Alloy grade with improved strength

Abstract

The invention relates to a composition of a nickel superalloy consisting of: - an aluminum content by mass of between 0% and 0.5%, - a cobalt content by mass of between 0% and 12%, - a chromium content by mass of between 14% and 20%, - an iron content by mass of between 0% and 10%, - a molybdenum content by mass of between 0% and 2%, - a niobium content by mass of between 0% and 1%, - a tantalum content by mass of between 13% and 17%, - a titanium content by mass of between 0% and 1%, - a tungsten content by mass of between 0% and 3%, - a carbon content by mass of between 0% and 0.05%, - a manganese content by mass of between 0% and 0.5%, - a silicon content by mass of between 0% and 0.5%, as well as unavoidable impurities and the balance being nickel.

Description

Description Title of the invention: Grade of alloy with improved strength. Technical field

[0001] The invention falls within the technical field of metallurgy and more specifically that of alloy composition, more precisely alloys for an aeronautical application. Previous technique

[0002] Reducing polluting emissions is a major strategic challenge for the aeronautical industry.

[0003] In the field of propulsion, reducing these emissions involves increasing the efficiency of gas turbines, which themselves benefit from an increase in their operating temperature.

[0004] However, this temperature is limited by the heat resistance of the materials that make up the engine, particularly the low- and high-pressure turbine discs. In addition to the turbine discs, the turbine housings and the fastening systems for the components (screws, bolts, nuts) are also subjected to high temperatures and / or high stresses.

[0005] The difficulty in developing alloys for discs lies in achieving a compromise between high tensile strength at the disc bore, which is subjected to the highest mechanical stresses, and high creep resistance in the disc rim, which is subjected to the highest temperatures of around 750 °C.

[0006] Nickel-based superalloys have a microstructure consisting of a nickel-rich y matrix and generally adjoined with one or more phases contributing to mechanical reinforcement such as the y'-NisAl phase and the y"-Ni3Nb phase.

[0007] Nickel-based superalloys reinforced by the y-phase" (known as yy alloys), such as Inconel 718 or René 220 alloys, exhibit good mechanical properties at room temperature and up to about 650 °C.

[0008] Beyond this temperature, their mechanical properties degrade due to the evolution of the precipitates y" (metastables) into less hardening precipitates 5 (stables).

[0009] Superalloys strengthened by precipitation of the y' phase (known as y-y' alloys) generally exhibit superior strengths above 650 °C, making their use at higher temperatures possible. However, their low-temperature mechanical strength is lower than that of YY'- alloys.

[0010] However, these alloys are characterized by a lower formability caused by a faster precipitation kinetics of the Y' phase than of the y phase: the Y' phase precipitates rapidly upon cooling, the efforts required to deform the material are greater, as is the risk of generating surface cracks.

[0011] The weldability of yy' alloys is also less than that of yy' alloys, since the rapid precipitation of the Y' phase upon cooling generates stresses that can lead to cracking.

[0012] Superalloys yy' possessing comparable strength at temperatures below 650 °C to those of alloys yy" have been developed, or are under development. These include, for example, the alloys described in patent applications FR3133623 (Al) and FR3104613 (Bl).

[0013] However, these alloys contain a significant proportion of Y' phase which leaves only powder metallurgy and isothermal forging as implementation possibilities, generating a higher production cost.

[0014] We also know of JP2021134419 which describes temperature-resistant nickel-based alloys.

[0015] This is why there remains a need for new alloy compositions that would have the advantages of yy' alloys in terms of temperature resistance but that could be prepared by less expensive techniques. Description of the invention

[0016] The invention is specifically designed to address this need.

[0017] To achieve this, it proposes a composition of a nickel superalloy consisting of: - an aluminum mass content between 0% and 0.5%, - a cobalt mass content between 0% and 12%, - a chromium mass content between 14% and 20%, - an iron content by mass between 0% and 10%, - a molybdenum mass content between 0% and 2.0%, - a niobium mass content between 0% and 1.0%, - a tantalum mass content between 13% and 17%, - a titanium mass content between 0% and 1.0%, - a tungsten mass content between 0% and 3.0%, - a carbon mass content between 0% and 0.05%, - a manganese mass content between 0% and 0.5%, - a silicon mass content between 0% and 0.5%, as well as inevitable impurities and a supplement of nickel.

