RU2757280C1 - Method for manufacturing plate product made of aluminum alloy of 7xxx series, which has improved fatigue resistance - Google Patents

Abstract

FIELD: manufacturing a plate product.

SUBSTANCE: invention relates to a method for manufacturing a plate product made of an aluminum alloy of the 7xxx series and can be used in aerospace engineering, in particular for panels and wing skin elements. The method for manufacturing a plate product from an aluminum alloy of the 7xxx series includes casting an ingot, homogenization and/or preheating of the cast ingot, hot rolling to obtain a plate product with a thickness of less than 75 mm in several passes, while when the intermediate thickness of the plate is from 80 to 220 mm, at least one pass of hot rolling with a high degree of compression is carried out with a decrease in thickness of at least 25%, while the deformation rate during at least one pass of hot rolling with a high degree of compression is < 1 s^-1. Additionally, the method includes heat treatment on a solid solution of a plate product, cooling, preferably by quenching, optionally stretching the plate product subjected to heat treatment on the solid solution and cooling, and artificial aging of the plate product subjected to heat treatment on the solid solution and cooling.

EFFECT: invention is aimed at increasing the resistance to fatigue failure.

15 cl, 2 dwg, 2 tbl

Description

The present invention relates to a method for manufacturing a 7xxx series aluminum alloy plate product having improved fatigue resistance. The plate product is ideal for aerospace engineering applications such as panels and wing skins, as well as other high strength end products.

State of the art

Al-Zn-Mg- (Cu) or AA7xxx series alloys have been used in aircraft structures for over 50 years, and especially in wing elements, for example, AA7055 series alloys have been used, among other things. These aluminum alloys offer the right balance of strength, fracture toughness and corrosion resistance, and are particularly well suited for aerospace engineering such as upper wing skins. This is disclosed, for example, in US Pat. No. 5,221,377. This US patent discloses that in order to obtain such high mechanical properties, alloys must be subjected to a three-stage artificial aging process. However, this US patent does not address the fatigue resistance property of AA7055 alloys.

It is known that high-strength structural components that are durable and resistant to damage, as well as resistance to fatigue failure, are highly desirable for aircraft manufacturers. Durability and resistance to damage can result in longer aircraft inspection intervals. An airplane typically requires two types of inspections: an initial inspection and a periodic inspection over the life of the airplane. Each type of inspection is very costly as the aircraft must be taken out of service in order for the inspection to take place. Inspections may require detailed visual inspection and extensive non-destructive testing of external and internal structures.

US Pat. No. 7,097,719 discloses that the fatigue strength of AA7055 series alloys can be improved by using an optimized alloy composition, later registered as AA7255 alloy. However, to achieve improved fatigue resistance, AA7255 alloys need to have much tighter upper limits for Si and Fe levels than AA7055. In particular, this US patent discloses that articles made from AA7255 alloy having lower Si and Fe levels than AA7055 (i.e., Si and Fe concentrations below 0.06 wt%, preferably below 0.04 wt% .%), demonstrate better resistance to fatigue fracture. In particular, in the US patent in the example section, it is disclosed that alloys containing less than 0.029 wt. % Si and less than 0.039 wt. % Fe (while maintaining the content of Cu, Mg, Zn and Zr within the ranges of the standard alloy AA7055), achieved an increase in fatigue life compared to products from the standard alloy AA7055 with a higher content of Si and Fe. Accordingly, the fatigue life of the AA7255 aluminum alloy product compared to the AA7055 standard alloy product can be improved. This improvement extends the inspection intervals of the aircraft structure. However, keeping the content of Si and Fe impurities at such a very low level increases the cost of the aluminum alloy produced, since it is necessary to use materials with a very high degree of purity.

Since fatigue characteristics, in particular resistance to fatigue fracture, are an important technical parameter for aerospace aluminum alloy materials due to the cyclic loads experienced by an aircraft during operation, there is a need to further improve or further increase the resistance to fatigue fracture of AA7xx series alloys, including alloys of the series AA7055.

Thus, there is a need for alloys of the Al-Zn-Mg- (Cu) type having desirable properties of strength, toughness and corrosion resistance, as well as high fatigue resistance. There is also a need for aircraft structural parts that exhibit high fatigue resistance.

Disclosure of the essence of the invention

The object of the present invention is to provide a method for manufacturing a 7xxx series aluminum alloy plate product having high fatigue resistance compared to 7xxx series alloys and, in particular, with AA7055 aluminum alloy plate products of similar dimensions and degrees of hardness, which are obtained using traditional methods. ...

