Solution-hardening heat treatment method for profiled elements made of aluminium alloy

Abstract

The invention relates to a solution-hardening heat treatment method for a profiled element made of aluminium alloy, identified in an orthogonal coordinate system (X, Y, Z), where Y is the extrusion direction, with the cross section of the profiled element comprising a core which, in accordance with the EN2066-2022 standard, consists of at least a first elementary rectangle of dimensions A1, B1 with an aspect ratio A1 / B1 ranging from 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 ranging from 100 mm to 500 mm, and B1 is parallel to Z and ranges from 10 to 50 mm. The method comprises a step of solution heat treatment and a step of immersion hardening in a liquid-filled quenching tank such that, during the immersion step, the plane (Y, Z) of the profiled element is substantially parallel to the normal N to the surface of the liquid.

Description

[0001] DESCRIPTION

[0002] Title: Solution-quenching heat treatment method for aluminum alloy profiles

[0003] technical field

[0004] The invention relates to a solution-quenching heat treatment method for improving the machinability of profiles. The invention also relates to a process for manufacturing a profile using the solution-quenching heat treatment method, and the resulting product exhibits greater homogeneity of properties within the cross-section, as well as improved machinability.

[0005] Previous art

[0006] Extruded products, also called profiles, made of aluminum alloy are developed to produce high-strength parts intended in particular for the aeronautical and aerospace industries.

[0007] Extruded aluminum alloy products are used in the aerospace industry for many applications, such as fuselage stiffeners or stringers, fuselage frames, wing stiffeners, floor crossbeams and beams, and seat rails.

[0008] Generally, a profile is defined by the geometry of its cross-section. The cross-section of the profile corresponds to the section of the profile taken perpendicular to the direction of extrusion.

[0009] According to standard NF-EN 2066-2022 paragraph 3, the cross-section of a profile can be divided into elementary rectangles of dimensions A and B; A being always the largest dimension of the elementary part and B being considered as the thickness of this elementary rectangle of the profile (see Figure 1, taken from standard EN2066). A shape ratio can be defined using the ratio A / B.

[0010] Generally, the central parts of a profile, which in most cases have a high aspect ratio, are called the "web," while the parts that intercept or are adjacent to the web, which in most cases have lower aspect ratios, are called "flanges," and one of their directions is substantially perpendicular to the longest dimension of the web. In general, a web designates the central part of a profile, and a flange corresponds to a lateral part of the profile, intercepting or adjacent to the web, and one of whose directions is substantially perpendicular to the direction of the longest dimension of the web. A flange is a specific type of flange located at one end of the web. According to standard NF-EN 2066-2022, the web and flange(s) of a profile can be divided into elementary rectangles. The web is in contact with the flange(s) of the cross-section.An elementary rectangle of a flank either intercepts (in the case of a flank extending symmetrically on either side of the web) or is adjacent (in the case of an asymmetrical flank, for example, an L-shaped cross-section) to the elementary rectangle(s) of the web. In the case of Figure 1, the web corresponds to the elementary rectangle 20, and the cross-section has three flanks 30, 30', 30". In the case of a J-profile shown in Figure 2, the cross-section can be described by three elementary rectangles 20, 30, 35. The elementary rectangles 20 and 30 correspond respectively to the web and the flank of the J-profile. The elementary rectangle 35, which is located at the end of the flank 30, is not a flank in the sense of the invention because the elementary rectangle 35 does not intercept or is not adjacent to the elementary rectangle of the web.

[0011] EP3080319 (Constellium Issoire) discloses a raw spun product for the manufacture of a machined spun product for the aeronautical industry, in alloy composition in % by weight, Cu 2.0 - 6.0; Li 0.5 - 2.0; Mg 0 - 1.0; Ag 0 - 0.7; Zn 0 - 1.0; and at least one element chosen from Zr, Mn, Cr, Sc, Hf and Ti, the quantity of said element, if chosen, being 0.05 to 0.20 % by weight for Zr, 0.05 to 0.8 % by weight for Mn, 0.05 to 0.3 % by weight for Cr and for Sc, 0.05 to 0.5 % by weight for Hf and 0.01 to 0.15 % by weight for Ti, Si < 0.1; Fe < 0.1; other < 0.05 each and < 0.15 in total, having a rough web and a rough flank such that the dimension of the rough flank whose direction is perpendicular to the dimension of the length of the rough web is at least 20% greater than the length of the machined flank.

[0012] Extruded aluminum alloy products, particularly those used in the aerospace industry, are in most cases machined to achieve the final geometry of parts. It is crucial to be able to machine such profiles without deformation. Deformation of profiles during machining is related to internal stress levels. High levels of internal stress cause significant distortion during machining, making it impossible to machine these profiles.

[0013] It is known that quenching after solution heating of 2xxx or 7xxx series aluminum alloys can induce internal stresses. The presence of strong thermal gradients in the cross-section of the profile during quenching leads to inhomogeneous plastic deformation. When the product is completely cooled, it contains internal stresses, also known as residual stresses.

[0014] The most common methods for relieving residual stresses in 2xxx and 7xxx series alloy profiles involve plastic deformation by tensile stress reduction in the direction of the extrusion. CN108754363 (Central South University) describes a thermomechanical treatment including a 1 to 10% drawing step to reduce residual stresses. Hot or even boiling water quenching can also be used to reduce residual stresses, as presented in Techniques de l'ingénieur M 1 290v2, Heat Treatments of Aluminum Alloys.

[0015] - Materials and recommendations - Mr. Stucky page 19. However, this solution has the disadvantage of obtaining lower final properties than when the profile is soaked in water at room temperature.

[0016] There is a need to improve the machinability of aluminum alloy profiles, in particular profiles whose cross-section has a web and at least one flank for which the drawing solution is not sufficient.

[0017] Description of the invention

[0018] A first object of the invention relates to a solution-quenching heat treatment method for an aluminum alloy profile belonging to the 2XXX or 7XXX series. The profile is located in an orthogonal coordinate system (X, Y, Z). Y is the extrusion direction. The cross-section of said profile comprises a web and at least one flange.

[0019] The core is decomposed according to standard EN2066-2022 into at least one elementary rectangle of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50. A1 is the largest dimension and is parallel to X. A1 is from 100 mm to 500 mm. B1 is parallel to Z and is from 10 to 50 mm.

[0020] The side panel is decomposed according to standard EN2066-2022 into at least one second elementary rectangle with dimensions A2, B2, where A2 is the larger dimension. The dimension in mm of the second elementary rectangle perpendicular to the X direction is greater than or equal to 1.2 * B1 (in mm).

[0021] The solution-quenching heat treatment method comprises the following steps:

[0022] - (d1) the aluminium profile is placed in solution at a temperature of approximately 400 °C to 550 °C for a period of approximately 5 min to 15 h,

[0023] - (d2) the aluminium profile in solution is quenched in a quenching tank filled with liquid (10). During step (d2) the plane (F, Z) of the profile is substantially parallel to the normal N to the surface of the liquid.

[0024] Preferably, the first elementary rectangle of the web and the second rectangle of the side are intersecting or adjacent. Preferably, at least one first rectangle of the web satisfies that dimension A1 is between 100 mm and 500 mm, dimension B1 is between 10 and 50 mm, and that A1 / B1 is between 4 and 50. Preferably, the first elementary rectangle of the web is considered to be the one that intersects or is adjacent to the second elementary rectangle of the side and has the largest dimension B1.

