Method for manufacturing an aluminum alloy part

Abstract

An additive manufacturing method applied to the following aluminum alloy composition, in weight percentages: - at least one alloying element chosen from: Zr, Hf, Sc and Er, in a mass fraction of 0.01 to 1.60% each and in total; - Fe, in a mass fraction of 0.05 to 3.00%; - Cr, in a mass fraction of 0.50 to 4.00%; - Mg, in a mass fraction of 0.01 to 3.50%.

Description

[0001] DESCRIPTION

[0002] Title: PROCESS FOR MANUFACTURING AN ALUMINUM ALLOY PART

[0003] Technical field

[0004] The technical field of the invention is a method of manufacturing an aluminum alloy part, using an additive manufacturing technique.

[0005] Prior art

[0006] Since the 1980s, additive manufacturing techniques have been developing. They involve shaping a part by adding material, which is the opposite of machining techniques, which aim to remove material. Once limited to prototyping, additive manufacturing is now operational for mass-producing industrial products, including metal parts.

[0007] The term "additive manufacturing" is defined according to the French standard XP E67-001 as a "set of processes for manufacturing, layer by layer, by adding material, a physical object from a digital object". The ASTM F2792 standard (January 2012) also defines additive manufacturing. Different additive manufacturing methods are also defined and described in the ISO / ASTM 17296-1 standard. The use of additive manufacturing to produce an aluminum part with low porosity was described in document W02015 / 006447. The application of successive layers is generally carried out by applying a so-called filler material, then melting or sintering the filler material using an energy source such as a laser beam, electron beam, plasma torch or electric arc. Regardless of the additive manufacturing method applied, the thickness of each added layer is of the order of a few tens or hundreds of microns.

[0008] Other additive manufacturing methods can be used. Examples include, but are not limited to, the melting or sintering of a filler material in the form of a powder, for example, laser melting or sintering. Patent application US2017 / 0016096 describes a method for manufacturing a part by localized melting obtained by exposing a powder to an energy beam such as an electron beam or laser beam, the method also being called laser powder bed fusion, selective laser powder bed fusion or electron beam melting.

[0009] The person skilled in the art knows solutions which allow thermal stability of the mechanical properties, but which are not necessarily suitable for high temperatures (see for example patent application WO202 / 070451, which discloses an alloy comprising from 1 to 10% of Fe, from 1 to 10% of Cr and optionally up to 4% of Zr, Hf, Er, Sc and / or Ti).

[0010] The mechanical properties of aluminum parts obtained by additive manufacturing depend on the alloy forming the filler metal, and more precisely on its composition, as well as the heat treatments applied following the implementation of additive manufacturing.

[0011] The applicant has determined an alloy composition which, when used in an additive manufacturing process, makes it possible to obtain parts with remarkable mechanical performance, without it being necessary to implement heat treatments such as solution treatment and quenching.

[0012] According to a variant of the present invention, with a judicious choice of the addition elements, the applicant has identified aluminum alloy compositions intended for additive manufacturing processes making it possible to obtain both very good processability of the parts, in particular in processes of the laser powder bed fusion type, and excellent mechanical performance of the parts in service at high temperature, that is to say for temperatures greater than or equal to 200°C. The excellent mechanical performance of the parts in service can be obtained by maximizing the elastic limit of the parts at 200°C or at 250°C after a post-manufacturing heat treatment, for example from 1 h to 400°C. By way of illustration, the elastic limit Rp0.2 obtained can be greater than or equal to 165 MPa at 250°C.

[0013] Pure aluminum powders can be used as a reducing agent in solid aerospace propellant. Therefore, aluminum powders with more than 97% aluminum are generally considered dual-use goods (DUGs) in some countries, requiring export licenses. This classification represents a constraint that can hinder the commercialization of certain aluminum powders containing more than 97% aluminum intended for additive manufacturing processes, such as laser powder bed fusion. It therefore appears advantageous for the developed solution to contain less than 97% aluminum, i.e., more than 3% additive elements in total.

[0014] According to another variant of the present invention, with a judicious choice of the additive elements, the applicant has identified aluminum alloy compositions intended for additive manufacturing processes, in particular laser powder bed fusion, these compositions comprising more than 3% of additive elements in total and allowing good processability of the parts in the laser powder bed fusion process, while maximizing the mechanical performance of the parts in service. Presentation of the invention

[0015] A first subject of the invention is a method of manufacturing a part comprising a formation of successive metallic layers, superimposed on each other, each layer being formed by the deposition of a filler metal, the filler metal being subjected to an energy input so as to melt and to constitute, by solidifying, said layer, the method being characterized in that the filler metal is an aluminum alloy comprising the following alloying elements in mass percentages:

[0016] - at least one alloying element chosen from: Zr, Hf, Sc and Er, according to a mass fraction of 0.01 to 1.60%, preferably 0.03 to 1.50%, preferably 0.05 to 1.40%, preferably 0.10 to 1.30%, preferably 0.20 to 1.25%, preferably 0.30 to 1.20%, preferably 0.40 to 1.00%, preferably 0.50 to 0.90%, preferably 0.60 to 0.80% each and in total;

[0017] - Fe, in a mass fraction of 0.05 to 3.00%, preferably 0.10 to 3.00%, preferably 0.20 to 3.00%, preferably 0.30 to 3.00%, preferably 0.40 to 3.00%, preferably 0.50 to 2.90%, preferably 0.60 to 2.80%, preferably 0.70 to 2.70%, preferably 0.80 to 2.70%, preferably 0.90 to 2.60%, preferably 0.90 to 2.50%, preferably 0.90 to 2.40%, preferably 0.90 to 2.30%, preferably 0.90 to 2.20%, -

[0018] - Cr, according to a mass fraction of 0.50 to 4.00%, preferably 0.70 to 4.00%, preferably 1.00 to 4.00%, preferably 1.30 to 3.90%, preferably 1.50 to 3.80%, preferably 1.60 to 3.70%, preferably 1.70 to 3.60%, preferably 1.75 to 3.50%, preferably 1.75 to 3.40%, preferably 1.75 to 3.30%, preferably 1.75 to 3.20%, preferably 1.80 to 3.20%, preferably 1.90 to 3.20%, preferably 1.90 to 3.00%, preferably 1.90 to 2.50%, preferably 1.90 to 2.20%, -

[0019] - Mg, in a mass fraction of 0.01 to 3.50%, preferably 0.03 to 3.50%, preferably 0.05 to 3.50%, preferably 0.10 to 3.40%, preferably 0.20 to 2.50%, preferably 0.30 to 2.30%, preferably 0.40 to 2.10%, preferably 0.40 to 1.80%, preferably 0.50 to 1.80%, preferably 0.50 to 1.50%, preferably 0.50 to 1.20%, -

[0020] - optionally at least one alloying element chosen from: Mn, V and Ti according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, each and in total;- optionally Mo, according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, -;

[0021] - optionally If, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.20%, preferably less than or equal to 0.15%, preferably less than or equal to 0.10%;

[0022] - optionally Ni, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%;

[0023] - optionally at least one alloying element chosen from: Cu and Ag, according to a mass fraction of 0.05 to 1.40%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Cu; according to a mass fraction of 0.05 to 3.00%, preferably 0.10 to 2.00%, preferably 0.10 to 1.60%, preferably 0.10 to 1.50%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Ag and in total;

[0024] - optionally at least one alloying element chosen from: Zn and Li, according to a mass fraction of less than 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30% each and in total;

[0025] - optionally at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn, according to a mass fraction less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30%, even more preferably less than or equal to 0.10% each, and less than or equal to 2.00%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.30% in total;

[0026] - impurities: < 0.05% individually, and preferably < 0.15% in total; remainder aluminum.

[0027] Each layer can notably describe a pattern defined from a digital model.

[0028] According to one embodiment, the filler metal takes the form of a powder, the exposure of which to a beam of light or charged particles results in localized melting followed by solidification, so as to form a solid layer. According to another embodiment, the filler metal is derived from a filler wire, the exposure of which to a heat source, for example an electric arc, results in localized melting followed by solidification, so as to form a solid layer.

[0029] A second object of the invention is a metal part, obtained by a method according to the first object of the invention.

