechanical properties are not satisfactory. In particular, the breaking strength R _m may be insufficient at room temperature and/or after aging at 150°C.

The copper content is such that Cu is between 3.6 and 4.4% by weight. Advantageously Cu is at least 3.9% by weight and preferably at least 4.0% by weight. Advantageously Cu is at most 4.3% by weight and preferably at most 4.25% by weight.

The products intended for use according to the invention contain 0.5 to 0.8% by weight of manganese which contributes in particular to the control of the granular structure. Advantageously the Mn content is between 0.51 and 0.65% by weight. The present inventors have found that the simultaneous addition of manganese and zirconium can be advantageous in certain cases, in particular to reduce the sensitivity to aging at high temperatures while achieving high mechanical properties. The Zr content is a maximum of 0.15% by weight. The Zr content is at least equal to 0.07% by weight and preferably at least equal to 0.08% by weight. In an advantageous embodiment, the products intended for use according to the invention contain 0.09 to 0.15% by weight of zirconium and 0.50 to 0.60% by weight of manganese.

The titanium content is between 0.01 and 0.05% by weight. The addition of titanium contributes in particular to the refining of grains during casting. However, an addition greater than 0.05% by weight can result in excessively fine grain size which impairs creep resistance at elevated temperatures.

The iron and silicon contents are a maximum of 0.20% by weight each. In an advantageous embodiment of the invention, the iron content is a maximum of 0.18% by weight and preferably 0.15% by weight. In an advantageous embodiment of the invention, the silicon content is a maximum of 0.15% by weight and preferably 0.10% by weight.

The zinc content is a maximum of 0.25% by weight. In one embodiment of the invention, the zinc content is between 0.05 and 0.25% by weight and can contribute in particular to the mechanical resistance. However, the presence of zinc can pose recycling problems. In another embodiment, the zinc content is less than 0.20, preferably less than 0.15% by weight.

The content of the other elements is less than 0.05% by weight and preferably less than 0.04% by weight. Preferably, the total of the other elements is less than 0.15% by weight. The other elements are unavoidable impurities. The rest is aluminum.

The wrought products intended for use according to the invention are preferably sheets, profiles or forged products. The profiles are typically obtained by spinning. Forged products can be obtained by forging cast blocks or extruded products or rolled products.

The process for manufacturing the products intended for use according to the invention comprises the successive stages of preparing the alloy, casting, optionally homogenization, hot deformation, solution, quenching, cold deformation and tempering.

In a first step, a bath of liquid metal is produced so as to obtain an aluminum alloy of composition according to the invention. The liquid metal bath is then typically cast in the form of a rolling plate, spinning billet or forging blank.

Advantageously, the product thus cast is then homogenized so as to reach a temperature of between 450°C and 520°C and preferably between 495°C and 510°C for a period of between 5 and 60 hours. The homogenization treatment can be carried out in one or more stages.

The product is then hot deformed typically by rolling, spinning and/or forging. The hot deformation is carried out so as to preferably maintain a temperature of at least 300°C. Advantageously, a temperature of at least 350°C and preferably at least 380°C is maintained during hot deformation. No significant cold deformation is carried out, in particular by cold rolling, between hot deformation and solution application. Significant cold deformation is typically a deformation of at least about 5%.

The product thus deformed is then put into solution by a heat treatment making it possible to reach a temperature between 485 and 520 ° C and preferably between 495 and 510 ° C for 15 min to 8 h, then quenched.

The quality of the solution can be evaluated by calorimetry and/or optical microscopy.

The wrought product obtained, typically a sheet metal, a profile or a forged product, then undergoes cold deformation. Advantageously, the cold deformation is a deformation of 2 to 5% making it possible to improve the mechanical resistance and to obtain a T8 state after tempering. The cold deformation may in particular be a controlled tensile deformation leading to a T851 state or a compression deformation leading to a T852 state.