[0025] Preferably, the spinning direction Y forms an angle alpha with the normal N to the surface of the liquid when the profile is immersed in the quenching tank filled with liquid such that the value of the angle alpha in degrees satisfies 70° < angle alpha < 90°, preferably 80° < angle alpha < 87°.

[0026] Preferably, the largest dimension A2 of the second elementary rectangle is perpendicular to the X direction.

[0027] Preferably, the A2 / B2 shape ratio of the second elementary rectangle is between 2 and 6.

[0028] Another object of the invention relates to a method for manufacturing an aluminum alloy profile comprising the following successive steps:

[0029] (a) a rough form is cast in 2XXX or 7XXX aluminum alloy,

[0030] (b) Optionally, the said raw form is homogenized,

[0031] (c) the said rough form is hot-formed by spinning so as to obtain an aluminium profile (1) located in an orthogonal coordinate system (X, Y, Z), where Y is the direction of spinning, and whose cross-section has a web and at least one flank. Said core is decomposed according to standard EN2066-2022 into at least one first elementary rectangle of dimensions A1, B1 with a aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 from 100 mm to 500 mm, and B1 is parallel to Z and from 10 to 50 mm, and said at least one side is decomposed according to standard EN2066-2022 into at least one second elementary rectangle of dimension A2, B2 where A2 is the largest dimension, and such that the dimension in mm of the second elementary rectangle perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 *B1,

[0032] (d) said aluminium profile (1) is put into solution and then quenched by immersion according to the first object of the invention relating to a heat treatment method of solution quenching,

[0033] (e) the said solution-quenched aluminium profile is fractionated in a controlled manner,

[0034] (f) optionally, the said fractionated spun product is dressed or shaped,

[0035] (g) income is realized from said fractional spun product.

[0036] Preferably, the 7XXX aluminum alloy is an alloy designated according to standard AA7075 or AA7175 or AA7010 or AA7050 or AA7349 or AA7449. Preferably, the 7XXX aluminum alloy is an alloy with the following weight percentages: Zn 5-9; Mg 2-3; Cu 1-3; at least one element selected from Cr, Mn, Zr, Ti, the content of the element, if selected, being Ti 0.01-0.15; Cr 0.01-0.3; Mn 0.01-0.3; Zr 0.01-0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum.

[0037] Preferably, the 7XXX aluminum alloy is an alloy with the following weight percentages: Zn 5-6.5; Mg 2-3; Cu 1.2-2; at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01-0.15; Cr 0.01-0.3; Mn 0.01-0.3; Zr 0.01-0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum.

[0038] Preferably, the 2XXX aluminum alloy is an Al-Cu-Li alloy designated according to standard AA2065 or AA2195 or AA2295 or AA2196 or AA2296 or AA2076 or AA2099 or AA2199.

[0039] Preferably, the aluminum alloy is an Al-Cu-Li alloy with the following composition by weight %: Cu 1-5; Li 0.5-2; Mg 0-4; Ag 0-0.7; Zn 0-1; and at least one element chosen from Zr, Mn, Cr, Sc, Hf and Ti, the quantity of said element, if chosen, being 0.04 to 0.20 wt% for Zr, 0.05 to 0.8 wt% for Mn, 0.05 to 0.3 wt% for Cr and Sc, 0.05 to 0.5 wt% for Hf and 0.01 to 0.15 wt% for Ti, Si < 0.1; Fe < 0.1; other elements < 0.05 each and < 0.15 in total, remainder aluminum.

[0040] Preferably, the aluminium alloy is an Al-Cu-Li alloy with the following composition by weight % Cu 2.3 - 3.3; Li 1.4 - 2.1; Mg 0.2 - 0.8; Ag 0.2 - 0.6; Zn < 0.35; Mn < 0.45; Zr 0.04 - 0.18; Ti < 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remaining aluminium.

[0041] Another object of the invention is an Al-Cu-Li aluminum alloy profile, obtainable by the manufacturing method, wherein the aluminum alloy is an Al-Cu-Li alloy with the following percentage compositions: Cu 2.3–3.3; Li 1.4–2.1; Mg 0.2–0.8; Ag 0.2–0.6; Zn < 0.35; Mn < 0.45; Zr 0.04–0.18; Ti < 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum. The profile is located in an orthogonal coordinate system (X, Y, Z), where Y is the extrusion direction, and whose cross-section has a web and at least one flange.The said core is decomposed according to standard EN2066-2022 into at least one first elementary rectangle of dimensions A1, B1 with a shape ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 of 100 mm to 500 mm, and B1 is parallel to Z and of 10 to 50 mm, and said at least one side is decomposed according to standard EN2066-2022 into at least one second elementary rectangle of dimension A2, B2 where A2 is the largest dimension, and such that the dimension of the second elementary rectangle perpendicular to the direction X of the first elementary rectangle is greater than or equal to 1.2 *B1.

[0042] The Al-Cu-Li aluminum alloy profile is characterized by the fact that the deviation (in %) of the yield strength measured in the L direction, corresponding to the spinning direction Ÿ, is less than 18% in absolute value regardless of the position in the cross-section of the profile.

[0043] Preferably, the Al-Cu-Li aluminum alloy profile is such that the maximum strain measured in the extrusion direction is less than 200 µm, preferably 150 µm, in any area of ​​the web, such that said web area is not in contact with a flange. The strain is measured using a strain gauge positioned at one end of the web in the extrusion direction Ÿ during successive machining operations that reduce the web dimension parallel to the X direction, starting from the side opposite the gauge, after all protruding flanges of the web have been machined.

[0044] Another object of the invention is a 7XXX aluminum alloy profile, obtainable by the manufacturing method, wherein the aluminum alloy is a 7XXX alloy with the following weight percentages: Zn 5-9; Mg 2-3; Cu 1-3; at least one element selected from Cr, Mn, Zr, Ti, the content of the element, if selected, being Ti 0.01-0.15; Cr 0.01-0.3; Mn 0.01-0.3; Zr 0.01-0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum. Preferably, the aluminum alloy has the following weight percentages: Zn 5-6.5; Mg 2-3; Cu 1.2-2; at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01 - 0.15; Cr 0.01 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, remaining aluminium.The profile is located in an orthogonal coordinate system (X, Y, Z), where Y is the spinning direction, and whose cross-section has a web and at least one flange. Said web is decomposed according to standard EN2066-2022 into at least one first elementary rectangle of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 ranging from 100 mm to 500 mm, and B1 is parallel to Z and ranging from 10 to 50 mm, and said at least one flange is decomposed according to standard EN2066-2022 into at least one second elementary rectangle of dimensions A2, B2 where A2 is the largest dimension, and such that the dimension of the second elementary rectangle perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 * B1.The 7XXX aluminum alloy profile is characterized by the fact that the deviation (in %) of the yield strength measured in the L direction, corresponding to the spinning direction Ÿ, is less than 18% in absolute value, preferably 10%, regardless of the position in the cross-section of the profile.

[0045] Preferably, the 7XXX aluminum alloy profile is such that the maximum strain measured in the extrusion direction is less than 200 µm / m in any area of ​​the web, such that said web area is not in contact with a flange. The strain is measured using a strain gauge positioned at one end of the web in the extrusion direction Ÿ during successive machining operations that reduce the web dimension parallel to the X direction, starting from the side opposite the gauge, after all protruding flanges of the web have been machined.

[0046] Figures

[0047] Figure 1 represents the principle of decomposition of a section of profiles into elementary rectangle(s) according to the EN2066-2022 standard.