[0030] A third subject of the invention is a filler material, in particular a filler wire or a powder, intended to be used as a filler material in an additive manufacturing process, characterized in that it is made of an aluminum alloy, comprising the following alloying elements (mass percentages):

[0031] - at least one alloying element chosen from: Zr, Hf, Sc and Er, according to a mass fraction of 0.01 to 1.60%, preferably 0.03 to 1.50%, preferably 0.05 to 1.40%, preferably 0.10 to 1.30%, preferably 0.20 to 1.25%, preferably 0.30 to 1.20%, preferably 0.40 to 1.00%, preferably 0.50 to 0.90%, preferably 0.60 to 0.80% each and in total;

[0032] - Fe, in a mass fraction of 0.05 to 3.00%, preferably 0.10 to 3.00%, preferably 0.20 to 3.00%, preferably 0.30 to 3.00%, preferably 0.40 to 3.00%, preferably 0.50 to 2.90%, preferably 0.60 to 2.80%, preferably 0.70 to 2.70%, preferably 0.80 to 2.70%, preferably 0.90 to 2.60%, preferably 0.90 to 2.50%, preferably 0.90 to 2.40%, preferably 0.90 to 2.30%, preferably 0.90 to 2.20%, -

[0033] - Cr, according to a mass fraction of 0.50 to 4.00%, preferably 0.70 to 4.00%, preferably 1.00 to 4.00%, preferably 1.30 to 3.90%, preferably 1.50 to 3.80%, preferably 1.60 to 3.70%, preferably 1.70 to 3.60%, preferably 1.75 to 3.50%, preferably 1.75 to 3.40%, preferably 1.75 to 3.30%, preferably 1.75 to 3.20%, preferably 1.80 to 3.20%, preferably 1.90 to 3.20%, preferably 1.90 to 3.00%, preferably 1.90 to 2.50%, preferably 1.90 to 2.20%, - - Mg, in a mass fraction of 0.01 to 3.50%, preferably 0.03 to 3.50%, preferably 0.05 to 3.50%, preferably 0.10 to 3.40%, preferably 0.20 to 2.50%, preferably 0.30 to 2.30%, preferably 0.40 to 2.10%, preferably 0.40 to 1.80%, preferably 0.50 to 1.80%, preferably 0.50 to 1.50%, preferably 0.50 to 1.20%, -

[0034] - optionally at least one alloying element chosen from: Mn, V and Ti according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, each and in total;

[0035] - optionally Mo, according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, -

[0036] - optionally If, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.20%, preferably less than or equal to 0.15%, preferably less than or equal to 0.10%;

[0037] - optionally Ni, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%;

[0038] - optionally at least one alloying element chosen from: Cu and Ag, according to a mass fraction of 0.05 to 1.40%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Cu; according to a mass fraction of 0.05 to 3.00%, preferably 0.10 to 2.00%, preferably 0.10 to 1.60%, preferably 0.10 to 1.50%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Ag and in total;

[0039] - optionally at least one alloying element chosen from: Zn and Li, according to a mass fraction of less than 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30% each and in total;

[0040] - optionally at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn, according to a mass fraction less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30%, even more preferably less than or equal to 0.10% each, and less than or equal to 2.00%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.30% in total;

[0041] - impurities: < 0.05% individually, and in total < 0.15%; remainder aluminum.

[0042] The aluminum alloy forming the filler material may have the characteristics described in connection with the first subject of the invention.

[0043] The filler material may be in the form of a powder. The powder may be such that at least 80% of the particles comprising the powder have an average size in the following range: 5 to 200 pm, preferably 5 to 150 pm, preferably 5 to 25 pm, or 20 to 60 pm or 20 to 80 pm or 20 to 90 pm or 20 to 100 pm or 20 to 110 pm or 20 to 120 pm.

[0044] When the filler material is in the form of a wire, the diameter of the wire may in particular be from 0.5 mm to 3 mm, and preferably from 0.5 mm to 2 mm, and more preferably from 1 mm to 2 mm.

[0045] A fourth object of the invention is the use of a powder or a filler wire as described above and in the rest of the description in an additive manufacturing process chosen from: laser powder bed fusion, electron beam melting, cold spraying, laser fusion deposition, friction additive manufacturing, plasma spark sintering or rotary friction welding, preferably laser powder bed fusion.

[0046] Other advantages and characteristics will emerge more clearly from the following description of particular embodiments of the invention, given as non-limiting examples, and represented in the figures listed below.

[0047] Figures

[0048] Figure 1 is a schematic illustrating a laser powder bed fusion additive manufacturing process.

[0049] Figure 2 is a schematic diagram illustrating a wire arc additive manufacturing process.

[0050] Figure 3 is a schematic of the test piece used according to the examples.

[0051] Presentation of specific embodiments

[0052] In the description, unless otherwise indicated:

[0053] - the designation of aluminum alloys is in accordance with the nomenclature of The Aluminum Association;

[0054] - the chemical element contents are designated in % and represent mass fractions. The notation x% - y% means greater than or equal to x% and less than or equal to y%.

[0055] Impurities are chemical elements present in the alloy unintentionally, preferably in a mass fraction of less than 0.05%.

[0056] According to the present invention, the expression "at least one alloying element chosen from: X, Y (...) and Z" means that each of the elements cited may be present, alone or in combination with any one or any of the other elements, according to the specified mass fractions. This expression therefore covers each of the elements cited and all their possible combinations.

[0057] According to the present invention, the optional elements are:

[0058] - either absent, i.e. considered as an unintentional impurity according to a mass fraction of less than 0.05%,

[0059] - either present according to the specified mass fractions.

[0060] Figure 1 shows schematically the operation of an additive manufacturing process of the laser powder bed fusion type (or Laser Powder Bed Fusion). The filler metal 15 is in the form of a powder arranged on a support 10. An energy source, in this case a laser source 11, emits a laser beam 12. The laser source is coupled to the filler material by an optical system 13, the movement of which is determined according to a digital model M. The laser beam 12 propagates along a propagation axis Z, and follows a movement along an XY plane, describing a pattern depending on the digital model M. The plane is for example perpendicular to the propagation axis Z. The interaction of the laser beam 12 with the powder 15 causes a selective melting of the latter, followed by solidification, resulting in the formation of a layer 20i...20 n. When a layer has been formed, it is covered with powder 15 of the filler metal and another layer is formed, superimposed on the layer previously produced. The thickness of a layer can for example be from 10 to 250 pm, for example 30 pm, or 60 pm, or 80 pm, or 90 pm, or 100 pm, or 110 pm, or 120 pm, or 130 pm, or 140 pm, or 150 pm, or 160 pm, or 170 pm, or 180 pm, or 190 pm, or 200 pm.

[0061] An increase in layer thickness may be beneficial to increase productivity during printing and to limit sensitivity to thermal cracking related to residual stresses during part manufacturing and / or post-manufacturing heat treatment. An increase in layer thickness may be accompanied by an adaptation of the laser power and vector gap (distance between two successive laser passes) and laser scanning speed to ensure complete melting of each powder layer under optimal conditions. The layer thickness may be, for example, from 60 to 250 pm, preferably from 80 to 200 pm, preferably from 90 to 180 pm, preferably from 100 to 180 pm, preferably from 110 to 170 pm, preferably from 120 to 160 pm.

[0062] For aluminum alloys, the support 10 or platen can be heated to a preheating temperature T of up to 500°C. Machines currently available on the market generally offer platen heating up to 200°C. The platen heating temperature (= preheating temperature T) can be, for example, approximately 50°C, or 100°C, or 150°C, or 200°C, or 250°C, or 300°C, or 350°C, or 400°C, or 450°C, or 500°C. Heating the platen generally reduces the humidity in the powder bed and also reduces residual stresses on the parts being manufactured. The humidity level in the powder bed seems to have a direct effect on the porosity of the final part. Indeed, it seems that the higher the humidity of the powder, the higher the porosity of the final part. It should be noted that heating the plate is one of the existing possibilities for carrying out hot additive manufacturing.However, the present invention cannot be limited to the use of this heating means alone. Any other heating means, making it possible to carry out this preheating step, can be used within the scope of the present invention to heat and control the temperature, for example an infrared lamp. Thus, the method according to the present invention can be carried out at a preheating temperature T of up to 500°C. In the paragraphs above and below, the preheating temperature T can relate to the plate, the powder bed or the manufacturing enclosure. For certain compositions, the inventors have found that when the preheating temperature T, for example of the powder bed, is less than or equal to 160°C and greater than or equal to 25°C, the parts have better resistance to thermal cracking linked to residual stresses.Preferably, the preheating of the powder bed can be carried out at a preheating temperature T less than or equal to 140°C, or, more preferably, less than or equal to 130°C. The preheating temperature T is higher than ambient temperature. Preferred ranges of preheating temperature T of the powder bed are: 25°C < T < 160°C, preferably 30°C < T < 150°C, preferably 50°C < T < 150°C, preferably 50°C < T < 140°C, preferably 60°C < T < 140°C, preferably 70°C < T < 135°C, preferably 80°C < T < 130°C.

[0063] Alternatively, the preheating temperature T corresponds to the conditions under which effective stress relief can be achieved. The preheating temperature range T may then be from 300°C to 500°C, preferably from 300 to 400°C, preferably from 300 to 350°C. It is considered that at this preheating temperature range T, the manufacturing conditions of the part generate fewer residual stresses. According to this alternative, a post-manufacturing stress relief heat treatment, as described below in this description, is also relevant.

[0064] The powder according to the present invention may have at least one of the following characteristics:

[0065] - Average particle size from 5 pm to 200 pm, preferably from 5 to 150 pm, preferably from 5 to 25 pm, or from 20 to 60 pm, or from 20 to 80 pm, or from 20 to 90 pm, or from 20 to 100 pm, or from 20 to 110 pm, or from 20 to 120 pm, The given values ​​mean that at least 80% of the particles have an average size in the specified range.