Another object of the present invention is to provide an aluminum alloy plate product having improved fatigue resistance over AA7055 plate products.

Another goal is to provide structural elements for aerospace applications, such as wing tops, of an aluminum alloy plate product with improved fatigue resistance.

These and other objects and additional advantages are fulfilled or surpassed by the present invention, which provides a method for making a rolled plate product from an aluminum alloy having a final thickness or final gauge less than 75 mm, preferably less than 50 mm, ideal for use as a plate product for aerospace applications with improved fatigue resistance, the method comprising the following steps in the order indicated:

(a) casting an ingot from an aluminum alloy of the 7xxx series, the aluminum alloy containing (in wt%):

(b) homogenizing and / or preheating the cast ingot;

(c) hot rolling the ingot into a plate product by rolling the ingot in several rolling passes, wherein when the intermediate plate thickness is 80 to 220 mm, preferably 100 to 200 mm, at least one hot rolling pass is performed with a high degree of reduction with a decrease in thickness of at least 25%;

(d) optionally solution heat treatment and cooling to ambient temperature, preferably by quenching, the plate product;

(e) optionally stretching the solution heat treated plate product;

(f) optional artificial aging of the plate product.

The term "comprising" in the context of an aluminum alloy is to be understood in the sense that the alloy may contain additional alloying elements, as described below for example.

The method according to the present invention can be applied to a wide range of aluminum alloys of the 7xxx series, characterized by the following composition, in wt. %,

one or more elements selected from the group consisting of the following:

residue: aluminum and impurities. Typically, such impurities are present in an amount of <0.05% each, for a total of <0.15%.

In a further embodiment, the aluminum alloy has a chemical composition within the ranges of the AA7010, AA7040, AA7140, AA7449, AA7050, AA7150, AA7055, AA7255, AA7081, AA7181, AA7085, AA7185, AA7090, AA7099, AA7199 and modifications thereof.

In a specific embodiment, the aluminum alloy has a chemical composition within the ranges of the AA7055 series.

As will be described below, unless otherwise noted, aluminum alloy designations and hardness designations refer to the Aluminum Manufacturers Association designations in aluminum standards and data and registry entries published by the Aluminum Manufacturers Association in 2016 and are well known to the person skilled in the art. ...

For any description of alloy compositions or preferred alloy compositions, all references to percentages are by weight, unless otherwise indicated.

As used herein, the terms "≤" and "before" and "approximately before" explicitly contemplate, inter alia, the possibility of zero weight percent of the particular alloying component to which they refer. For example, up to 0.4% Cr may be a Cr-free alloy.

In the method according to the present invention, it is preferable not to carry out the cold rolling step of rolling the plate product to the final gauge (thickness) in order to avoid at least partial recrystallization during the subsequent solution heat treatment step, leading to a negative effect on the balance of technical properties in the final plate product. ...

The final thickness of the rolled plate product is less than 75 mm, preferably 50 mm, preferably less than 45 mm, more preferably less than 40 mm and most preferably less than 35 mm. In suitable embodiments, the final thickness of the plate product is greater than 10 mm, preferably greater than 12.5 mm, more preferably greater than 15 mm, and most preferably greater than 19 mm.

The aluminum alloy can be provided as a rolled ingot or slab using casting techniques known in the casting art, such as DC casting (direct chill casting), EMC casting (electromagnetic casting), EMS casting (electromagnetic stirring casting), and preferably has a thickness in the range of 300 mm or more, for example 400 mm, 500 mm or 600 mm. Less preferably, slabs obtained from continuous casting can also be used, for example in strip casters or roll casters, which, in particular, can be advantageous in the manufacture of finished products of a smaller caliber. It is also possible to use grain refining additives, for example containing titanium and boron or titanium and carbon, as is well known in the art. After casting the rolled alloy material, the surface layer is usually removed from the ingot to remove segregation zones near the casting surface of the ingot.

The rolled ingot is then subjected to homogenization and / or preheating.

It is known in the art that homogenization heat treatment has the following objectives: (i) to dissolve as much of the coarse soluble phases formed during solidification as possible, and (ii) to reduce concentration gradients to simplify the dissolution step. Preheating treatment also achieves some of these goals.

Typically, preheating refers to heating an ingot to a predetermined temperature and holding at that temperature for a predetermined time, followed by the initiation of hot rolling at approximately that temperature. Homogenization refers to a heating and cooling cycle applied to a rolled ingot in which the final temperature after homogenization is equal to the ambient temperature.