Finally, tempering is carried out in which the product reaches a temperature between 160 and 210°C and preferably between 175 and 195°C for 5 to 100 hours and preferably 10 to 50 hours. In an advantageous embodiment, tempering is carried out in which the product reaches a temperature of between 170 and 180°C for 10 to 15 hours. The income can be made in one or more stages. Preferably, the tempering conditions are determined so that the mechanical resistance Rp _0.2 is maximum (“peak” tempering). Tempering under the conditions according to the invention makes it possible in particular to improve the mechanical properties and their stability during aging at 150°C.

The thickness of the products intended for use according to the invention is advantageously between 6 mm and 300 mm, preferably between 10 and 200 mm. A sheet is a rolled product with a rectangular cross section and a uniform thickness. The thickness of the profiles is defined according to standard EN 2066:2001: the cross section is divided into elementary rectangles of dimensions A and B; A always being the largest dimension of the elementary rectangle and B can be considered as the thickness of the elementary rectangle.

The wrought products obtained according to the process have the advantage of having high mechanical strength and good performance at high temperatures. Thus the wrought products intended for use according to the invention preferably have in the longitudinal direction a breaking strength R _m of at least 490 MPa and preferably at least 495 MPa and having after aging at 150°C for 1000 hours, a breaking strength R _m of at least 475 MPa and preferably at least 480 MPa. The wrought products intended for use according to the invention are resistant to creep. Thus the wrought products intended for use according to the invention preferably have a duration necessary to reach a deformation of 0.35% during a creep test according to the ASTM E139-06 standard for a stress of 250 MPa and at a temperature of 150°C for at least 700 hours and preferably at least 800 hours.

The products intended for use according to the invention are particularly useful for applications in which the products are maintained at temperatures of 100°C to 250°C and preferably of 100°C to 200°C, typically at about 150°C. °C, for a significant duration of at least 200 hours and preferably at least 2000 hours.

Thus the products intended for use according to the invention are useful for applications of structural parts or means of attachment near the engine in the automobile industry or aerospace or preferably for applications of rotors or other parts in particular impellers of air suction pumps such as in particular vacuum pumps, such as in particular turbomolecular pumps or for applications of parts of air blowing devices such as impellers.

These and other aspects of the invention are explained in more detail using the following illustrative and non-limiting examples.

EXAMPLES Example 1

In this example 6 alloys were cast in the form of rolling plates. Alloy B has a composition according to the invention. Alloys C and E are taught by demand WO2012/140337 for their performance in high temperature uses. Alloy F is an AA2618 alloy, known for its performance in high temperature applications.

The composition of the alloys in % by weight is given in Table 1. <b>[Table 1]</b> Alloy If Fe Cu Mn Mg Neither Zn Ti Zr HAS 0.08 0.14 4.2 0.51 1.35 - 0.20 0.02 0.02 B (Invention) 0.04 0.07 4.0 0.58 1.40 - 0.12 0.02 0.10 C (Reference) 0.04 0.05 3.3 0.34 1.9 - - 0.02 0.11 D (Reference) 0.04 0.05 4.2 0.34 1.3 - - 0.02 0.11 E (Reference) 0.04 0.05 3.7 0.34 1.6 - - 0.02 0.11 F (Reference) 0.22 1.10 2.6 0.05 1.60 1.10 0.08 0.01 0.00

The plates were homogenized at a temperature between 490°C and 540°C, adapted depending on the alloy, hot rolled to a thickness of 10 mm (alloy A) and 15 mm (alloys B to E) and 21 mm (alloy F), put in solution at a temperature between 490 °C and 540 °C, adapted depending on the alloy, quenched in water by immersion, tensile from 2 to 4% and returned to 175 °C or 190 °C to reach the peak tensile yield strength in the state T8. Thus the alloy plates A and B were homogenized between 20 and 36 hours at 495°C, the sheets obtained after rolling being put in solution for 2 hours at 498°C and returned for 8 hours at 190°C or 12 hours at 175°C. The alloy C plate was homogenized in two stages of 10 hours at 500 °C then 20 hours at 509 °C, the sheet obtained after rolling being put in solution for 2 hours at 507 °C and returned for 12 hours at 190 °C. The alloy D plate was homogenized in two stages of 10 hours at 500 °C then 20 hours at 503 °C, the sheet obtained after rolling being put in solution for 2 hours at 500 °C and returned for 8 hours at 190 °C. The alloy E plate was homogenized in two stages of 10 hours at 500 °C then 20 hours at 503 °C, the sheet obtained after rolling being put in solution for 2 hours at 504 °C and returned for 12 hours at 190 °C.