[0066] - Spherical shape. The sphericity of a powder can, for example, be determined using a morphogranulometer.

[0067] - Good flowability. The flowability of a powder can, for example, be determined according to ASTM B213 or ISO 4490:2018. According to ISO 4490:2018, the flow time is preferably less than 50.

[0068] - Low porosity, preferably 0 to 5%, more preferably 0 to 2%, even more preferably 0 to 1% by volume. Porosity can be determined, in particular, by image analysis from optical micrographs or by helium pycnometry (see ASTM B923).

[0069] - Absence or low quantity (less than 10%, preferably less than 5% by volume) of small particles (1 to 20% of the average size of the powder), called satellites, which stick to the larger particles. The implementation of such a process allows the manufacture of parts with a high yield, which can reach or even exceed 200 cm 3 / h per laser.

[0070] Furthermore, the applicant observed that the application of post-manufacturing heat treatments such as quenching could cause distortion of the part, due to the sudden temperature variation. The distortion of the part is generally all the more significant as its dimensions are large. However, the advantage of an additive manufacturing process is precisely to obtain a part whose shape, after manufacturing, is definitive or quasi-definitive. The occurrence of significant deformation resulting from a post-manufacturing heat treatment is therefore to be avoided. By quasi-definitive, it is understood that finishing machining can be carried out on the part after its manufacturing: the part manufactured by additive manufacturing extends according to its definitive shape, apart from the finishing machining.

[0071] Having noted the above, the applicant sought an alloy composition, forming the filler material, making it possible to obtain acceptable mechanical properties and electrical or thermal conductivity, without requiring the application of heat treatments, subsequent to the formation of the layers, that is to say following the formation of the final part, which risk inducing distortion. This involves in particular avoiding heat treatments involving a sudden variation in temperature. Thus, the invention makes it possible to obtain, by additive manufacturing, a part whose mechanical properties, in particular in terms of elastic limit, and electrical or thermal conductivity, are satisfactory. Depending on the type of additive manufacturing process chosen, the filler material may be in the form of a wire or a powder.

[0072] The following elements can be used in aluminum alloy.

[0073] Zr, Hf, Sc and / or Er:

[0074] According to the present invention, at least one alloying element selected from: Zr, Hf, Sc and Er is present in the aluminum alloy in a mass fraction of 0.01 to 1.60%, preferably 0.03 to 1.50%, preferably 0.05 to 1.40%, preferably 0.10 to 1.30%, preferably 0.20 to 1.25%, preferably 0.30 to 1.20%, preferably 0.40 to 1.00%, preferably 0.50 to 0.90%, preferably 0.60 to 0.80% each and in total.In one embodiment, the mass fraction of at least one alloying element selected from: Zr, Hf, Sc and Er is greater than or equal to 0.01%, or 0.02%, or 0.04%, or 0.06%, or 0.08%, or 0.10%, or 0.12%, or 0.14%, or 0.16%, or 0.18%, or 0.20%, or 0.22%, or 0.24%, or 0.26%, or 0.28%, or 0.30%, or 0.32%, or 0.34%, or 0.36%, or 0.38%, or 0.40%, or 0.42%, or 0.44%, or 0.46%, or 0.48%, or 0.50%, or 0.52%, or 0.54%, or 0.56%, or 0.58%, or 0.60% each and in total, In one embodiment, the mass fraction of at least one alloying element selected from: Zr, Hf, Sc and Er is less than or equal to 1.60%, or 1.55%, or 1.50%, or 1.45%, or 1.40%, or 1.35%, or 1.30%, or 1.25%, or 1.20%, or 1.15%, or 1.10%, or 1.05%, or 1.00%, or 0.95%, or 0.90%, or 0.85%, or 0.80% each and in total.

[0075] According to a variant of the present invention, at least one alloying element chosen from: Zr, Hf, Sc and Er is present in the aluminum alloy in a mass fraction less than or equal to 0.65%, preferably from 0.01 to 0.60%, preferably from 0.05 to 0.50%, preferably from 0.10 to 0.45%, preferably from 0.15 to 0.40% each and in total.

[0076] According to another variant of the present invention, at least one alloying element chosen from: Zr, Hf, Sc and Er is present in the aluminum alloy in a mass fraction of 0.40% to 1.60%, preferably 0.50 to 1.50%, preferably 0.55 to 1.40%, preferably 0.60 to 1.30%, preferably 0.60 to 1.25%, preferably 0.60 to 1.20%, preferably 0.60 to 1.00%, preferably 0.60 to 0.95%, preferably 0.65 to 0.90% each and in total.

[0077] These elements have a high solubility in the as-manufactured state. Their addition can thus significantly lower the conductivity in the as-manufactured state. However, the addition of a post-manufacture heat treatment, for example at a temperature of 300 to 450°C, for durations of 0.5 to 10 hours, can significantly lower their solid solution contents by the formation of hardening dispersoids of the AI3X type (X = Zr or Hf or Sc or Er). The formation of these dispersoids during the heat treatment can simultaneously increase the hardness and the electrical conductivity compared to the as-manufactured state.

[0078] These elements can also help control the granular structure during laser melting by promoting the appearance of equiaxed grains.

[0079] Furthermore, the presence of at least one alloying element chosen from: Zr, Hf, Sc and Er in the alloy can confer good processability to the alloy, the term processability corresponding to the Anglo-Saxon designation "processability", qualifying the ability of an alloy to be shaped by an additive manufacturing process. This can result, at the level of a part manufactured by additive manufacturing, in a virtual absence of defects, such as solidification cracking, and low porosity.

[0080] Fe:

[0081] According to the present invention, the element Fe is present in the aluminum alloy in a mass fraction of 0.05 to 3.00%, preferably 0.10 to 3.00%, preferably 0.20 to 3.00%, preferably 0.30 to 3.00%, preferably 0.40 to 3.00%, preferably 0.50 to 2.90%, preferably 0.60 to 2.80%, preferably 0.70 to 2.70%, preferably 0.80 to 2.70%, preferably 0.90 to 2.60%, preferably 0.90 to 2.50%, preferably 0.90 to 2.40%, preferably 0.90 to 2.30%, preferably 0.90 to 2.20%. In one embodiment, the mass fraction of Fe is greater than or equal to 0.05%, or 0.10%, or 0.15%, or 0.20%, or 0.25%, or 0.30%, or 0.35%, or 0.40%, or 0.45%, or 0.50%, or 0.55%, or 0.60%, or 0.65%, or 0.70%, or 0.75%, or 0.80%, or 0.85%, or 0.90%.In one embodiment, the mass fraction of Fe is less than or equal to 3.00%, or 2.95%, or 2.90%, or 2.85%, or 2.80%, or 2.75%, or 2.70%, or 2.65%, or 2.60%, or 2.55%, or 2.50%, or 2.45%, or 2.40%, or 2.35%, or 2.30%, or 2.25%, or 2.20%.

[0082] This element can increase the mechanical strength of the alloy by solid solution and / or by dispersoids that can form during the manufacturing of the part or during post-manufacturing heat treatments. This element has low solubility in aluminum. The addition of this element increases the yield strength, but excessive addition of Fe, i.e. at contents greater than or equal to 3.00%, can lead to an increase in sensitivity to cracking and lower the elongation at break.

[0083] Cr:

[0084] According to the present invention, the element Cr is present in the aluminum alloy in a mass fraction of 0.50 to 4.00%, preferably 0.70 to 4.00%, preferably 1.00 to 4.00%, preferably 1.30 to 3.90%, preferably 1.50 to 3.80%, preferably 1.60 to 3.70%, preferably 1.70 to 3.60%, preferably 1.75 to 3.50%, preferably 1.75 to 3.40%, preferably 1.75 to 3.30%, preferably 1.75 to 3.20%, preferably 1.80 to 3.20%, preferably 1.90 to 3.20%, preferably 1.90 to 3.00%, preferably 1.90 to 2.50%, preferably from 1.90 to 2.20%. In one embodiment, the mass fraction of Cr is greater than or equal to 0.50%, or 0.55%, or 0.60%, or 0.65%, or 0.70%, or 0.75%, or 0.80%, or 0.85%, or 0.90%, or 0.95%, 1.00%, or 1.05%, or 1.10%, or 1.15%, or 1.20%, or

[0085] 1.25%, or 1.30%, or 1.35%, or 1.40%, or 1.45%, or 1.50%, or 1.55%, or 1.60%, or 1.65%, or 1.70%, or 1.75%, or 1.80%, or 1.85%, or 1.90%. In one embodiment, the mass fraction of Cr is less than or equal to 4.00%, or 3.95%, or 3.90%, or 3.85%, or 3.80%, or

[0086] 3.75%, or 3.70%, or 3.65%, or 3.60%, or 3.55%, or 3.50%, or 3.45%, or 3.40%, or 3.35%, or 3.30%, or 3.25%, or 3.20%, or 3.15%, or 3.10%, or 3.05%, or 3.00%, or 2.95 %, or 2.90%, or 2.85%, or 2.80%, or 2.75%, or 2.70%, or 2.65%, or 2.60%, or 2.55%, or 2.50%, or 2.45%, or 2.40%, or 2.35%, or 2.30%, or 2.25%, or 2.20%. This element can increase the mechanical strength of the alloy by solid solution and / or by dispersoids that can form during the manufacturing of the part or during post-manufacturing heat treatments. The addition of this element can increase the yield strength at room temperature and at high temperature, this effect being accentuated by the presence of Fe in the alloy. Thus a simultaneous addition of Cr and Fe can be advantageous to increase the mechanical strength at room temperature and at high temperature (temperature greater than or equal to 200°C).