[0018] In this application, the expression "unavoidable impurities" is understood in the sense that it generally takes in the field of metallurgy, namely species which are not desired but whose presence is inherent in the history of the part, for example in the purification or preparation processes of one or more elements of the composition, or in the shaping processes of a part having the proposed composition.

[0019] In one embodiment, unavoidable impurities do not exceed 1000 ppm, or even 500 ppm, or even less than 100 ppm in the composition.

[0020] It is to the credit of the inventors that they determined that a composition according to the invention allowed an excellent optimum between the properties of the superalloys yy' and the superalloys yy" described in the literature.

[0021] More specifically, the composition allows the production of a nickel superalloy strengthened by precipitation of a tantalum-enriched y" phase stable at temperatures above 750 °C.

[0022] Such a composition allows in particular a heat treatment process of partial or total reconstitution of phase 5, making it possible to increase the size of the grains when desired, but also to maximize the precipitation potential of the hardening phase y" at lower temperatures for example between 700°C and 800°C by recovering the chemical elements constituting phase 5.

[0023] The inventors have succeeded in determining that the compositions of the invention, and even more so the restricted ranges that have just been described, offer an optimum composition among all the qualities sought for the alloy by guaranteeing a composition that possesses the following properties at temperatures between 700 °C and 800 °C: - a stable y"-Ni3Ta or ô-NisTa phase, in proportions compatible with significant reinforcement; - good microstructural stability guaranteeing the almost exclusive existence of only the yy" or y-5 phases; - a contained density; - satisfactory resistance to corrosion and oxidation.

[0024] In one embodiment, the composition comprises a cobalt mass content less than or equal to 6.0%.

[0025] The inventors determined that cobalt is a refractory element that improves the temperature stability of nickel alloys, meaning it maintains a microstructure that changes little over time, both in terms of the nature and relative fraction of the phases. It contributes to improving the alloy's creep resistance by reducing the stacking fault energy within the matrix.

[0026] Cobalt also contributes to the hardening of the matrix by solid solution. In addition, cobalt stabilizes the δ-NisTa phase and increases its dissolution temperature (solvus temperature), the delta phase being crystallographically close to the γ-NisNb phase, on which the mechanical properties of the γy superalloys are based.

[0027] However, cobalt is an element whose availability is not guaranteed and it is preferable to be able to do without it as much as possible in case of disruption to supply channels.

[0028] The proposed ranges therefore represent optimums between the different effects, even more optimized in the case of narrower ranges.

[0029] According to one example, the composition is free of cobalt, or has a cobalt mass content between 2.0% and 6.0%, for example between 2.0% and 5.0%.

[0030] In one embodiment, the composition comprises a chromium mass content of between 14% and 18%, or even between 14% and 16% or between 15% and 18%.

[0031] The inventors determined that the main effect of chromium additions is to increase the corrosion and oxidation resistance of superalloys. The presence of chromium leads to the formation of protective oxides (primarily Cr₂O₃ oxide, commonly called "chromium oxide") on the surface of the alloys, at the expense of less protective oxides such as nickel oxide (NiO). Chromium is also highly soluble in the matrix and contributes to its strengthening by solid solution.

[0032] Combined with carbon, chromium can form M-type carbides 23 C6 enhancing the mechanical properties of the alloy at high temperature, particularly creep resistance.

[0033] However, when introduced in excess, chromium promotes the formation of TCP phases such as o or p phases, which are detrimental from the point of view of mechanical properties.

[0034] The proposed ranges therefore represent optimums between the different effects.

[0035] In one embodiment, the composition comprises a mass content of iron between 0% and 6.0%, or even between 0% and 5.0%, or even between 1.0% and 5.0%.

[0036] The inventors determined that iron mainly substitutes for nickel in the y matrix.

[0037] Iron additions are beneficial for the alloy's recyclability, as its presence allows the use of partially ferrous filler metals during its production. Iron additions also reduce the alloy's density, as its density is lower than that of nickel (7.9 vs. 8.9 g / cm³). -3 ).

[0038] However, iron participates in the formation of TCP phases (including the Laves phase and the o phase).

[0039] The proposed ranges therefore represent optimums between the different effects, even more optimized in the case of narrower ranges.

[0040] In one example, the mass content of iron is between 5.0% and 10.0%.

[0041] In one embodiment, the composition comprises a molybdenum mass content of between 1.0% and 2.0%.