[0048] Figure 2 represents a J-profile.

[0049] Figure 3 illustrates a quenched profile according to the principle of the invention. Figure 3a) shows a perspective view of a profile (1) with a web (2) and two sides (3) and (3'). Figure 3b) shows the cross-section broken down into elementary rectangles. Figure 3c) shows a perspective view of the profile above the surface of the liquid in the quenching tank according to one embodiment.

[0050] Figure 4 represents the projection of Figure 3 c) into the plane defined by the spinning direction Ÿ and the normal N to the surface of the liquid (100) in the quenching tank.

[0051] Figure 5 shows the cross-section of the profile in examples 1 and 2, as well as its decomposition into elementary rectangles.

[0052] Figure 6 represents the positioning of a profile on a stretcher (40) corresponding to the positioning during the quenching step of the reference case (case C of example 1).

[0053] Figure 7 represents the positioning of a profile on a stretcher corresponding to an embodiment according to the invention (case D of example 1 or case E of example 3).

[0054] Figure 8 represents a principle of implementation of the quenching solution process according to the invention.

[0055] Figure 9 shows an embodiment allowing the profile to be immersed on a stretcher at an angle alpha using a sling system. Figure 10 shows a cross-sectional view of a profile immersed in the quenching tank according to the positioning shown in Figure 6 (reference).

[0056] Figure 11 represents the cross-sectional view of a profile immersed in the quenching tank according to the positioning of Figure 7 (invention).

[0057] Figure 12, Figure 13, Figure 14, Figure 15 and Figure 16 represent the steps of the deformation measurement method used to assess the machinability of the profile.

[0058] Figure 17 represents the evolution of the measured deformation as a function of positioning in the machined web, using the method described in Figures 12 to 16 for the Al-Cu-Li profile described in Figure 5, after quenching according to the reference method or according to the method of the invention according to the conditions of Example 1.

[0059] Figure 18 represents the cross-section of the 7XXX profile from examples 3 and 4, as well as its decomposition into elementary rectangles.

[0060] Figure 19 represents the evolution of the measured deformation as a function of positioning in the machined web, using the method described in Figures 12 to 16 for the 7XXX profile described in Figure 18 and transformed according to the conditions of example 3.

[0061] Detailed description of the invention

[0062] Unless otherwise stated, all indications concerning the chemical composition of alloys are expressed as a percentage by weight based on the total weight of the alloy. The expression 1.4 Cu means that the copper content expressed as a percentage by weight is multiplied by 1.4. The designation of alloys complies with the regulations of The Aluminium Association, which are familiar to those skilled in the art. The definitions of the metallurgical states are given in the European standard EN 515.

[0063] The static mechanical characteristics in tension, in other words the tensile strength Rm, the conventional yield strength at 0.2% elongation Rp0.2, and the elongation at break A%, are determined by a tensile test according to the standard NF EN ISO 6892-1, the sampling and direction of the test being defined by the standard EN 485-1.

[0064] According to the invention, a profile 1 is considered to comprise a web and at least one flange. Figure 3 illustrates the case of a profile with a web 2 and two flanges 3 and 3'. This illustration is provided to illustrate the invention and is not limiting; the profile may contain one or more than two flanges. The web can be decomposed (Figure 3b) according to standard EN2066-2022 into at least one elementary rectangle 20 of dimensions A1, B1, where A1 is the larger dimension.

[0065] Dimensions A1 and B1 are such that A1 ranges from 100 mm to 500 mm and B1 from 10 mm to 50 mm, with an aspect ratio A1 / B1 of 4 to 50. Preferably, dimension A1 is at least 150 mm or 200 mm and at most 400 mm or 350 mm. Preferably, B1 is at least 15 mm or 20 mm and at most 40 mm or 30 mm. If dimension B1 is less than 10 mm, the invention offers no advantage. Preferably, the A1 / B1 ratio is at least 6 or 8 and at most 40 or 30.

[0066] We define a coordinate system (X, Y, Z) such that dimension A1 is parallel to the X direction, direction Y is parallel to the spinning direction and dimension B1 is parallel to the Z direction.

[0067] Each side can be decomposed according to standard EN2066-2022 into a second elementary rectangle (30 and 30' Figure 3 b)) of dimensions A2, B2 and A2', B2' where A2 and A2' are the larger dimensions. According to the invention, the first elementary rectangle (of the web) and the second elementary rectangle (of the side) are considered to be adjacent or intersecting.

[0068] According to the invention, the term "first elementary rectangle" is used for an elementary rectangle defining the core and "second elementary rectangle" for an elementary rectangle defining a flank.

[0069] According to the invention, the dimension of the at least second elementary rectangle, which is perpendicular to the X direction of the first elementary rectangle, is greater than or equal to 1.2 * B1, preferably 1.5 * B1 or 2 * B1, or even 2.2 * B1. In the case shown in Figure 3, the dimensions A2 and A2' are perpendicular to the X direction of the first elementary rectangle 20.

[0070] It is possible that the core can be described by several first elementary rectangles. In the case where the core can be described by more than one elementary rectangle (A1, B1), (A1', B1')... the value B1 to be considered corresponds to the maximum value (B1, B1', ...) of the first elementary rectangles (of the core) adjacent to or intersecting the considered side.

[0071] In cases where the web can be described by more than one primary rectangle, at least one primary rectangle is considered to satisfy the aforementioned dimensional conditions. Preferably, the dimension of at least one secondary rectangle perpendicular to the X direction of the primary rectangle of the web corresponds to dimension A2. Preferably, the aspect ratio (A2 / B2 or A27B2' or ...) of at least one secondary rectangle (side 20, 20', 20"...) is between 2 and 6.

[0072] The solution-quenching heat treatment method for an aluminum alloy profile according to the invention comprises solution quenching and immersion quenching. The inventors have observed that it is possible to improve the machinability of aluminum alloy profiles, particularly 2xxx or 7xxx series aluminum alloys, especially Al-Cu-Li alloys, by manipulating the web positioning of the profile during immersion quenching. The impact of quenching on the properties and machinability is amplified if the largest dimension of the web is significant, typically if A1 is greater than 150 mm.

[0073] The surface of the quenching liquid at rest is considered as a plane with normal N.

[0074] The inventors observed that it was detrimental to orient the web of the profile vertically relative to the liquid surface during quenching. "Orienting the web of the profile vertically" means that the X direction, parallel to the longer dimension of the web, is oriented approximately parallel to the normal to the quenching liquid surface. This practice, however, has the advantage of allowing a larger number of profiles to be processed simultaneously. Indeed, due to space constraints, a greater number of profiles can be immersed for a given liquid surface area when they are positioned with their webs vertical.

[0075] According to the invention, a direction is understood to be "substantially parallel" to another direction if these two directions are identical or form an angle of less than 10°, preferably less than 5°.

[0076] The inventors found that it was advantageous, on the contrary, for the web to be positioned substantially horizontally relative to the surface of the quenching liquid. "Orienting the web of the profile horizontally" means that the direction X, parallel to the longest dimension of the web, is oriented substantially perpendicular to the normal Jv of the liquid surface. According to the invention, a direction is understood to be substantially perpendicular to another if the angle between these two directions is 90° ± 10°, preferably ± 5°.