[0087] Excessive addition of Cr, i.e. at mass fractions greater than or equal to 4.00%, or even 3.20%, or even 2.20%, can lead to an increase in sensitivity to cracking and lower the elongation at break.

[0088] Cr has a low diffusion coefficient in aluminum which can provide high thermal stability to the alloy.

[0089] Cr has a high solubility in aluminum and has a negative impact on conductivity. The use of this element is of interest for alloys targeting certain applications that do not require particular performance in terms of electrical or thermal conductivity but require high mechanical strength, such as structural parts, hydraulic blocks, etc.

[0090] Mg:

[0091] According to the present invention, the element Mg is present in the aluminum alloy in a mass fraction of 0.01 to 3.50%, preferably 0.03 to 3.50%, preferably 0.05 to 3.50%, preferably 0.10 to 3.40%, preferably 0.20 to 2.50%, preferably 0.30 to 2.30%, preferably 0.40 to 2.10%, preferably 0.40 to 1.80%, preferably 0.50 to 1.80%, preferably 0.50 to 1.50%, preferably 0.50 to 1.20%. In one embodiment, the mass fraction of Mg is greater than or equal to 0.01%, or 0.02%, or 0.03%, or 0.04%, or 0.06%, or 0.08%, or 0.10%, or 0.12%, or 0.14%, or 0.16%, or 0.18%, or 0.20%, or 0.22%, or 0.24%, or 0.26%, or 0.28%, or 0.30%, or 0.32%, or 0.34%, or 0.36%, or 0.38%, or 0.40%, or 0.42%, or 0.44%, or 0.46%, or 0.48%, or 0.50%.In one embodiment, the mass fraction of Mg is less than or equal to 3.50%, or 3.45%, or 3.40%, or 3.35%, or 3.30%, or 3.25%, or 3.20%, or 3.15%, or 3.10%, or 3.05%, or 3.00%, or 2.95%, or 2.90%, or 2.85%, or 2.80%, or 2.75%, or 2.70%, or 2.65%, or 2.60%, or 2.55%, or 2.50%, or 2.45%, or 2.40%, or 2.35%, or 2.30%, or 2.25%, or 2.20%, or 2.15%, or.

[0092] 2.10%, or 2.05%, or 2.00%, or 1.95%, or 1.90%, or 1.85%, or 1.80%, or 1.75%, or 1.70%, or 1.65%, or 1.60%, or 1.55%, or 1.50%, or 1.40%, or 1.30%, or 1.20%. This element can increase the mechanical strength of the alloy by solid solution. It can also, counter-intuitively, improve crack resistance. Excessive addition of this element, for example at contents greater than or equal to 3.5%, can degrade intergranular corrosion resistance, by the formation of the anodic phase P (Mg5Alg) at the grain boundaries. The formation of this phase can occur at room temperature and its formation can be accelerated at temperatures greater than or equal to 60°C.

[0093] Mg can also, counter-intuitively, increase mechanical properties, including elastic limit (Rp0.2) and tensile strength (Rm) when hot, for example at 200°C or 250°C. Adding Mg at well-controlled levels can also increase elongation at break when hot, for example at 200°C or 250°C.

[0094] This positive impact of the addition of Mg on the elongation at break seems all the more marked when:

[0095] - Equiaxed grains do not form an interconnected three-dimensional network;

[0096] - The surface fraction of equiaxed grains is less than 30%, preferably less than 20%, preferably less than 10%, preferably less than 5%;

[0097] - The equiaxed grains have an average diameter greater than or equal to 0.5 pm, preferably greater than or equal to 1 pm, preferably greater than or equal to 2 pm, preferably greater than or equal to 3 pm, preferably greater than or equal to 4 pm, preferably greater than or equal to 5 pm.

[0098] This element is sensitive to evaporation during laser melting, which can lead to the formation of fumes and instabilities in the melt pools. This evaporation must be taken into account when adjusting the Mg content in the powder according to the target Mg content on the part.

[0099] Mn, V and / or Ti:

[0100] According to the present invention, at least one alloying element chosen from: Mn, V and Ti may be present in the aluminum alloy in a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, each and at least one of the following: total.In one embodiment, the mass fraction of at least one alloying element selected from Mn, V and Ti is greater than or equal to 0.03%, or 0.05%, or 0.10%, or 0.15%, or 0.20%, or 0.25%, or 0.30%, or 0.35%, or 0.40%, each and in total, In one embodiment, the mass fraction of at least one alloying element selected from: Mn, V and Ti is less than or equal to 3.00%, or 2.90%, or 2.80%, or 2.70%, or 2.60%, or 2.50%, or 2.40%, or 2.30%, or 2.20%, or 2.10%, or 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, each and in total.

[0101] These elements can increase the mechanical strength of the alloy at room temperature and at high temperature by solid solution and / or by dispersoids which can form during the manufacturing of the part or during post-manufacturing heat treatments. These elements have a low diffusion coefficient in aluminum which makes it possible to offer high thermal stability to the alloy.

[0102] These elements have a high solubility in aluminum and have a negative impact on conductivity. The addition of these elements is of interest for alloys targeting certain applications that do not require particular performance in terms of electrical or thermal conductivity but which require high mechanical resistance, such as structural parts, hydraulic blocks, etc.

[0103] Excessive addition of these elements may increase the sensitivity of the alloy to cracking, so in one variant the content of these elements is kept below 3.00% each and in total.

[0104] Preferably, the aluminum alloy necessarily comprises at least one alloying element chosen from: Mn, V and Ti, under the conditions as defined above, and in particular according to the mass fractions as described above.

[0105] According to one variant, the aluminum alloy comprises, preferably consists of: 0.50 to 0.90% of at least one alloying element selected from Zr, Hf, Sc and Er, preferably Zr, each and in total; 0.90 to 2.20% of Fe; 0.90 to 3.20%, preferably 0.90 to 2.20% of Cr; 0.40 to 1.90%, preferably 0.40 to 1.80%, preferably 0.40 to 1.50% of Mg; 0.40 to 1.60% of at least one alloying element selected from Mn, V and Ti, preferably Mn and V, each and in total; optionally up to 0.20%, preferably up to 0.15%, preferably up to 0.10% of Si; preferably remaining aluminum and impurities.

[0106] Alternatively, Ti may be absent from the aluminium alloy, i.e. possibly present only as an impurity, in a mass fraction of less than 0.05%, preferably less than 0.03%. Mo:

[0107] According to the present invention, the element Mo may be present in the aluminum alloy in a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%.

[0108] In one embodiment, the mass fraction of Mo is greater than or equal to 0.03%, or 0.05%, or 0.10%, or 0.15%, or 0.20%, or 0.25%, or 0.30%, or 0.35%, or 0.40%. In one embodiment, the mass fraction of Mo is less than or equal to 3.00%, or 2.90%, or 2.80%, or 2.70%, or 2.60%, or 2.50%, or 2.40%, or 2.30%, or 2.20%, or 2.10%, or 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%.

[0109] This element can increase the mechanical strength of the alloy by solid solution and / or by dispersoids which can form during the manufacture of the part or during post-manufacturing heat treatments. This element has low solubility in aluminum. The addition of this element can increase the elastic limit, but an excessive addition of Mo, i.e. at contents greater than or equal to 3.00%, can lead to an increase in sensitivity to cracking and lower the elongation at break.

[0110] Sh

[0111] According to the present invention, the element Si may be present in the aluminum alloy in a mass fraction of less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%; in one embodiment, the Si content is less than or equal to 0.30%, preferably less than or equal to 0.20%, preferably less than or equal to 0.15%, preferably less than or equal to 0.10%. According to a variant, the element Si may be present in the aluminum alloy in a mass fraction of greater than or equal to 500 ppm, or greater than or equal to 0.10%, or greater than or equal to 0.15%.

[0112] In one embodiment, the mass fraction of Si is less than or equal to 3.00%, or 2.90%, or 2.80%, or 2.70%, or 2.60%, or 2.50%, or 2.40%, or 2.30%, or 2.20%, or 2.10%, or 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70%, or 0.60, or 0.50%, or 0.45%, or 0.40%, or 0.35%, or 0.30%, or 0.25%, or 0.20%, or 0.15%, or 0.10%. This element can increase the mechanical strength of the alloy by solid solution and / or by precipitates or dispersoids that can form during the manufacture of the part or during post-manufacturing heat treatments. This element can have a beneficial effect by lowering the sensitivity to cracking.