Typical preheat treatments for the AA7xxx series alloys used in the process of the present invention are carried out at temperatures from 400 ° C to 460 ° C with holding times ranging from 2 to 50 hours, typically 2-20 hours.

First, soluble eutectic phases such as S-phase, T-phase and M-phase in the alloy material are dissolved using standard industrial practice. This is usually done by heating the material to a temperature of less than 500 ° C, typically in the range of 450 ° C to 490 ° C, since the S-phase and the eutectic phase (Al ₂ MgCu phase) have a melting point of approximately 489 ° C in alloys of the AA7xxx series, and the M-phase (MgZn ₂ phase) has a melting point of approximately 478 ° C. As is known in the art, this can be achieved by homogenizing treatment in the specified temperature range and cooling to hot rolling temperature, or, after homogenizing, the material is then cooled and reheated before hot rolling. The conventional homogenization process can also be carried out in two or more steps, if necessary, which are usually carried out in the temperature range from 430 ° C to 490 ° C for AA7xxx series alloys. For example, in a two-stage process, the first stage is carried out in the temperature range from 455 ° C to 465 ° C, and the second stage is carried out in the temperature range from 470 ° C to 485 ° C to optimize the dissolution process of various phases depending on the exact composition of the alloy.

The holding time at homogenization temperature according to industrial practice depends on the alloy, as is well known to the skilled person, and is usually in the range of 1 to 50 hours. Heating rates that can be applied are common in the art.

Hot rolling of the ingot is carried out in several hot rolling passes, usually in a hot rolling mill. The number of hot rolling passes is generally 15 to 35, preferably 20 to 29. After the hot rolled plate reaches an intermediate thickness of 80 mm to 220 mm, preferably 100 mm to 200 mm, the method uses at least one pass hot rolling at a high reduction ratio with a thickness reduction of at least about 25%, preferably at least about 30%, and most preferably at least about 35%. In suitable embodiments, the thickness reduction in this high reduction pass is less than 70%, preferably less than 60%, more preferably less than 50%. The term "thickness reduction" in a rolling pass, also called a reduction ratio, preferably denotes the percentage by which the plate thickness is reduced in one rolling pass.

Such at least one high reduction hot rolling pass is not performed in conventional industrial hot rolling techniques for the manufacture of 7xxx series alloy plate products. Thus, hot rolling passes from 80 mm to 220 mm according to a non-limiting example of the present invention can be described as follows: (when looking at the intermediate plate thickness): 203 mm - 190 mm - 177 mm - 167 mm - 117 mm - 102 mm - 92 mm. A hot roll pass with a high reduction ratio of 167 mm to 117 mm corresponds to a thickness reduction of approximately 30%. For aluminum alloy plates produced by the traditional hot rolling process, the thickness reduction with each hot rolling pass is typically 9% to 18% when the intermediate thickness is 80 mm to 220 mm. Accordingly, hot rolling passes from 80 mm to 220 mm according to the examples of the conventional method can be described as follows (when looking at the intermediate plate thickness): 203 mm - 188 mm - 166 mm - 144 mm - 124 mm - 104 mm - 92 mm. Accordingly, the method of the present invention includes a hot rolling step in which at least one high reduction hot rolling pass is performed. This high reduction pass is characterized by a thickness reduction of at least about 25%, preferably at least about 30%, and most preferably at least about 35%.

The hot rolling passes in the method of the present invention before and after the high reduction pass have a reduction ratio that is comparable to the reduction ratio of the hot rolling passes in the conventional hot rolling method. Accordingly, each hot rolling pass before and after the high reduction hot rolling pass may have a thickness reduction of 8% to 18%. Since the values of the thickness reduction vary depending on the thickness of the plate, for example, in thick plates with a thickness of more than 300 mm or in thin plates with a thickness of less than 30 mm, a feature of the proposed method is that the stage with a high degree of reduction is carried out when the intermediate thickness of the plate product reaches a value from 220 mm to 80 mm, preferably from 200 mm to 100 mm, most preferably from 200 mm to 120 mm. This thickness is chosen so as to ensure a constant high deformation / shear throughout the thickness of the plate product. For plate products with a thickness of more than 220 mm, it is more difficult to ensure constant deformation throughout the plate. Typically, in thicker plate products, the deformation at the center (half the thickness) of the plate product will be less than at the quarter-thickness position or subsurface region.