[0077] The inventors observed that it was possible to reduce the residual stresses measured in the profile if the (Y, Z) plane of the profile is substantially parallel to the normal N of the quenching liquid surface. This arrangement corresponds to "orienting the web of the profile horizontally." According to the invention, a plane is understood to be "substantially parallel" to a direction if the normal to that plane forms an angle of 80° to 90°, preferably 85° to 90°, with said direction.

[0078] The inventors have developed a measurement method to determine the level of residual stresses within a profile. Indeed, conventional measurement methods developed for rolled products cannot be used simply. Some methods only measure surface deformation, such as the so-called hole method, which involves drilling a small hole in the material and measuring the induced deformation, or the X-ray method. The so-called bar method, described in EP 0731185, for example, measures the residual stresses in the core of rolled products. It is based on measuring the deformation during incremental machining in the direction of the product's thickness. This method is not suitable for profiles whose residual stresses vary across the profile's cross-section.

[0079] The inventors developed a method for measuring deformation during incremental machining, using the same principle as the bar method. As with the bar method, the greater the deformation, the greater the residual stresses (also called internal stresses). The deformation is measured using a strain gauge positioned at one end of the web in the extrusion direction Ÿ. It is bonded to the (Z, Ÿ) face. The deformation is measured during successive machining operations that reduce the web dimension parallel to the X direction, starting from the side opposite the gauge, after the protruding flanks have been machined. This is equivalent to reducing the web dimension A1 by successive machining operations. The deformation is measured after each machining pass. The measurement method is described in more detail in Example 2.The measurement is preferably carried out until the dimension of the web parallel to the remaining X direction is close to 25 mm. Indeed, the inventors believe that if the dimension of the remaining web is less than 25 mm, the measured deformation may be overestimated due to a lack of web rigidity. The inventors believe that a measured deformation in the extrusion direction Ÿ of less than 200 µm / m, preferably 150 µm / m in any area of ​​the web not in contact with a flange and located more than 25 mm from the end of the web where the gauge is bonded, ensures good machining behavior, i.e., limited saber deformation of the profile during machining. Typically, the deflection measured over a machined length of 2 m, or even 6 m, is less than 3 mm.The inventors believe that this arrangement according to the invention allows the entire profile to be hardened almost simultaneously, which is beneficial with regard to the homogeneity of properties within the section of the profile and the reduction of internal stresses.

[0080] Advantageously, the profile is inclined at the moment of immersion and during immersion (Figure 4). This allows for better immersion and, above all, better evacuation of any heat-forming bubbles that may have formed on the surface of the profile during the initial stages of quenching. Advantageously, the drawing direction Ÿ of the profile forms an angle alpha with the direction N, corresponding to the normal direction of the surface of the quenching liquid, such that the angle alpha (in degrees) is strictly less than 90°, preferably at least 70°, 75°, or 80°, and preferably at most 89°, 88°, or 87°.

[0081] Aluminum alloy profiles are manufactured using a well-known process comprising a casting step, preferably a homogenization step, a heating step, a drawing step, an optional cutting-to-length step, a solution heating step, a quenching step, a tensile stress-relieving step, an optional straightening step, and a tempering step. The quenching step considered here by the invention is an immersion quenching step. It consists of plunging the profiles into a liquid as quickly as possible after the completion of the solution heating heat treatment. The profiles are usually held in place by slings or positioned on a stretcher, itself supported by slings, which can be immersed in a quenching tank.

[0082] In the manufacturing process of a profile according to the invention, a rough form is cast from a 2XXX or 7XXX aluminum alloy, preferably an Al-Cu-Li alloy. Preferably, the rough form is a billet. It is possible that the rough form is a plate from which a cylindrical shape can be extracted.

[0083] Preferably, the 2XXX aluminum alloy has a composition corresponding to an AlCuLi alloy. Advantageous 2XXX aluminum alloys for implementing the invention include AA2065, AA2195, AA2295, AA2196, AA2296, AA2076, AA2099, and AA2199. AA2196, AA2296, and AA2076 alloys are particularly preferred.

[0084] Preferably, the 2XXX aluminum alloy has a composition corresponding to an Al-Cu-Li alloy with the composition in % by weight of Cu 1 - 5; Li 0.5 - 2; Mg 0 - 4; Ag 0 - 0.7; Zn 0 - 1; and at least one element chosen from Zr, Mn, Cr, Sc, Hf and Ti, the quantity of said element, if chosen, being 0.04 to 0.20 % by weight for Zr, 0.05 to 0.8 % by weight for Mn, 0.05 to 0.3 % by weight for Cr and for Sc, 0.05 to 0.5 % by weight for Hf and 0.01 to 0.15 % by weight for Ti, Fe < 0.1; Si < 0.1; other elements < 0.05 each and < 0.15 in total, remainder aluminum.

[0085] Preferably, the 2XXX aluminum alloy is an Al-Cu-Li alloy with the following composition by weight %: Cu 2.3 - 3.3; Li 1.4 - 2.1; Mg 0.2 - 0.8; Ag 0.2 - 0.6; Zn < 0.35; Mn < 0.45; Zr 0.04 - 0.18; Ti < 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remaining aluminum.

[0086] Preferably, the 2XXX aluminum alloy is an Al-Cu-Li alloy with the following composition by weight %: Cu 2.8 - 3.2; Li 1.6 - 1.8; Mg 0.2 - 0.5; Ag 0.2 - 0.4; Zn < 0.15; Mn 0.2 - 0.4; Zr 0.04 - 0.18; Ti 0.02 - 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remaining aluminum.

[0087] Advantageous 7XXX aluminum alloys for carrying out the invention include AA7075 or AA7175 or AA7010 or AA7050 or AA7349 or AA7449 alloys.

[0088] Preferably, the 7XXX alloy has a weight composition % Zn 5 - 9; Mg 2 - 3; Cu 1 - 3, at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01 - 0.15; Cr 0.01 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, remainder aluminium.

[0089] Preferably, the 7XXX aluminum alloy is an alloy with the following weight percentages: Zn 5-6.5; Mg 2-3; Cu 1.2-2; at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01-0.15; Cr 0.01-0.3; Mn 0.01-0.3; Zr 0.01-0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum.

[0090] The resulting rough form is preferably homogenized. The homogenization temperature is preferably between 470 °C and 540 °C for 5 to 60 hours. Preferably, for an AlCuLi alloy, the homogenization temperature is between 500 °C and 530 °C. After homogenization, the rough form is generally cooled to room temperature before being preheated for hot forming. The preheating aims to reach an initial forming temperature preferably between 350 °C and 500 °C, preferably between 380 °C and 500 °C, preferably between 400 °C and 500 °C for an AlCuLi alloy, or preferably in the range of 450 °C to 480 °C, enabling the deformation of the rough form. The reheating step can also serve as a homogenization step if this is not done beforehand.

[0091] Hot forming is performed by extrusion to obtain a profile with a core and at least one flange. In the context of the invention, the cross-section of the extruded product can be described using elementary rectangles according to the recommendations of standard EN2066-2022 as defined earlier in the description.

[0092] The spinning conditions (speed and temperature) are determined empirically to ensure good productivity while guaranteeing surface quality and the absence of defects. The exact extrusion speeds and temperatures depend on the size of the starting billet, the size and shape of the spun section, the number of die openings, the capacity of the spinning press, and the spinning method (direct or indirect)—parameters well known to those skilled in the art.

[0093] The spun product thus obtained is then dissolved and quenched according to the solution-quenching heat treatment method of the invention. Advantageously, the dissolution is carried out at a temperature of approximately 400 to 550 °C, for 5 minutes to 15 hours, preferably from 440 to 540 °C. The duration may advantageously be from 15 minutes to 10 hours.