[0113] The addition of Si in the presence of Zr can lead to the formation of coarse AlZrSi phases which would limit the hardening power of Zr after heat treatment.

[0114] Neither :

[0115] According to the present invention, the element Ni may be present in the aluminum alloy in a mass fraction of less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%. According to a variant, the element Ni may be present in the aluminum alloy in a mass fraction of greater than or equal to 500 ppm, or greater than or equal to 0.10%, or greater than or equal to 0.15%, or greater than or equal to 0.20%, or greater than or equal to 0.30%, or greater than or equal to 0.40%.

[0116] In one embodiment, the mass fraction of Ni is less than or equal to 3.00%, or 2.90%, or 2.80%, or 2.70%, or 2.60%, or 2.50%, or 2.40%, or 2.30%, or 2.20%, or 2.10%, or 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70%, or 0.60%, or 0.50%.

[0117] This element can be used to increase the mechanical strength of the alloy by solid solution and / or by dispersoids that can form during the manufacturing of the part or during post-manufacturing heat treatments. This element has low solubility in aluminum. The addition of this element can harden the alloy without having a significant impact on the conductivity.

[0118] Cu and / or Ag:

[0119] According to the present invention, at least one alloying element chosen from: Cu and Ag may be present in the aluminum alloy in a mass fraction of 0.05 to 1.40%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Cu; according to a mass fraction of 0.05 to 3.00%, preferably 0.10 to 2.00%, preferably 0.10 to 1.60%, preferably 0.10 to 1.50%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Ag and in total.

[0120] In one embodiment, the mass fraction of at least one alloying element selected from: Cu and Ag is greater than or equal to 0.05%, or 0.06%, or 0.07%, or 0.08%, or 0.09%, or 0.10% each and in total. In one embodiment, the mass fraction of at least one alloying element chosen from: Cu and Ag is less than or equal to 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70% for Cu: less than or equal to 3.00%, or 2.90%, or 2.80%, or 2.70%, or 2.60%, or 2.50%, or 2.40%, or 2.30%, or 2.20%, or 2.10%, or 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70% for Ag and in total.

[0121] These elements can increase the mechanical resistance of the alloy by solid solution and / or by hardening precipitates which can form during the manufacture of the part or during post-manufacturing heat treatments.

[0122] According to one variant, Cu may be absent from the aluminum alloy, i.e. possibly present only as an impurity, in a mass fraction of less than 0.05%, preferably less than 0.03%.

[0123] Zn and / or Li:

[0124] According to the present invention, at least one alloying element chosen from: Zn and Li may be present in the aluminum alloy according to a mass fraction less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferentially less than or equal to 0.50%, more preferentially less than or equal to 0.30% each and in total. According to a variant, at least one alloying element chosen from: Zn and Li may be present in the aluminum alloy according to a mass fraction greater than or equal to 500 ppm, or greater than or equal to 0.10%, or greater than or equal to 0.20% each and in total.

[0125] In one embodiment, the mass fraction of at least one alloying element selected from: Zn and Li is less than 2.00%, or less than or equal to 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70%, or 0.60%, or 0.50%, or 0.40%, or 0.30% each and in total. In one embodiment, the mass fraction of at least one alloying element selected from: Zn and Li is greater than or equal to 500 ppm, or 0.06%, or 0.07%, or 0.08%, or 0.09%, or 0.10%, or 0.11%, or 0.12%, or 0.13%, or 0.14%, or 0.15%, or 0.16%, or 0.17%, or 0.18%, or 0.19%, or 0.20% each and in total.

[0126] These elements can increase the mechanical strength of the alloy by solid solution. However, these elements are sensitive to evaporation during laser melting, which can lead to the formation of fumes and instabilities of the melt pools. Excessive addition of these elements can significantly lower the electrical conductivity. Thus, according to one embodiment, the addition of these elements is preferably avoided.

[0127] According to one variant, Zn may be absent from the aluminum alloy, i.e. possibly present only as an impurity, in a mass fraction of less than 0.05%, preferably less than 0.03%.

[0128] Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and / or Sn:

[0129] According to the present invention at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn, may be present in the aluminum alloy in a mass fraction of less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30%, even more preferably less than or equal to 0.10% each, and less than or equal to 2.00%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.30% in total.According to a variant, at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn may be present in the aluminum alloy in a mass fraction greater than 100 ppm, or greater than 300 ppm, or greater than 500 ppm each and in total.

[0130] In one embodiment, the mass fraction of at least one alloying element selected from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn is less than or equal to 2.00%, or 1.90%, or 1.80%, or 1.70%, or 1.60%, or 1.50%, or 1.40%, or 1.30%, or 1.20%, or 1.10%, or 1.00%, or 0.90%, or 0.80%, or 0.70%, or 0.60%, or 0.50%, or 0.40%, or 0.30% each and in total, or less than or equal to 0.20% or 0.10% each. In one embodiment, the mass fraction of at least one alloying element selected from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn is greater than or equal to 100 ppm, or 200 ppm or 300 ppm or 400 ppm or 500 ppm each and in total.These elements can increase the mechanical resistance of the alloy by solid solution and / or by dispersoids or precipitates which can form during the manufacture of the part or during post-manufacturing heat treatments.

[0131] The addition of Ca may be of interest, particularly to limit the evaporation of Mg and to limit its oxidation on the surface of the liquid bath during the atomization step and during the laser fusion step on the powder bed.

[0132] Alternatively, B may be absent from the aluminum alloy, i.e. possibly present only as an impurity, in a mass fraction of less than 0.05%, preferably less than 0.03%, preferably less than 0.01%, preferably less than 0.005%. The method may include, following the formation of the layers, i.e. following the formation of the final part, an application of at least one heat treatment. This treatment is also called post-manufacturing heat treatment or post-treatment. The post-manufacturing heat treatment may be or include tempering or annealing. It may also include solution treatment and quenching, although these are preferred to be avoided. It may also include hot isostatic pressing.

[0133] According to a first variant, in order to favor the mechanical properties, the post-manufacturing heat treatment can be carried out:

[0134] - at a temperature T' above 400°C, in which case the duration of the post-manufacturing heat treatment is from 0.1 h to 50 h, preferably from 0.1 h to 10 h;

[0135] - or at a temperature T' between 300°C and 400°C, in which case the duration of the post-manufacturing heat treatment is between 0.1 h and 200 h.

[0136] According to a second variant, in order to favor the thermal or electrical conduction properties, the post-manufacturing heat treatment can be carried out at a temperature T' greater than or equal to 350°C or 400°C for a duration of 0.1 h to 200 h, so as to obtain optimal thermal or electrical conductivity.

[0137] According to another variant, two-stage post-manufacturing heat treatments can maximize electrical conductivity. These treatments consist of first performing a first stage at a temperature T'1 above 450°C for a duration of 0.1 h to 100 h, followed by a second stage at a temperature T'2 between 300°C and 450°C for a duration of 0.1 h to 200 h.

[0138] According to another variant, two-stage post-manufacturing heat treatments can maximize electrical conductivity and / or hardness. These treatments consist of first performing a first stage at a temperature T'1 below 380°C for a duration of 0.1 h to 200 h, followed by a second stage at a temperature T'2 between 380°C and 450°C for a duration of 0.1 h to 200 h.

[0139] According to another variant, three-stage post-manufacturing heat treatments can maximize electrical conductivity and / or hardness. These treatments consist of first performing a first stage at a temperature T'1 between 250°C and 450°C for a duration of 0.1 h to 200 h, followed by a second stage at a temperature T'2 above 450°C for a duration of 0.1 h to 100 h, followed by a third stage at a temperature T'3 between 250°C and 450°C for a duration of 0.1 h to 200 h.

[0140] Multi-level treatments with a number of levels greater than 3 can also be considered.

[0141] According to one embodiment, the method may comprise hot isostatic pressing (HIP). The HIP treatment may in particular improve the elongation properties and the fatigue properties. The hot isostatic pressing may be carried out before, after or instead of the post-manufacturing heat treatment. Advantageously, the hot isostatic pressing is carried out at a temperature of 250°C to 500°C and preferably 300°C to 450°C, at a pressure of 500 to 3000 bars and for a duration of 0.5 to 100 hours.

[0142] For some compositions and for some types of parts, delamination cracks may appear in areas of the part with high stress concentrations during post-manufacturing heat treatment of parts, when the latter is carried out in a standard furnace. The use of CIC treatment can prevent the appearance of these cracks.

[0143] Once the parts are loaded into a CIC furnace, applying pressure before the furnace starts heating can be advantageous to avoid delamination cracking. For example, the pressure can be increased to a value of 1500 to 3000 bar before heating starts.

[0144] According to an advantageous embodiment, the method does not include quenching following the formation of the layers, i.e. following the formation of the final part, or following the post-manufacturing heat treatment. Thus, preferably, the method does not include solution treatment steps followed by quenching.

[0145] The use of post-manufacturing heat treatment, with manufacturing carried out using an additive manufacturing process, can create stress-relieving conditions that eliminate residual stresses and precipitate hardening phases. This is also referred to as thermal stress relief. The inventors observed that it was preferable for the set temperature T' of the post-manufacturing heat treatment to be between 300°C and 500°C.