Preferably, one pass of high reduction hot rolling is carried out. In an alternative embodiment, two high reduction hot rolling passes are performed. If one high reduction hot rolling pass is used, this high reduction hot rolling pass is preferably one of the last seven or eight passes of the plurality of hot rolling passes.

Before starting the hot rolling process, the rolled ingot is preheated to a temperature common in the art and known to the person skilled in the art, for example from 390 ° C to 480 ° C, preferably from 400 ° C to 460 ° C, most preferably from 400 ° C to 430 ° C, for example up to 410 ° C. Accordingly, the temperature at the entrance to the hot rolling mill can be kept above 380 ° C, preferably above 390 ° C. The maximum temperature for hot rolling passes is not more than 450 ° C, since it has been observed that coarsening of the S-phase can occur above this temperature and that there is a risk of starting melting.

It has been found that in the case of manufacturing a plate product having a final thickness of less than 50 mm, the deformation rate during the hot rolling process also has an effect on the properties of the final plate product. Thus, the strain rate during at least one pass with a high reduction ratio in a suitable embodiment of the method is preferably below <1 s-1, preferably ≤ 0.8 s-1. It is believed that this intense shear causes the destruction of constituent particles, for example, intermetallic compounds with a high Fe content.

The strain rate during hot rolling per rolling pass can be described using the following formula:

where

скорость деформации (в с^-1),

strain rate (in s ^-1) ,

h ₀ plate thickness at the entrance (in mm),

h ₁ output plate thickness (in mm),

v ₁ rolling speed of the work rolls (in mm / s),

R is the radius of the work rolls (in mm).

Strain rate is the change in stress (strain) of a material over time. It is sometimes also referred to as the "speed of propagation of mechanical stresses". This formula demonstrates that the deformation rate is influenced not only by the thickness at the entrance and the thickness at the exit of the aluminum alloy plate, but also by the rolling speed of the work rolls.

For traditional production-scale hot rolling techniques, the strain rate of each rolling pass is typically 2 s ^-1 or more. As mentioned above, according to an embodiment of the method according to the present invention, during the high reduction pass, the strain rate is reduced to <1 s ^-1 , preferably to ≤ 0.8 s ^-1 . By using a low strain rate, a more intense shear can be achieved in the plate material.

In addition, the aluminum alloy plate product made according to the present invention may, if necessary, be solution heat treated (SHT) cooled, preferably by quenching, stretching and artificial aging after the hot rolling step to the final gauge. If solution heat treatment (SHT) is carried out, the plate product must be heated, similarly to the homogenization heat treatment prior to hot rolling, to a temperature typically in the range of 430 ° C to 490 ° C, to convert all or substantially all parts of soluble zinc, magnesium and copper in solution. After the specified holding time at the elevated temperature has elapsed, the plate product must be rapidly cooled or quenched to complete the solution heat treatment procedure. Such quenching is preferably carried out by quenching in water, for example by immersion in water or water jets.

After cooling to ambient temperature, the plate products can be additionally subjected to cold deformation by stretching in the range from 0.5% to 8% of the original length to relieve residual stresses in them and improve the flatness of the product. Preferably, the elongation is in the range from 0.5% to 5%, more preferably from 1% to 3%.

In a preferred embodiment, the plate products obtained according to the present invention are artificially aged. All aging techniques that are known in the art and which may subsequently be developed can be applied to AA7000 series alloy products produced by the process of the present invention to provide the required strength and other technical properties.

In a particular preferred embodiment, the plate product is artificially aged to a T7 hardness, preferably to a T79 or T77 hardness. Artificial aging can be carried out in one step or in several steps. Preferably, a two-stage aging procedure is carried out.

The desired structural profile is then machined from these heat-treated plate sections, usually after artificial aging, for example a one-piece wing spar.

An advantage of the present invention is that the aluminum alloy product exhibits improved fatigue resistance without the need to keep the iron and silicon contents extremely low. According to the prior art, it is generally believed that Fe and Si adversely affect fatigue resistance. However, the aluminum alloy plate products made by the method of the present invention are much more resistant to the presence of Fe and Si while still providing the desired balance of properties, including high fatigue resistance. In an embodiment, the alloy may contain more than 0.05%, preferably more than 0.06% Fe. In an embodiment, it may contain more than 0.05%, preferably more than 0.06% Si. In a further preferred embodiment, the content of each of Fe and Si is 0.07 wt. % or more. In another embodiment, the Si content is from 0.06% to 0.10% and the Fe content is from 0.06% to 0.15%. Accordingly, for example, a commercially available AA7055 aluminum alloy may be used in the inventive method.