[0094] Quenching is carried out by immersion in a tank filled with liquid. The liquid can be water, an aqueous solution, or any other suitable liquid. The liquid temperature is preferably temperature-controlled from 15°C to 30°C, preferably from 20°C to 25°C.

[0095] The inventors found it advantageous for the (Y, Z) plane of the profile to be substantially parallel to the normal N of the liquid surface at the moment the profile is immersed in the liquid in the quenching tank (Figure 3). Preferably, the profile is kept immersed in the liquid in this position, preferably for a period of at least approximately 30 seconds. The total immersion time is typically from 30 seconds to 1 hour, preferably from 1 minute to 30 minutes.

[0096] This arrangement allows for faster complete immersion of the profile section and reduces the thermal gradients between the top and bottom of the web (i.e., the thermal gradient in the X direction). The inventors believe this is advantageous because it reduces the residual stress gradient along the web's height (A1). In the presence of at least one flange, the inventors believe this arrangement allows for the fastest possible immersion of at least part of the flange, thus cooling the web-flange junction as quickly as possible by thermal conductivity. This limits the thermal gradients. The inventors believe this also reduces the residual stresses in the Ÿ direction. This effect remains valid if the profile has two or more flanges.It is preferable to immerse all the flanges and the web almost simultaneously in order to limit the thermal gradients between the web and the flanges, as well as between each flange. In addition to reducing residual stress gradients after quenching, reducing thermal gradients ensures good homogeneity of mechanical properties within the cross-section, which is advantageous in itself and also improves stress-relieving efficiency and reduces residual stresses after stress-relieving. All of this helps to reduce residual stress levels in the Y direction, which are the cause of the deflection observed after machining in the Y-axis extrusion direction, also known as saber.

[0097] We speak of saber deformation, for example, when, if the flange of a profile is placed on a surface plate with the X direction of the profile's cross-section oriented perpendicular to the surface plate, the flange of the profile does not touch the plate at certain points in the Y direction of the extrusion. The saber is defined by the height of the deflection corresponding to the maximum distance between the surface of the plate and the flange of the profile. This deflection height is measured in the X direction.

[0098] Preferably, the profile is inclined at the time of immersion so that the Y direction, corresponding to the extrusion direction of the profile, forms an angle alpha with the N direction of the liquid surface, and such that the angle alpha (in degrees) is strictly less than 90° and preferably greater than or equal to 70°. Preferably, the angle alpha is such that 70° < angle alpha < 90°, or 70° < angle alpha < 87°, or 75° < angle alpha < 87°, or 80° < angle alpha < 87°, so that heat-retaining bubbles do not remain trapped at the side(s). The removal of bubbles promotes heat exchange and consequently improves the quenching rate, which is beneficial for the mechanical properties and the homogeneity of properties across the profile's cross-section.

[0099] The spun product, once dissolved and quenched, then undergoes controlled tensile stress relieving, preferably of 1 to 5% and preferably of at least 2% in plastic deformation value. Known processing steps such as straightening or shaping may optionally be carried out before or after controlled tensile stress relieving.

[0100] Income is preferably generated at a temperature of 100 to 190 °C for 5 to 100 h, preferably at 120 to 185 °C for 12 to 40 h.

[0101] The inventors found that a process such as the one described above reduces the inconsistencies in yield strength measured in the L direction across the cross-section of the profile and improves machinability. The inventors attribute these improvements to the fact that the quenching method allows for almost simultaneous cooling of the entire profile, which is beneficial for the homogeneity of its properties. This reduces residual stresses after quenching and results in homogeneous mechanical properties during stress relieving, which is advantageous for reducing residual stresses and improving the machinability of the profile in the tempered state.

[0102] This beneficial effect of the quenching method is observed on both 2XXX alloy products, particularly Al-Cu-Li, and 7XXX alloy products.

[0103] In particular, on an Al-Cu-Li aluminum alloy profile with the following composition by weight %: Cu 2.3 - 3.3; Li 1.4 - 2.1; Mg 0.2 - 0.8; Ag 0.2 - 0.6; Zn < 0.35; Mn < 0.45; Zr 0.04 - 0.18; Ti < 0.10; Fe < 0.15; Si < 0.12;other elements < 0.05 each and < 0.15 in total, remains aluminium, with a core 2 and at least one flange (3, 3'), said core 2 is decomposed according to standard EN2066-2022 into at least one first elementary rectangle 20 of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 from 100 mm to 500 mm, and B1 is parallel to Z and from 10 to 50 mm, and the at least one flange (3, 3') is decomposed according to standard EN2066-2022 into at least one second elementary rectangle 30 of dimension A2, B2 where A2 is the largest dimension, and such that the dimension in mm of the second elementary rectangle perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 * B1 exhibits a deviation (in %) of yield strength measured in the L direction less than 18% in absolute value regardless of the position in the cross section of the profile.;

[0104] Preferably, the 2XXX aluminum alloy is an Al-Cu-Li alloy with the following composition by weight %: Cu 2.8 - 3.2; Li 1.6 - 1.8; Mg 0.2 - 0.5; Ag 0.2 - 0.4; Zn < 0.15; Mn 0.2 - 0.4; Zr 0.04 - 0.18; Ti 0.02 - 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remaining aluminum.

[0105] The beneficial effect of the quenching according to the invention is also characterized on a 7XXX alloy profile with a weight composition % Zn 5 - 9, Mg 2 - 3, Cu 1 - 3, at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01 - 0.15; Cr 0.1 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, remains aluminium, with a core (2) and at least one flange (3, 3'), said core (2) is decomposed according to standard EN2066-2022 into at least a first elementary rectangle 20 of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 of 100 mm to 500 mm, and B1 is parallel to Z and of 10 to 50 mm, and the at least one flange (3, 3') is decomposed according to standard EN2066-2022 into at least a second elementary rectangle 30 of dimension A2, B2 where A2 is the largest dimension,and such that the dimension in mm of the second elementary rectangle perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 * B1. Said profile exhibits a deviation (in %) of yield strength measured in the L direction of less than 18% in absolute value regardless of the position in the cross-section of the profile, preferably less than 10%.

[0106] Preferably, the 7XXX aluminum alloy is an alloy with the following weight percentages: Zn 5-6.5; Mg 2-3; Cu 1.2-2; at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01-0.15; Cr 0.01-0.3; Mn 0.01-0.3; Zr 0.01-0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, the remainder being aluminum.

[0107] The inventors have observed that the maximum deformation measured during a machining operation is reduced when the profile is made of alloy 2XXX, preferably Al-Cu-Li, or alloy 7XXX, according to the invention. The inventors have shown that machinability can be correlated with a measurement of the deformation in the extrusion direction Ÿ. The inventors have found that it is possible to obtain a maximum deformation in absolute value of the measured strain in the extrusion direction Ÿ of less than 200 µm, preferably 150 µm, in any area of ​​the web not in contact with a flange. The inventors believe that such deformation levels reduce the deformation of the profile during machining. Indeed, the inventors believe that obtaining a deformation value of less than 200 µm, preferably 150 µm, according to the measurement principle described below, characterizes a profile with a low level of internal stresses.