[0146] Possible heat treatment and / or hot isostatic pressing can in particular increase the hardness or elastic limit and the electrical conductivity of the product obtained. However, it should be noted that, generally, the higher the temperature, the more conductivity (electrical or thermal) is favored to the detriment of mechanical resistance.

[0147] According to one embodiment, in addition to the temperature T' of the post-manufacturing heat treatment, the temperature rise, initiating the post-manufacturing heat treatment, is preferably as rapid as possible. For example, during the temperature rise, the temperature rise rate AT' (usually designated by those skilled in the art as "heating rate" in °C per minute or in °C per second) is preferably greater than 5°C per minute or greater than 10°C per minute, or even preferably greater than 20°C per minute and more advantageously greater than 40°C per minute, and more advantageously greater than 100°C per minute. By temperature rise, we mean the temperature rise to which the part is subjected during the post-manufacturing heat treatment.It seems optimal that the temperature rise is instantaneous, that is to say that the manufactured part is subjected, from the start of the post-manufacturing heat treatment, to the set temperature T' of the post-manufacturing heat treatment. An instantaneous temperature rise can be obtained by placing the manufactured part in a hot furnace, already brought to the set temperature T', or by a rapid heating means such as a fluidized bed or molten salt bath. The temperature rise can also be ensured by induction heating.

[0148] For the same temperature rise outside the part, the temperature variation inside the part depends in particular on the heating medium (liquid or air or inert gas) as well as the shape of the part. In particular, the temperature in the thickness or at the surface of the part can be different. This is the reason why the temperature rise mentioned above corresponds to the temperature outside the part. The combination of a preheating temperature T, a post-manufacturing heat treatment temperature T' and a temperature rise rate AT', during the post-manufacturing heat treatment temperature rise, in the aforementioned value ranges, makes it possible to obtain parts with good resistance to thermal cracking.

[0149] According to another embodiment, suitable for structurally hardened alloys, solution treatment can be carried out followed by quenching and tempering of the formed part and / or hot isostatic pressing. In this case, hot isostatic pressing can advantageously replace solution treatment.

[0150] However, the method according to the invention is advantageous because it preferably does not require solution treatment followed by quenching. Solution treatment can have a detrimental effect on mechanical strength in certain cases by contributing to a coarsening of the dispersoids or fine intermetallic phases. Preferably, the method according to the present invention does not involve solution treatment and / or quenching following the formation of the layers, i.e. following the formation of the final part, or following the post-manufacturing heat treatment.

[0151] According to one embodiment, the method according to the present invention further optionally comprises a machining treatment, and / or a chemical, electrochemical or mechanical surface treatment, and / or a tribofinishing. These treatments can be carried out in particular to reduce roughness and / or improve corrosion resistance and / or improve resistance to the initiation of fatigue cracks.

[0152] Optionally, it is possible to carry out mechanical deformation of the part, for example after additive manufacturing and / or before heat treatment.

[0153] Although described in connection with a powder bed laser fusion type additive manufacturing method, the method can be applied to other additive manufacturing methods such as wire plus arc additive manufacturing, mentioned in connection with the prior art. Figure 2 represents such an alternative. An energy source 31, in this case a torch, forms an electric arc 32. In this device, the torch 31 is held by a welding robot 33. The part 20 to be manufactured is arranged on a support 10. In this example, the manufactured part is a wall extending along a transverse axis Z perpendicular to an XY plane defined by the support 10. Under the effect of the electric arc 32, a filler wire 35 melts to form a weld bead. The welding robot is controlled by a digital model M. It is moved so as to form different layers 20i...20 n, stacked on top of each other, forming the wall 20, each layer corresponding to a weld bead. Each layer 20i...20 n extends in the XY plane, according to a pattern defined by the digital model M.

[0154] The diameter of the filler wire is preferably less than 3 mm. It can be between 0.5 mm and 3 mm and is preferably between 0.5 mm and 2 mm, or even between 1 mm and 2 mm. For example, it is 1.2 mm.

[0155] Other processes than laser powder bed fusion are also possible, for example, and without limitation: - selective laser sintering;

[0156] - direct metal laser sintering;

[0157] - selective heat sintering;

[0158] - electron beam melting;

[0159] - laser melting deposition;

[0160] - direct energy deposition;

[0161] - direct metal deposition;

[0162] - direct laser deposition;

[0163] - Laser Deposition Technology;

[0164] - laser net shaping engineering;

[0165] - laser cladding technology;

[0166] - Laser Freeform Manufacturing Technology;

[0167] - laser metal deposition;

[0168] - cold spray (Cold Spray Consolidation);

[0169] - additive manufacturing by friction (Additive Friction Stir);

[0170] - spark plasma sintering or flash sintering (Field Assisted Sintering Technology or spark plasma sintering); or

[0171] - Inertia Rotary Friction Welding.

[0172] Preferably, the part according to the present invention has a grain structure such that the surface fraction of columnar grains is greater than 60%, preferably greater than 70%, preferably greater than 80%, preferably greater than 90%, preferably greater than 95%.

[0173] Preferably, the part according to the present invention has at least one of the following characteristics:

[0174] - A value of Rp0.2 at 250°C for a deformation rate of 5xl0 -3 min 1greater than or equal to 165 MPa, preferably greater than or equal to 170 MPa, preferably greater than or equal to 175 MPa, preferably greater than or equal to 180 MPa, preferably greater than or equal to 185 MPa, preferably greater than or equal to 190 MPa;

[0175] - A value of Rp0.2 at 250°C for a deformation rate of 10 -5 s 1 greater than or equal to 160 MPa, preferably greater than or equal to 165 MPa, preferably greater than or equal to 170 MPa, preferably greater than or equal to 175 MPa, preferably greater than or equal to

[0176] 180 MPa. The solutions according to the present invention are particularly suitable for applications in the electrical, electronic and heat exchanger fields.

[0177] The invention will be explained in more detail in the examples below, which are given for illustrative and non-limiting purposes.

[0178] Experimental examples

[0179] Example 1

[0180] A study was conducted on six alloys (A, B, C, D, E, F), whose compositions, determined by ICP (Inductively Coupled Plasma) in mass percentages, are shown in Table 1 below. These six alloys were obtained in powder form using gas jet atomization (N2). The particle size of the different powders was essentially 3 pm to 120 pm, D10 was 26 to 33 pm, D50 was 47 to 58 pm and D90 was 81 to 93 pm.

[0181] [Table 1]

[0182] Using an EOSM290 laser powder bed fusion machine (EOS supplier), cylindrical samples vertical to the build direction (Z direction) were produced to determine the mechanical characteristics of the alloys. These samples had a diameter of 11 mm and a height of 46 mm. When printing these samples, the main laser parameters used were: laser power of 370 W; scanning speed of 1300 mm / s; vector gap of 0.14 mm; layer thickness of 60 μm. The heating temperature of the build plate was 100°C. All samples underwent a post-manufacturing heat treatment of 1 hour at 400°C with direct firing at 400°C.

[0183] The cylindrical samples were machined to obtain tensile specimens with the following characteristics as described in Table 2 below and Figure 3.

[0184] [Table 2] Tl

[0185] In Table 2 above and Figure 3, 0 represents the diameter of the central part of the specimen; M the width of the two ends of the specimen; LT the total length of the specimen; R the radius of curvature between the central part and the ends of the specimen; Le the length of the central part of the specimen and F the length of the two ends of the specimen.

[0186] All the specimens were tested in hot tension at 250°C. Some of the specimens were tested according to standard NF EN ISO 6892-2 (2018), with a strain rate of 5x10" 3 min -1 up to 1% plastic deformation, then 5xl0 -2 min _1 until the specimen ruptures (this test condition is called "fast speed" in the following description). The other part of the specimens was tested with a constant strain rate of 10 -5s _1 until the specimen breaks (this test condition is called “slow speed” in the rest of the description). The main results obtained are presented in Table 3 below.

[0187] [Table 3]

[0188] Table 4 below highlights the positive effect of the addition of Mg on tensile performance at 250°C. Each alloy in the first column of Table 4 is compared in the second column to a reference of the same composition but which does not contain Mg. The results in Table 4 show that for all the compositions tested and whatever the chosen strain rate (fast rate or slow rate), the addition of a Mg content between 0.80 and 1.00% made it possible to simultaneously increase the values ​​of Rp0.2 (yield limit), Rm (breaking strength) and A% (elongation at break). This result is counter-intuitive because an increase in the yield limit or breaking strength of a material is generally accompanied, according to the knowledge of the person skilled in the art, by a decrease in the elongation at break.The simultaneous increase in yield strength, breaking strength and elongation at break at 250°C obtained by adding an Mg content between 0.80 and 1.00% thus appears very advantageous and surprising. Furthermore, the positive effect of adding Mg to aluminum alloys on mechanical performance at temperatures greater than or equal to 200°C, as is the case in the present invention, is not known.