In other embodiments, Fe and Si are kept at very low levels to achieve further improvement in properties. For example, the Fe content can be kept less than 0.05%, preferably less than 0.03%, and the Si content can be less than 0.05%, preferably less than 0.03%.

The AA7000 series alloy plate product made according to the present invention can be used as a structural member for aerospace applications, inter alia, as a fuselage frame member, wing top plate, wing bottom plate, thick plate for machined parts, thin plate for stringers, spar member, rib member, floor beam member, and bulkhead member.

In a particular embodiment, an aluminum alloy plate product is used as a panel or wing member, more specifically as a top panel or wing member.

Accordingly, a plate product made according to the present invention provides improved properties over a plate product made according to conventional conventional methods for aluminum alloys of this type, otherwise the same dimensions and machined to the same degree of hardness.

Brief Description of Drawings

The embodiments of the present invention will be described as non-limiting examples, and comparative examples of the prior art will also be provided.

FIG. 1 is a graph showing the maximum net stress versus the number of cycles to failure for wafers obtained using the method of the present invention and those obtained using conventional methods.

FIG. 2 is a graph showing the average log fatigue life of plates produced using the method of the present invention and plates produced using conventional methods, with the lines connecting the data points being the average.

An example of implementation of the invention

The rolled ingots were obtained by DC casting from AA7055 aluminum alloy with the composition shown in Table 1.

The rolled ingots were approximately 400 mm thick. Homogenization of the ingots was carried out in a two-stage homogenization procedure at a temperature of 465 ° C (first stage) and 475 ° C (second stage), followed by cooling to ambient temperature. After removing the surface layer, the ingots were preheated to 410 ° C for hot rolling. Hot rolling was carried out in a hot rolling mill whose work rolls have a radius of approximately 575 mm. Batches A and B were processed in accordance with the present invention, i. E. both batches were subjected to a high reduction pass during the hot rolling process. During the high reduction rolling pass, batch A underwent a thickness reduction of about 30% (from 167 mm to 117 mm) and batch B underwent a thickness reduction of about 28% (from 165 mm to 118 mm). The rolling speed during this high reduction pass was approximately 25 m / min, giving a deformation rate of approximately 0.53 s ^-1 . Batches C, D and E were processed according to the conventional hot rolling method (thickness reduction from 9% to 18% for each hot rolling pass from 220 mm to 80 mm). The rolling speed during standard hot rolling passes was approximately 105 m / min, giving a strain rate of 1.61 s ^-1 (entry thickness 188 mm) to 2.27 s ^-1 (entry thickness 123 mm). Plate A was subjected to 27 hot rolling passes, with the high reduction pass being pass number 19. Plate B was subjected to 25 hot rolling passes, with the high reduction pass being pass number 17.

Plates A, C and E had a final thickness of 19 mm after the hot rolling process, and plates B and D had a final thickness of 25.4 mm after the hot rolling process. After hot rolling, all final thickness plates were solution heat treated at about 470 ° C., quenched and stretched by about 2%. The stage of artificial aging was used to bring the plate products to the T7951 state.

The fatigue test was carried out according to DIN EN 6072 using a single hole test piece having a stress concentration factor Kt of 2.3. The test pieces were 150 mm long, 30 mm wide and 3 mm thick with one 10 mm diameter hole. The hole was countersunk to a depth of 0.3 mm on each side. The test pieces were subjected to axial stress with a stress ratio (minimum load / maximum load) R = 0.1. The test frequency was 25 Hz, and the tests were carried out in air with high humidity (RH ≥ 90%). The individual results of these tests are shown in Table 2 and in FIG. 1 and 2. The lines in FIG. 2 represent interpolation over the calculated log mean data points.

FIG. 1 shows that the method of the present invention can significantly improve the fatigue life and thus the fatigue fracture resistance compared to AA7055 plates produced by conventional methods. For example, at an applied stress in the working section of 175 MPa, plate A has a service life of 470 421 cycles, which represents an improvement in the service life by a factor of 3.2 in comparison with the AA7055 alloy, i.e. alloys C and E, which have a durability of 142655 cycles. Accordingly, in the alloys prepared by the method of the present invention and having a final thickness of 19 mm, a durability of 200,000 cycles (see the log average curve in FIG. 2) corresponds to a maximum net stress of about 210 MPa for the present invention, compared to 175 MPa in the alloy. 7055 prepared according to a traditional standard process. This represents an improvement of more than 20% that an aircraft manufacturer can use to increase the design stresses of the aircraft, thereby reducing weight while maintaining the same aircraft inspection interval.