The mechanical properties obtained at mid-thickness at 25°C in the longitudinal direction before and after aging are given in Table 2 in MPa. <b>[Table 2]</b> Alloy Income Property (MPa) Aging time (h) 0 1000 2000 3000 5000 10000 HAS 8h 190°C R _0.2 483 431 362 334 RM 511 480 440 417 B 8h 190°C R _0.2 459 421 394 351 RM 500 483 460 432 HAS 12h 175°C R _0.2 448 413 378 RM 490 474 452 B 12h 175°C R _0.2 416 394 353 RM 474 465 435 VS 12h 190°C R _0.2 456 447 436 421 RM 476 467 467 455 D 8h 190°C R _0.2 470 427 411 386 RM 483 472 463 449 E 12h 190°C R _0.2 468 462 440 424 RM 485 484 473 466 F R _0.2 420 406 387 355 RM 445 435 420 406

The evolution of the breaking strength with the aging time at 150 °C is represented on the Figure 1 . The products intended for use according to the invention have a breaking strength R _m greater than that of the reference products before aging and greater than most other alloys after 1000 hours at 150°C. After 3000 hours of aging, the products intended for use according to the invention have a mechanical resistance R _m greater than that of alloy F, which is an AA2618 alloy known for its high temperature properties.

Creep tests were carried out according to standard ASTM E139-06 for a stress of 285 MPa and at a temperature of 150 °C (alloys C, E and F) and for a stress of 250 MPa and at a temperature of 150 °C. C (alloys A, B and F) In particular, the time required to achieve a deformation of 0.35% was measured. The results are collected in Table 3. <b>[Table 3]</b> Alloy Stress (MPa) Direction L Time required to achieve a strain of 0.35% (h) Improvement factor compared to alloy F HAS 250 815 5.5 B 250 2100 14.1 F 250 149 - VS 285 221 3.6 E 285 267 4.4 F 285 61 -

The performance of the products intended for use according to the invention in the creep test is far superior to that of a reference product for uses at high temperatures (product F) and also superior to that of products C and E.

Example 2

In this example, we compared the evolution with the aging time at 150 °C of the elastic limit R _p0.2 for a rolled product in alloy B with a thickness of 10 mm obtained by the process as described in the Example 1, with a rolled product in alloy B with a thickness of 10 mm in the T351 condition. For the product in state T351, aging of 233 hours at 150°C is estimated using the data obtained after treatment for 8 hours at 190°C.

où T (en Kelvin) est la température instantanée de traitement du métal , qui évolue avec le temps t (en heures), et T_ref est une température de référence fixée à 423 K. t_i est exprimé en heures. La constante Q/R = 16400 K est dérivée de l'énergie d'activation pour la diffusion du Cu, pour laquelle la valeur Q = 136100 J/mol a été utilisée. Pour le produit à l'état T851, le vieillissement a été estimé pour 233 h par approximation linéaire à partir de la valeur de 426 MPa obtenue après 1000h.The equivalent time t _i at 150 °C is defined by formula 1: $${\mathrm{t}}_i=\frac{{\displaystyle \int \exp \left(-16400/\mathrm{T}\right)\mathrm{dt}}}{\exp \left(-16400/{\mathrm{T}}_{\mathrm{ref}}\right)}.$$

where T (in Kelvin) is the instantaneous metal treatment temperature, which changes with time t (in hours), and T _ref is a reference temperature fixed at 423 K. t _i is expressed in hours. The constant Q/R = 16400 K is derived from the activation energy for Cu diffusion, for which the value Q = 136100 J/mol was used. For the product in state T851, aging was estimated for 233 h by linear approximation from the value of 426 MPa obtained after 1000 h.