[0189] [Table 4]

[0190] Example 2

[0191] A study similar to that of Example 1 was carried out on two alloys (G and H). The compositions, determined by ICP (Inductively Coupled Plasma) in mass percentages, are shown in Table 5 below. These two alloys were obtained in powder form using gas jet atomization (N2). The particle size of the different powders was essentially 3 pm to 120 pm, D10 was 26 to 33 pm, D50 was 47 to 58 pm and D90 was 81 to 93 pm.

[0192] [Table 5]

[0193] From alloys G and H, specimens were manufactured and tested in tension at 250°C under the same conditions as those described in example 1.

[0194] The main results obtained are presented in Table 6 below. [Table 6]

[0195] Table 7 below highlights the effect on tensile performance at 250°C of the additional addition of an Mg content of 0.80 to 1.00% compared to a reference which already contains between 0.80 and 1.00% Mg.

[0196] Comparison of alloy H with alloy D shows that for a tensile test at 250°C:

[0197] - At high speed, the addition of 0.90% Mg to an alloy already containing 0.90% Mg showed a positive impact on Rp0.2 and Rm, but slightly degraded the elongation at break.

[0198] - At slow speed, the addition of 0.90% Mg to an alloy already containing 0.90% Mg showed a very low impact on Rp0.2 (+3.2 MPa) and Rm (-2 MPa) and lowered the elongation at break (-1.1%).

[0199] Comparison of alloy G with alloy B shows that for a tensile test at 250°C:

[0200] - At high speed, the addition of 0.85% Mg to an alloy already containing 0.85% Mg showed a negative impact on Rp0.2 and Rm, but improved elongation at break.

[0201] - At slow speed, the addition of 0.85% Mg to an alloy already containing 0.85% Mg showed a negative impact on Rp0.2 and Rm and showed a small impact on elongation at break (-0.3%).

[0202] These results showed that an excessive increase in Mg content to contents greater than or equal to 2.50%, and preferably greater than or equal to 2.00%, does not seem beneficial on the yield strength (Rp0.2) / elongation at break (A%) compromise at 250°C. The negative impact was more pronounced when the Cr content of the alloy was 2.90% (comparison between alloys G and B), than when the Cr content of the alloy was 2.00% (comparison between alloys H and D). [Table 7]

[0203] Example 3

[0204] Specimens similar to those described in Examples 1 and 2 were made from alloys D, E, F and H.

[0205] These specimens were tested in hot tension at 200°C according to standard NF EN ISO 6892-2 (2018), with a deformation rate of 5xl0 -3 min _1 up to 1% plastic deformation, then 5xl0 -2 min _1 until the specimen breaks (called “fast speed” in the rest of the presentation). The main results obtained are presented in Table 8 below.

[0206] [Table 8]

[0207] Table 9 below highlights the positive effect of adding Mg on tensile performance at 200°C.

[0208] Comparison of alloy F with alloy E showed that, at high speed, the addition of 0.90% Mg content simultaneously increased the values ​​of Rp0.2 (yield strength), Rm (breaking strength) and A% (elongation at break). This result is counter-intuitive and confirms the result previously observed for a tensile temperature of 250°C. It should be noted that, at 200°C, the addition of 0.90% Mg led to a greater increase in Rp0.2 (yield strength) and Rm (breaking strength) than what was observed in Example 1, comparing the tensile performances of the same two alloys at 250°C.

[0209] The comparison between alloys H and D showed that the additional addition of 0.90% Mg to a reference already containing 0.90% Mg allowed to simultaneously increase the values ​​of Rp0.2 (yield strength), Rm (breaking strength) and A% (elongation at break) at 250°C. It is worth noting that at 200°C, the addition of 0.90% Mg led to a greater increase in Rp0.2 (yield strength) and Rm (breaking strength) than what was observed at 250°C in Example 2, when comparing the tensile performances of the same two alloys.

[0210] [Table 9]

[0211] Example 4

[0212] Similar specimens to those in Example 1 were manufactured from the 5 alloys (F, H, I, J and K). The compositions, determined by ICP (Inductively Coupled Plasma) in mass percentages, are shown in Table 10 below. These five alloys were obtained in powder form using gas jet atomization (N 2). The particle size was essentially 3 pm to 120 pm, D10 was 26 to 33 pm, D50 was 47 to 58 pm and D90 was 81 to 93 pm.

[0213] [Table 10]

[0214] Characterizations of the grain structure were performed on an alloy sample in EBSD (Electron Back Scattered Diffraction) using an EDAX camera and OIM (Orientation Imaging Microscopy) software. These characterizations were performed using a ZEISS Ultra 55 SEM-FEG with an energy of 15keV, a working distance of 14 mm and a magnification (xl75), with a step size of 0.5 pm and an analysis area of ​​0.293 mm 2 (0.6125 mm x 0.4785 mm) parallel to the Z manufacturing direction of the sample. Grain boundaries were defined with a misorientation angle greater than or equal to 15°.

[0215] Prior to EBSD characterization, all samples underwent conventional mechanical polishing (abrasive paper with water lubrication then polishing cloths with diamond suspension) up to 1 pm, followed by vibration polishing with 30% amplitude for 6 hours, using a 50% dilution of SPM (colloidal silica gel) in water as lubricant.

[0216] Alloys K and J exhibited a completely columnar structure. Alloys F and H exhibited a bimodal grain structure with equiaxed grains at the bottom of the melt pools and a columnar structure in the center of the melt pools. This result showed, in a counterintuitive manner, that the partial replacement of 1% Mn by 1% Mg (comparison between alloys K and F) or the complete replacement of 2% Mn by 1.8% Mg (comparison between alloys K and H), led to a significant change in the grain structure.

[0217] Alloy I exhibited a completely columnar structure. This result showed that replacing 1% Mn with 1% V (comparison between alloys I and F), despite the presence of 0.9% Mg in the alloy, allowed to maintain a completely columnar grain structure. This counterintuitive result showed that in the presence of 0.9% Mg in the alloy, the addition of 1% V allowed to annihilate the refining effect of Mg.

[0218] Across all 5 alloys (F, H, I, J and K), the number of grains per mm 2 has been calculated.

[0219] The same analysis surface as described above was used. Grains touching the edge of the analysis surface were counted. The results are summarized in Table 11 below.

[0220] The comparison between alloys F and I showed that in the presence of a Mg content of 0.9% in the alloy, the replacement of 1% of Mn by 1% of V allowed to significantly reduce the number of grains per mm 2 , which went from 30881 to 3271 respectively.

[0221] Comparison between F and H alloys showed that replacing 1% Mn with 0.9% Mg increased the number of grains per mm 2 , which increased from 30881 to 36693 respectively.

[0222] Alloys I, J and K showed a low number of grains per mm 2 (between 3000 and 4500). Among these alloys were the alloys containing no Mg (J and K) and alloy I which contained a combination of 0.9% Mg and 1% V addition.

[0223] Alloys F and H exhibited a large number of grains per mm 2 (between 30000 and 37000). These two alloys had an addition of Mg not combined with an addition of V.

[0224] [Table 11] The results described above showed that controlling the Mg and V contents of the alloy made it possible, for a given Zr content of the alloy, to control the grain structure and thus to optimize the grain structure according to the intended final application. For an application requiring increased creep resistance, completely columnar structures would be preferred. However, for other applications, for example applications requiring a good compromise between mechanical properties at room temperature and at high temperature, a bimodal structure could be sought.

[0225] For a given manufacturing parameter and plate temperature, the judicious choice of the Zr, Mg and V contents of the alloy made it possible to control the granular structure of parts printed by additive manufacturing.