[0108] The strain is measured using a strain gauge positioned at one end of the web in the spinning direction. It is bonded to the (Z, Ÿ) face. The strain is measured during successive machining operations that reduce the web dimension parallel to the X direction, starting from the side opposite the gauge, after the protruding flanges have been machined. This is equivalent to reducing the web dimension A1 by successive machining. The strain is measured after one machining pass. The measurement is preferably performed until the web dimension parallel to the X direction is less than 25 mm. According to the invention, the strain measured in the spinning direction Ÿ is preferably considered to be less than 200 µm, preferably 150 µm, in any area of ​​the web not in contact with a flange and located more than 25 mm from the end of the web where the gauge is bonded. The measurement method is described in more detail in example 2.The spun product can notably be machined to obtain a wing stiffener, a fuselage stiffener, a fuselage frame, a floor beam or a floor cross member.

[0109] Examples

[0110] Example 1

[0111] Two billets with a diameter of 380 mm were cast, with a similar composition (Table 1) corresponding to an Al-Cu-Li alloy according to the invention. The billets underwent a homogenization treatment of approximately 8 hours at 524 °C. These billets were then reheated to a temperature of approximately 420 °C and subsequently drawn using a reverse drawing process at a speed of approximately 1.2 m / min. After drawing, the profile was cut to a length of approximately 15 m.

[0112] The profile has a cross-section with a web and three flanks extending symmetrically with respect to the web (see Figure 5). The cross-section of the profile is such that it is possible to decompose its section into five elementary rectangles according to the recommendations of standard EN 2066-2022 (Figure 5). The web is described by two first elementary rectangles 20 and 20', a first elementary rectangle 20 with dimension A1 of 242 mm and dimension B1 of 19 mm (aspect ratio 12.7), another first elementary rectangle 20' with dimension AT of 195 mm and dimension BT of 21 mm. The flanks are described by three second elementary rectangles 30, 30' and 30”. A second elementary rectangle 30 corresponding to the flange of the profile has dimension A2 of 57 mm and dimension B2 of 13 mm (aspect ratio 4.4), another second elementary rectangle 30' corresponding to a side of dimension A2' of 53 mm and dimension B2' of 20 mm (aspect ratio 2.65) and another second elementary rectangle 30” corresponding to another side of dimension A2” of 55 mm and dimension B2” of 20 mm (aspect ratio 2.75) (see Figure 5).

[0113] We denote Ÿ the spinning direction. The direction parallel to the length A1 and AT of the elementary rectangles of the web 20 and 20' is denoted X and the direction parallel to the dimension B1 and B1' of the elementary rectangles of the web 20 and 20' is denoted Z.

[0114] For each of the flanks, the dimensions A2, A2', and A2" of the corresponding elementary rectangle are perpendicular to the X direction and such that the length of the corresponding elementary rectangles is greater than 1.2 * BT. More precisely, for elementary rectangle 30, we have a ratio A2 / B1' = 57 / 21 = 2.7; for elementary rectangle 30', a ratio A2 / BT = 53 / 21 = 2.5; for elementary rectangle 30", a ratio A2 / B1' = 55 / 21 = 2.6. The ratio A2 / B1' is calculated because BT is the maximum dimension of the first two elementary rectangles of the core that intercept the flanks 30, 30', and 30" under consideration.

[0115] The profiles are dissolved at a temperature of 524 °C for 45 minutes and quenched in a quenching tank filled with water maintained at an ambient temperature of approximately 20-30 °C, according to the principle shown in Figure 8. The profiles are positioned on a stretcher 40. In one case corresponding to the reference case, used for profiles from billet C, the profiles are positioned such that the (Y, Z) plane is perpendicular to the normal N of the liquid surface at the time of quenching, according to the principle shown in Figures 6 and 10. In another case corresponding to the invention, used for profiles from billet D, the profiles are positioned such that the (Y, Z) plane is parallel to the normal N of the liquid surface at the time of quenching, according to the principle shown in Figures 7 and 11. It is possible to use wedges to hold the profile in position.In each case, the Y direction makes an angle alpha of approximately 84° with respect to the normal N of the liquid surface at the time of immersion and during immersion, such that the heat-absorbing bubbles can escape along the Y-direction of the core's spinning. This is particularly relevant for the positioning according to the invention (case D).

[0116] In both cases, the profiles are arranged on a stretcher 40 that can be placed in the solution furnace 50 and in the quenching tank 10 (Figure 8). A rail system 60 can facilitate the removal 51 of the profiles from the furnace. The profiles are arranged on the stretcher so that, at the time of immersion in the quenching tank, the plane (F, Z) is perpendicular (reference) or parallel (invention) to the normal N of the liquid surface at the time of quenching. The 84° inclination of the profile according to the invention is obtained using a lifting means 70 and lifting components, also called slings: the stretcher is held by means of slings 70, and the lifting means is configured to orient the stretcher at an angle of approximately 84° (Figure 9). The inclination is maintained throughout the immersion time.

[0117] After quenching, the profiles were then tensile-tested to approximately 3% and then returned to the T8 state by means of a 30 h heat treatment at 152 °C.

[0118] The tensile mechanical properties were measured at different positions in the cross-section (see Figure 5) for both cases. The tensile specimens were loaded in the direction of the extrusion. Positions 1, 2, and 3 are located in the web corresponding to the elementary rectangles 20 and 20', and positions 3 and 4 are located in the flank corresponding to the elementary rectangle 30'. [Table 1] - Chemical composition by weight %

[0119] [Table 2] - Mechanical properties in tension at different positions of the section.

[0120] The inventors observed improved homogeneity of tensile properties within the cross-section of the hardened profile according to the invention. Proportionally, the difference in yield strength measured between two positions is minimized (in absolute value) when the hardening treatment is carried out according to the invention (see Table 3).

[0121] [Table 3] - Variation in yield strength in % between different positions in the section of the profile.

[0122] According to the invention, a deviation (in %) of the elastic limit measured in the L direction of less than 18% in absolute value is measured regardless of the position in the section of the profile.

[0123] Example 2 A measurement method was developed to account for the propensity of the profile to deform during machining on profiles of the same type as Example 1. A length of 1 m of profile was considered for each of the tested cases. A unidirectional 200 strain gauge with a nominal resistance of 120 Ohms is bonded in the extrusion direction Ÿ of the profile at mid-length of the cut length on the underside of the base, midway from the edges in the ~Z direction (Figure 12).

[0124] Initially, the sides corresponding to the elementary rectangles 30, 30' and 30" are machined in several stages alternately from one side and the other so that the profile deforms very little in a saber shape.

[0125] The machining passes (No. 1, No. 2, ...) are indicated by the numbered dashed lines in Figure 12. The number of passes is preferably adjusted to have a minimum depth of cut of 1 mm and a maximum depth of cut of 4 mm in order to limit the deformation of the profile. Once the portions of the flanges extending beyond the web have been machined, only the portion of the web corresponding to the two elementary rectangles 20 and 20' already described in Example 1 remains (Figure 13). An initial measurement of the deformation is then taken after positioning the profile on supports placed near the ends of the profile, and the gauge is reset to zero (Figure 14). The web is then machined to reduce dimension A1, then A1', starting from the side opposite the gauge (Figure 15). The machining passes are a minimum of 1 mm and a maximum of 4 mm. The pass before measurement is a minimum of 1 mm and a maximum of 2 mm.Periodically, at the end of machining after the metal has cooled, the deformation is measured (Figure 16). Figure 16 illustrates the saber deformation. The measurement is stopped when the remaining dimension A1 is less than 25 mm. The machining parameters are chosen to avoid heating during machining and thus limit the creation of local residual stresses during machining.