The results are presented in Table 4. <b>[Table 4]</b> R _p0.2 (TL) [MPa] Rp _0.2 (TL) [MPa] after aging at 150 °C Δ R _p0.2 [%] T351 349 459 32% T851 459 451 -2%

It can be seen that the thermal stability of the product in the T851 state is much greater than the thermal stability in the T351 state.

Claims (12)

1. Use of a wrought aluminum alloy in a T8 temper with the following composition, in wt%,

   Cu: 3.6 - 4.4

   Mg: 1.2 - 1.4

   Mn: 0.5 - 0.8

   Zr: 0.07 - 0.15

   Ti: 0.01- 0.05

   Si ≤ 0.20

   Fe ≤ 0.20

   Zn ≤ 0.25

   unavoidable impurities < 0.05

   the remainder being aluminum,

   in an application wherein said product is kept at temperatures of 100°C to 250°C for a significant period of at least 200 hours.
2. Use according to claim 1 wherein Cu is at least equal to 3.9 wt% and preferably at least equal to 4.0 wt% and/or Cu is at most 4.3 wt% and preferably at most 4.25 wt%.
3. Use according to claim 1 or claim 2 wherein the Mn content is between 0.51 and 0.65 wt%.
4. Use according to any one of claims 1 to 3 wherein Zr is at least equal to 0.08 wt%.
5. Use according to any one of claims 1 to 4 characterized in that the thickness of said wrought product is between 6 mm and 300 mm and preferably between 10 and 200 mm, given that if the wrought product is a profile, the thickness is defined as per the standard EN 2066:2001.
6. Use according to any one of claims 1 to 5 wherein said wrought product has in the longitudinal direction an ultimate tensile strength R_m of at least 490 MPa and preferably at least 495 MPa and has after long term exposure at 150°C for 1000h, an ultimate tensile strength R_m of at least 475 MPa and preferably at least 480 MPa, the ultimate tensile strength R_m, being determined by a tensile test as per the standard NF EN ISO 6892-1, the sampling and direction of the test being defined by the standard EN 485-1.
7. Use according to any one of claims 1 to 6 wherein said wrought product has a necessary period to attain a 0.35% deformation during a creep test as per the standard ASTM E139-06 for a stress of 250 MPa and at a temperature of 150°C of at least 700 hours and preferably of at least 800h.
8. Use according to any one of claims 1 to 7 wherein the process for manufacturing said wrought product comprises, successively,

   - preparing a liquid metal bath so as to obtain an aluminum alloy with a composition according to any one of claims 1 to 4,

   - casting said alloy typically in rolling ingot, extrusion billet or forging stock form,

   - optionally homogenizing the product thus cast so as to attain a temperature between 450°C and 520°C,

   - hot working the product thus obtained,

   - solution heat treating the product thus hot worked with a heat treatment enabling to reach a temperature between 485 and 520°C and preferably between 495 and 510°C for 15 min to 8 h, then quenching,

   - cold working the product thus solution heat treated and quenched,

   - ageing wherein the product thus obtained attains a temperature between 160 and 210°C and preferably between 175 and 195°C for 5 to 100 hours and preferably from 8 to 50h to obtain a T8 temper.
9. Use according to any one of claims 1 to 8, wherein the product is kept at temperatures of 100°C to 200°C.
10. Use according to any one of claims 1 to 9 wherein the application is a structural component or attachment means near engines in the automotive or aerospace industry.
11. Use according to any one of claims 1 to 9 wherein the application is a rotor or another component of an air suction pump such as a vacuum pump, preferably a turbomolecular pump.
12. Use according to any one of claims 1 to 9 wherein the application is a component of an air blowing device such as a booster.

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