Claims

CLAIMS 1. Method for manufacturing a part (20) comprising a formation of successive metal layers (20i...20 n ), superimposed on each other, each layer being formed by the deposition of a filler metal (15, 35), the filler metal being subjected to an energy input so as to melt and to constitute, by solidifying, said layer, the method being characterized in that the filler metal (15, 35) is an aluminum alloy comprising the following alloying elements (mass percentages): - at least one alloying element chosen from: Zr, Hf, Sc and Er, according to a mass fraction of 0.01 to 1.60%, preferably 0.03 to 1.50%, preferably 0.05 to 1.40%, preferably 0.10 to 1.30%, preferably 0.20 to 1.25%, preferably 0.30 to 1.20%, preferably 0.40 to 1.00%, preferably 0.50 to 0.90%, preferably 0.60 to 0.80% each and in total; - Fe, in a mass fraction of 0.05 to 3.00%, preferably 0.10 to 3.00%, preferably 0.20 to 3.00%, preferably 0.30 to 3.00%, preferably 0.40 to 3.00%, preferably 0.50 to 2.90%, preferably 0.60 to 2.80%, preferably 0.70 to 2.70%, preferably 0.80 to 2.70%, preferably 0.90 to 2.60%, preferably 0.90 to 2.50%, preferably 0.90 to 2.40%, preferably 0.90 to 2.30%, preferably 0.90 to 2.20%, - - Cr, according to a mass fraction of 0.50 to 4.00%, preferably 0.70 to 4.00%, preferably 1.00 to 4.00%, preferably 1.30 to 3.90%, preferably 1.50 to 3.80%, preferably 1.60 to 3.70%, preferably 1.70 to 3.60%, preferably 1.75 to 3.50%, preferably 1.75 to 3.40%, preferably 1.75 to 3.30%, preferably 1.75 to 3.20%, preferably 1.80 to 3.20%, preferably 1.90 to 3.20%, preferably from 1.90 to 3.00%, preferably from 1.90 to 2.50%, preferably from 1.90 to 2.20%; - Mg, in a mass fraction of 0.01 to 3.50%, preferably 0.03 to 3.50%, preferably 0.05 to 3.50%, preferably 0.10 to 3.40%, preferably 0.20 to 2.50%, preferably 0.30 to 2.30%, preferably 0.40 to 2.10%, preferably 0.40 to 1.80%, preferably 0.50 to 1.80%, preferably 0.50 to 1.50%, preferably 0.50 to 1.20%; - optionally at least one alloying element chosen from: Mn, V and Ti according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, each and in total; - optionally Mo, according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, - - optionally If, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.20%, preferably less than or equal to 0.15%, preferably less than or equal to 0.10%; - optionally Ni, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%; - optionally at least one alloying element chosen from: Cu and Ag, according to a mass fraction of 0.05 to 1.40%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Cu; according to a mass fraction of 0.05 to 3.00%, preferably 0.10 to 2.00%, preferably 0.10 to 1.60%, preferably 0.10 to 1.50%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Ag and in total; - optionally at least one alloying element chosen from: Zn and Li, according to a mass fraction of less than 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30% each and in total; - optionally at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn, according to a mass fraction less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30%, even more preferably less than or equal to 0.10% each, and less than or equal to 2.00%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.30% in total; - impurities: < 0.05% individually, and preferably < 0.15% in total; remainder aluminum.

2. Method according to claim 1, characterized in that the aluminum alloy necessarily comprises at least one alloying element chosen from: Mn, V and Ti according to the mass fractions described.

3. The method of claim 1 or 2, wherein the aluminum alloy comprises, preferably consists of: 0.50 to 0.90% of at least one alloying element selected from Zr, Hf, Sc and Er, preferably Zr, each and in total; 0.90 to 2.20% of Fe; 0.90 to 3.20%, preferably 0.90 to 2.20% of Cr; 0.40 to 1.90%, preferably 0.40 to 1.80%, preferably 0.40 to 1.50% of Mg; 0.40 to 1.60% of at least one alloying element selected from Mn, V and Ti, preferably Mn and V, each and in total; optionally up to 0.20%, preferably up to 0.15%, preferably up to 0.10% of Si; preferably remains aluminum and impurities.

4. Method according to any one of the preceding claims, in which the part has at least one of the following characteristics: A value of RpO.2 at 250°C for a strain rate of 5xl0 -3 min 1 greater than or equal to 165 MPa, preferably greater than or equal to 170 MPa, preferably greater than or equal to 175 MPa, preferably greater than or equal to 180 MPa, preferably greater than or equal to 185 MPa, preferably greater than or equal to 190 MPa; A value of RpO.2 at 250°C for a strain rate of 10 -5 s 1 greater than or equal to 160 MPa, preferably greater than or equal to 165 MPa, preferably greater than or equal to 170 MPa, preferably greater than or equal to 175 MPa, preferably greater than or equal to 180 MPa.

5. A method according to any preceding claim, wherein the mass fraction of aluminum is less than 97%.

6. Method according to any one of the preceding claims, comprising, following the formation of the layers (20i...20 n ), that is to say following the formation of the final part, a application of post-manufacturing heat treatment, preferably tempering or annealing.

7. Method according to any one of the preceding claims, not comprising solution treatment and / or quenching following the formation of the layers, i.e. following the formation of the final part, or following the post-manufacturing heat treatment.

8. Method according to any one of the preceding claims, characterized in that it is carried out at a preheating temperature T of up to 500°C.

9. A method according to any preceding claim, wherein the filler metal takes the form of a powder (15), the exposure of which to a beam of light (12) or charged particles results in localized melting followed by solidification, so as to form a solid layer (20i...20 n ).

10. A method according to any one of claims 1 to 8, in which the filler metal is derived from a filler wire (35), the exposure of which to a heat source (32) results in localized melting followed by solidification, so as to form a solid layer (20i...20 n ).

11. Metal part obtained by a process which is the subject of any one of the preceding claims.

12. Powder, intended to be used as a filler material in an additive manufacturing process, characterized in that it consists of an aluminum alloy, comprising the following alloying elements (mass percentages): - at least one alloying element chosen from: Zr, Hf, Sc and Er, according to a mass fraction of 0.01 to 1.60%, preferably 0.03 to 1.50%, preferably 0.05 to 1.40%, preferably 0.10 to 1.30%, preferably 0.20 to 1.25%, preferably 0.30 to 1.20%, preferably 0.40 to 1.00%, preferably 0.50 to 0.90%, preferably 0.60 to 0.80% each and in total; - Fe, in a mass fraction of 0.05 to 3.00%, preferably 0.10 to 3.00%, preferably 0.20 to 3.00%, preferably 0.30 to 3.00%, preferably 0.40 to 3.00%, preferably 0.50 to 2.90%, preferably 0.60 to 2.80%, preferably 0.70 to 2.70%, preferably 0.80 to 2.70%, preferably 0.90 to 2.60%, preferably 0.90 to 2.50%, preferably 0.90 to 2.40%, preferably 0.90 to 2.30%, preferably 0.90 to 2.20%, - - Cr, according to a mass fraction of 0.50 to 4.00%, preferably 0.70 to 4.00%, preferably 1.00 to 4.00%, preferably 1.30 to 3.90%, preferably 1.50 to 3.80%, preferably 1.60 to 3.70%, preferably 1.70 to 3.60%, preferably 1.75 to 3.50%, preferably 1.75 to 3.40%, preferably 1.75 to 3.30%, preferably 1.75 to 3.20%, preferably 1.80 to 3.20%, preferably 1.90 to 3.20%, preferably 1.90 to 3.00%, preferably 1.90 to 2.50%, preferably 1.90 to 2.20%; - Mg, in a mass fraction of 0.01 to 3.50%, preferably 0.03 to 3.50%, preferably 0.05 to 3.50%, preferably 0.10 to 3.40%, preferably 0.20 to 2.50%, preferably 0.30 to 2.30%, preferably 0.40 to 2.10%, preferably 0.40 to 1.80%, preferably 0.50 to 1.80%, preferably 0.50 to 1.50%, preferably 0.50 to 1.20%; - optionally at least one alloying element chosen from: Mn, V and Ti according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%, each and in total; - optionally Mo, according to a mass fraction greater than or equal to 0.03%, preferably greater than or equal to 0.05%, preferably from 0.10 to 3.00%, preferably from 0.20 to 2.50%, preferably from 0.30 to 2.40%, preferably from 0.40 to 2.30%, preferably from 0.40 to 2.20%, preferably from 0.40 to 2.10%, preferably from 0.40 to 2.00%, preferably from 0.40 to 1.90%, preferably from 0.40 to 1.80%, preferably from 0.40 to 1.70%, preferably from 0.40 to 1.60%, preferably from 0.40 to 1.20%; - optionally If, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.20%, preferably less than or equal to 0.15%, preferably less than or equal to 0.10%; - optionally Ni, according to a mass fraction less than or equal to 3.00%, preferably less than or equal to 2.50%, preferably less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%; - optionally at least one alloying element chosen from: Cu and Ag, according to a mass fraction of 0.05 to 1.40%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Cu; according to a mass fraction of 0.05 to 3.00%, preferably 0.10 to 2.00%, preferably 0.10 to 1.60%, preferably 0.10 to 1.50%, preferably 0.10 to 1.40%, preferably 0.10 to 1.30%, preferably 0.10 to 1.20%, preferably 0.10 to 1.10%, preferably 0.10 to 1.00%, preferably 0.10 to 0.90%, preferably 0.10 to 0.80%, preferably 0.10 to 0.70% for Ag and in total; - optionally at least one alloying element chosen from: Zn and Li, according to a mass fraction of less than 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30% each and in total; - optionally at least one alloying element chosen from: Co, La, Ce, mischmetal, W, Ta, Nb, Nd, Y, Tm, Lu, Yb, Sr, Ba, Sb, Bi, Ca, P, B, In and Sn, according to a mass fraction less than or equal to 2.00%, preferably less than or equal to 1.50%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, more preferably less than or equal to 0.30%, even more preferably less than or equal to 0.10% each, and less than or equal to 2.00%, preferably less than or equal to 1.00%, preferably less than or equal to 0.50%, preferably less than or equal to 0.30% in total; - impurities: < 0.05% individually, and preferably < 0.15% in total; remainder aluminum.

13. Use of a powder according to claim 12, in an additive manufacturing process chosen from: laser powder bed fusion, electron beam melting, cold spraying, laser fusion deposition, friction additive manufacturing, plasma spark sintering and rotary friction welding, preferably laser powder bed fusion.

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