FIG. 2 shows the log average of batches A and B made using the method of the present invention compared to the log average of batches C, D and E made using the conventional method from the same alloy shown in FIG. 1, with the lines showing interpolation from the calculated log averages of the data. Looking at this figure, it becomes apparent that the method of the present invention leads to improved fatigue life compared to conventional methods using the same alloy composition.

The present invention is not limited to the previously described embodiments, which may vary widely within the scope of the present invention as defined by the following appended claims.

Claims (27)

1. A method of manufacturing a plate product from an aluminum alloy of the 7xxx series, the method comprising the following steps: (a) casting an ingot from an aluminum alloy of the 7xxx series, where the aluminum alloy, in wt. %: Zn 5-9 Mg 1-3 Cu 0-3 Fe up to 0.20 Si up to 0.15 Zr up to 0.5, preferably 0.03-0.20 Aluminum and impurities rest (b) homogenizing and / or preheating the cast ingot; (c) hot rolling the ingot into a plate product by rolling the ingot in several rolling passes, characterized in that when the intermediate plate thickness is 80 to 220 mm, at least one hot rolling pass is performed at a high reduction ratio with a decrease in thickness by at least 25%, wherein the deformation rate during at least one pass of hot rolling with a high reduction ratio is <1 s ^-1 , moreover, the plate product has a final thickness of less than 75 mm, preferably less than 50 mm. 2. The method according to claim 1, wherein the method further comprises the following steps: (d) solution heat treatment of the plate product; (e) cooling, preferably by quenching, the solution heat treated plate product; (f) optionally stretching the solution heat treated plate product and cooling, and (g) artificial aging of the plate product subjected to solution heat treatment and cooling. 3. A method according to claim 1 or 2, characterized in that the hot rolling pass with a high reduction ratio is performed with a thickness reduction of at least 30%, preferably at least 35%. 4. A method according to any one of claims. 1-3, characterized in that the deformation rate during the hot rolling pass with a high reduction ratio is ≤0.8 s ^-1 . 5. The method according to any one of claims. 1-4, characterized in that the intermediate plate thickness before the hot rolling pass with a high reduction ratio is from 100 mm to 200 mm, preferably from 120 mm to 200 mm. 6. The method according to any one of claims. 1-5, characterized in that the Si content and / or the Fe content in the aluminum alloy is 0.05 wt. % or more. 7. A method according to any one of claims. 1-6, characterized in that the aluminum alloy contains, wt%: Zn 5-9, preferably 5.5-8.5 Mg 1-3 Cu 0-3, preferably 0.3-3 Si up to 0.15, preferably up to 0.10 Fe up to 0.20, preferably up to 0.15 one or more elements selected from the group consisting of the following: Ti up to 0.3 Cr up to 0.4 Sc up to 0.5 Hf up to 0.3 Mn up to 0.4 V up to 0.4 Ag up to 0.5 Aluminum and impurities rest 8. The method according to any one of claims. 1-7, characterized in that the aluminum alloy has a composition corresponding to AA7055. 9. A method according to any one of claims. 1-8, characterized in that the final thickness of the plate product is less than 45 mm, preferably less than 40 mm, and more preferably less than 35 mm. 10. The method according to any one of claims. 1-9, characterized in that the final thickness of the plate product is more than 10 mm, preferably more than 12.5 mm, more preferably more than 15 mm and most preferably more than 19 mm. 11. The method according to any one of claims. 1-10, characterized in that in step (c) of the method, the temperature at the entrance to the hot rolling mill is more than 380 ° C, preferably more than 390 ° C. 12. The method according to any one of claims. 2-11, characterized in that the plate-like product is artificially aged until the hardness level T7 is reached, preferably until the hardness level T79 or T77 is reached. 13. A plate product made of an aluminum alloy, characterized in that it is made by means of a method according to any one of claims. 1-12. 14. Structural element for aerospace applications, made of a plate product from an aluminum alloy obtained using the method according to any one of paragraphs. 1-12. 15. The use of a plate product from an aluminum alloy made according to any one of paragraphs. 1-12 for the manufacture of a structural member for aerospace applications.

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