[0126] Figure 17 shows the evolution of the deformation in the extrusion direction measured by the gauge in the case of quenching according to the invention or according to the reference, as a function of the pass position, i.e., as a function of the new dimension A1 of the remaining profile piece after machining in the X direction. The reduction of dimension A1 begins on the side opposite the gauge. A lower level of deformation in absolute value is observed for the profile quenched according to the invention. The difference is particularly visible in the part corresponding to the initially flankless area of ​​the profile: at the center of this part (ordinate = 68 mm), approximately -120 µm / m are measured by the gauge instead of approximately -200 / -240 µm / m for quenching according to the reference. The inventors consider that this type of measurement accounts for the lower propensity of the profile to deform after machining when it is quenched according to the invention.Indeed, the most problematic deformations during machining of this type of profile are saber deformations (a deflection in the X direction resulting from a deformation of the flange in the Ÿ direction that differs from the deformations of the rest of the profile in the Ÿ direction, thus creating bending). Therefore, the proposed test allows us to classify the different cases according to the order in which they occur during the machining of a profile with a web and one or more flanges in the extrusion direction.

[0127] Example 3

[0128] Two billets with a diameter of 372 mm were cast, with a similar composition (Table 4) corresponding to a 7xxx alloy according to the invention. The billets underwent a homogenization treatment of approximately 4 hours at 475 °C + 21 hours at 483 °C. These billets were then reheated to a temperature of approximately 385 °C and subsequently drawn using a reverse drawing process at a speed of approximately 0.5 m / min. After drawing, the profile was cut to a length of approximately 6 m.

[0129] The profile has a cross-section with a web and three flanges extending symmetrically around the web (see Figure 18). The cross-section of the profile can be decomposed into five elementary rectangles according to the recommendations of standard EN 2066-2022 (Figure 18). The web is described by two elementary rectangles, 20 and 20', a first elementary rectangle 20 with dimension A1 of 246 mm and dimension B1 of 22 mm (aspect ratio 11.2), and another first elementary rectangle 20' with dimension AT of 198 mm and dimension BT of 22 mm. The flanges are described by three second elementary rectangles, 30, 30', and 30”.A second elementary rectangle 30 corresponds to the flange of the profile with dimensions A2 of 59 mm and B2 of 17 mm (aspect ratio 3.5), another second elementary rectangle 30' corresponds to a flange with dimensions A2' of 56 mm and B2' of 18 mm (aspect ratio 3.1), and another second elementary rectangle 30” corresponds to another flange with dimensions A2” of 56 mm and B2” of 21 mm (aspect ratio 2.8) (see Figure 18). The spinning direction is denoted by Ÿ. The direction parallel to lengths A1 and AT of the elementary rectangles of the web 20 and 20' is denoted X, and the direction parallel to dimensions B1 and B1' of the elementary rectangles of the web 20 and 20' is denoted Z. For each of the flanges, dimensions A2, A2', and A2” of the corresponding elementary rectangle are perpendicular to the direction X and such that the length of the corresponding elementary rectangles is greater than 1.2 * BT.More precisely, for the elementary rectangle 30, we have a ratio A2 / B1' = 59 / 22 = 2.7; for the elementary rectangle 30', a ratio A27BT = 56 / 22 = 2.5; for the elementary rectangle 30”, a ratio A2” / B1' = 56 / 22 = 2.5. We calculate the ratio A2 / B1' because BT is the maximum dimension of the first two elementary rectangles of the web that intercept the flanks 30, 30' and 30” considered.

[0130] The profiles are placed in solution at a temperature of 472 °C for 60 minutes and quenched in a quenching tank filled with water maintained at an ambient temperature of approximately 20-25 °C according to the principle of Figure 8. The profiles are positioned on a stretcher 40. The profiles are positioned such that the plane (Y, Z) is parallel to the normal N of the liquid surface at the time of quenching, according to the principle of Figures 7 and 11. The direction Ÿ makes an angle alpha of approximately 84° with respect to the normal N of the liquid surface at the time of immersion and during immersion so that the heat-forming bubbles can escape along the spinning direction Ÿ of the web.

[0131] After quenching, the profiles were then tensile tested at approximately 2% and then tempered to the T79 condition using a two-step tempering process of 12h 120 °C + 6h 165 °C.

[0132] The tensile mechanical properties were measured at different positions in the cross-section (see Figure 18) at the beginning and end of the spinning process. The tensile test specimens were loaded in the spinning direction. Positions 1, 2, and 3 are located in the web corresponding to the elementary rectangles 20 and 20', and positions 3 and 4 are located in the flank corresponding to the elementary rectangle 30'.

[0133] [Table 4] - Chemical composition by weight %

[0134] [Table 5] - Mechanical properties in tension at different positions of the section. [Table 6] - Variation in yield strength in % between different positions in the section of the profile.

[0135] According to the invention, a deviation (in %) of the elastic limit measured in the L direction of less than 10% in absolute value is measured regardless of the position in the section of the profile and the position in the length of the profile.

[0136] Example 4

[0137] A 7XXX profile, processed according to the invention under conditions similar to those of Example 3, was characterized to account for its propensity to deform during machining. The same method as that described in Example 2 was used for this purpose.

[0138] Figure 19 shows the evolution of the deformation in the direction of spinning Ÿ measured by the gauge according to the same measurement principle as that described in example 2. It can be seen that the level of deformation of the profile 7XXX hardened according to the principle of the invention is less than 195 pm / m in absolute value regardless of the position in the web.

[0139] List of drawing references:

[0140] 1: Profile 50: Solution furnace

[0141] 2: soul 51: oven door

[0142] 3: side 60: rail

[0143] 10: Quenching tank 70: Slings

[0144] 20: Elementary rectangle core 100: surface of the quenching liquid

[0145] 30: basic rectangle, side 200: gauge

Claims

DEMANDS 1. Solution-quenching heat treatment method for an aluminum alloy profile (1) 2XXX or 7XXX, located in an orthogonal coordinate system X, Y, Z). Y is the spinning direction, and the cross-section of said profile comprises a web (2) and at least one flange (3), said web is decomposed according to standard EN2066-2022 into at least one first elementary rectangle (20) of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 from 100 mm to 500 mm and B1 is parallel to Z and from 10 to 50 mm, said at least one flange (3) is decomposed according to standard EN2066-2022 into at least one second elementary rectangle (30) of dimensions A2, B2, where A2 is the largest dimension, and such that the dimension of the second elementary rectangle perpendicular to the direction X is greater than or equal to 1.2 * B1 (in mm), said method comprises the following steps: (d1) The aluminium profile (1) is placed in solution at a temperature of approximately 400 °C to 550 °C for a period of approximately 5 min to 15 h, (d2) the aluminium profile (1) put in solution is quenched in a quenching tank filled with liquid (10), characterized in that during step (d2) the plane (F, Z) of the profile is substantially parallel to the normal N to the surface of the liquid (100).

2. Solution-quenching heat treatment method according to claim 1 wherein the spinning direction Y forms an angle alpha with the normal N to the surface of the liquid when the profile is immersed in the quenching tank filled with liquid such that the value of the angle alpha in degrees satisfies 70° < angle alpha < 90°, preferably 80° < angle alpha < 87°.

3. Solution-quenching heat treatment method according to claim 1 or 2 where the largest dimension A2 of the second elementary rectangle (30) is perpendicular to the X direction.

4. Solution-quenching heat treatment method according to any one of claims 1 to 3 where the shape ratio A2 / B2 of the second elementary rectangle (30) is from 2 to 6.

5. Method for manufacturing an aluminum alloy profile comprising the following successive steps: (a) a rough form is cast in 2XXX or 7XXX aluminum alloy, (b) Optionally, the said raw form is homogenized, (c) The said rough form is hot-formed by extrusion to obtain an aluminium profile (1) located in an orthogonal coordinate system X, Y, Z, where Y is the extrusion direction, the cross-section of which has a web (2) and at least one flange (3). The web (2) is decomposed according to standard EN2066-2022 into at least one first elementary rectangle (20) of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 ranging from 100 mm to 500 mm, and B1 is parallel to Z and ranging from 10 to 50 mm. The at least one flange (3) is decomposed according to standard EN2066-2022 into at least one second elementary rectangle (30) of dimensions A2, B2, where A2 is the largest dimension, and such that the dimension in mm of the second elementary rectangle is perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 * B1, (d) the said aluminium profile (1) is dissolved and then quenched by immersion, (e) the said solution-tempered aluminium profile is subjected to controlled tension, (f) optionally, the said spun-drawn product is dressed or shaped, (g) income is realized from said spun-pulled product, characterized in that step (d) is carried out according to any one of claims 1 to 4.

6. Method of manufacturing an aluminum alloy profile according to claim 5 wherein the aluminum alloy 7XXX is an alloy designated according to standard AA7075 or AA7175 or AA7010 or AA7050 or AA7349 or AA7449.

7. Method of manufacturing an aluminum alloy profile according to claim 5 where the aluminum alloy 7XXX is an alloy of composition by weight % Zn 5 - 9; Mg 2 - 3; Cu 1 - 3; at least one element chosen from Cr, Mn, Zr, Ti, the content of the element, if chosen, being Ti 0.01 - 0.15; Cr 0.01 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, remainder aluminium.

8. Method of manufacturing an aluminum alloy profile according to claim 7 wherein the aluminum alloy 7XXX is an alloy of composition by weight % Zn 5 - 6.5; Mg 2 - 3; Cu 1.2 - 2; at least one element selected from Cr, Mn, Zr, Ti, the content of the element, if selected, being Ti 0.01 - 0.15; Cr 0.01 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2; other elements < 0.05 each and < 0.15 in total, remainder aluminum.

9. Method of manufacturing an aluminium alloy profile according to claim 5 wherein the aluminium alloy 2XXX is an Al-Cu-Li alloy designated according to standard AA2065 or AA2195 or AA2295 or AA2196 or AA2296 or AA2076 or AA2099 or AA2199.

10. Method of manufacturing an aluminum alloy profile according to claim 5, wherein the composition of the aluminum alloy profile is an Al-Cu-Li alloy with the following weight percentages: Cu 1-5; Li 0.5-2; Mg 0-4; Ag 0-0.7; Zn 0-1; and at least one element selected from Zr, Mn, Cr, Sc, Hf and Ti, the quantity of said element, if selected, being 0.04 to 0.20 wt% for Zr, 0.05 to 0.8 wt% for Mn, 0.05 to 0.3 wt% for Cr and Sc, 0.05 to 0.5 wt% for Hf and 0.01 to 0.15 wt% for Ti, Si < 0.1; Fe < 0.1; other elements < 0.05 each and < 0.15 in total, remainder aluminium.

11. Method of manufacturing an aluminum alloy profile according to claim 10, wherein the composition of the aluminum alloy profile is an Al-Cu-Li alloy with the following weight percentages: Cu 2.3–3.3; Li 1.4–2.1; Mg 0.2–0.8; Ag 0.2–0.6; Zn < 0.35; Mn < 0.45; Zr 0.04–0.18; Ti < 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remains aluminium.

12. Aluminum alloy profile Al-Cu-Li, obtainable by the method according to claim 11, having a composition in % of Cu 2.3–3.3; Li 1.4–2.1; Mg 0.2–0.8; Ag 0.2–0.6; Zn < 0.35; Mn < 0.45; Zr 0.04–0.18; Ti < 0.10; Fe < 0.15; Si < 0.12; other elements < 0.05 each and < 0.15 in total, remaining aluminum, located in an orthogonal coordinate system (X, Y, Z), where Y is the extrusion direction of the profile, whose cross-section has a web (2) and at least one flank (3). Said web (2) is decomposed according to standard EN2066-2022 into at least one first elementary rectangle (20) of dimensions A1, B1 with an aspect ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 ranging from 100 mm to 500 mm, and B1 is parallel to Z and ranging from 10 to 50 mm. Said at least one flank (3) is decomposed according to standard EN2066-2022 into at least one second elementary rectangle (30) of dimensions A2, B2 where A2 is the largest dimension, and such that the dimension in mm of the second elementary rectangle perpendicular to the X direction of the first elementary rectangle is greater than or equal to 1.2 * B1, characterized in that the deviation (in %) of the yield strength measured in the L direction, corresponding to the spinning direction Ÿ, is less than 18% in absolute value regardless of the position in the cross-section of the profile.

13. Al-Cu-Li aluminum alloy profile according to claim 12 wherein the maximum strain measured in the spinning direction is less than 200 pm / m, preferably 150 pm / m, in any area of ​​the web, such that said area of ​​the web is not in contact with a flank and wherein the strain is measured using a strain gauge (200) positioned at one end of the web in the spinning direction Ÿ during successive machining reducing the dimension of the web parallel to the direction X ( A1 , A'1 ) from the side opposite the gauge after all the flanks protruding from the web have been machined.

14. Aluminum alloy profile 7XXX, obtainable by the method according to claim 7, of composition by weight % Zn 5 - 9; Mg 2 - 3; Cu 1 - 3; at least one element selected from Cr, Mn, Zr, Ti, the content of the element, if selected, being Ti 0.01 - 0.15; Cr 0.01 - 0.3; Mn 0.01 - 0.3; Zr 0.01 - 0.18; Fe < 0.5; Si < 0.2;other elements < 0.05 each and < 0.15 in total, remainder aluminium, located in an orthogonal coordinate system (X, Y, Z), where Y is the direction of extrusion of the profile, the cross-section of which has a web (2) and at least one flank (3) said web (2) is decomposed according to standard EN2066-2022 into at least a first elementary rectangle (20) of dimensions A1, B1 with a form ratio A1 / B1 of 4 to 50, where A1 is the largest dimension and is parallel to X, with A1 of 100 mm to 500 mm, and B1 is parallel to Z and of 10 to 50 mm, and said at least one flank (3) is decomposed according to standard EN2066-2022 into at least a second elementary rectangle (30) of dimension A2, B2 where A2 is the dimension; the largest, and such that the dimension in mm of the second elementary rectangle perpendicular to the direction X of the first elementary rectangle is greater than or equal to 1.2 *B1, characterized in that the deviation (in %) of the yield strength measured in the direction L, corresponding to the spinning direction Ÿ is less than 18% in absolute value, preferably less than 10% regardless of the position in the cross-section of the profile.

15. Aluminum alloy profile 7xxx according to claim 14 wherein the maximum strain measured in the spinning direction is less than 200 mm in any area of ​​the web, wherein said area of ​​the web is not in contact with a flank and wherein the strain is measured using a strain gauge (200) positioned at one end of the web in the spinning direction Ÿ during successive machining reducing the dimension of the web parallel to the direction X ( A1 , A'1 ) from the side opposite the gauge after all the flanks protruding from the web have been machined.

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