[0042] The inventors determined that molybdenum plays a significant hardening role in the y matrix due to its difference in atomic radius compared to nickel. It also has a low diffusion coefficient in the y matrix. Therefore, its hardening effect, and consequently the increase in static properties and creep resistance, persists over the long term at high temperatures.

[0043] In one embodiment, the composition comprises a niobium mass content of less than or equal to 0.5%, or even less than or equal to 0.2%.

[0044] The inventors determined that niobium contributes to the solid solution strengthening of the Y matrix as well as to the formation of the y"-Ni3Nb phase and also ô-NisNb.

[0045] Excessive additions of niobium promote the formation of the undesirable q-NisTi phase, particularly since it impairs the mechanical strength of the alloy when present in excessive quantities.

[0046] The proposed ranges therefore represent optimums between the different effects, even more optimized in the case of narrower ranges.

[0047] According to one example, the composition is devoid of niobium, or has a niobium mass content between 0.5% and 1.0%.

[0048] In one embodiment, the composition comprises a tantalum mass content of between 15% and 17%.

[0049] Tantalum is a refractory element which contributes to the solid solution strengthening of the y'-NisAl and Y"-Ni3Nb phases, as well as to the precipitation of MC carbides.

[0050] The inventors determined that the addition of this element in significant proportions promotes the formation of the γ-NisTa phase and therefore of the γ"-Ni3Ta phase.

[0051] Reinforcement by precipitation of the y"-Ni3Ta phase is beneficial for oxidation resistance compared to reinforcement obtained by precipitation of the y'-NisfAl,Ti phase), which oxidizes at high temperature due to the presence of titanium.

[0052] The proposed ranges therefore represent optimums between the different effects, even more optimized in the case of narrower ranges.

[0053] In one embodiment, the composition comprises a titanium mass content less than or equal to 0.5% or even less than or equal to 0.2%.

[0054] The inventors determined that the addition of titanium promotes the formation of the q-NisTi phase, decreasing the mechanical strength of the alloy when present in excessive amounts. Titanium also forms MC carbides and influences the precipitation kinetics of the β-NisTa phase, in which it substitutes for tantalum.

[0055] Excessive additions of titanium degrade the environmental resistance of the alloy, notably through the oxidation mechanism.

[0056] The proposed ranges therefore represent optimums between the different effects, even more optimized in the case of narrower ranges.

[0057] According to one example, the composition is free of titanium, or has a titanium mass content between 0.5% and 1.0%.

[0058] In one embodiment, the composition comprises a tungsten mass content greater than or equal to 0.5%, or greater than or equal to 1.0%, in particular between 0.5% and 3.0%, or even between 1.0% and 3.0%.

[0059] Tungsten is a refractory element with a low diffusion coefficient in the y matrix, increasing its stability in addition to strengthening it by solid solution.

[0060] However, when introduced in excess, tungsten promotes the formation of TCP phases such as the p phase, which is detrimental from the point of view of mechanical properties.

[0061] According to one example, the composition is free of tungsten.

[0062] In one embodiment, the composition comprises a mass content of carbon between 0.01% and 0.03%.

[0063] The inventors determined that the addition of carbon in superalloys leads to the formation of carbides, for example of MC or M23C6 stoichiometry, where M denotes one or more carbide-forming elements.

[0064] The formation of these carbides creates obstacles to the movement of dislocations within the material and thus improves its mechanical resistance, particularly at high temperatures.

[0065] In one embodiment, the composition comprises a mass content of manganese between 0.03% and 0.07%.

[0066] In one embodiment, the composition comprises a silicon mass content of between 0.03% and 0.07%.

[0067] The inventors determined that small additions of manganese and / or silicon improve the adhesion of the alloy's passivation layer that forms under environmental stress, thus increasing resistance to corrosion and oxidation.

[0068] In particular, it is to the inventors' credit that they have succeeded in identifying compositions that allow the following properties over temperature ranges exceeding 700°C: - a phase matrix y reinforced by solid solution; - a hardening phase rich in tantalum, possibly substituted by the elements Al, Nb and Ti; - a thermal treatment interval for resolving phase 5 of at least 50 °C; - a limitation of the TCP phase fraction.

[0069] The so-called "TCP" phases, for the English acronym "topologically closed-packed", are phases that form after long-term thermal aging, consuming alloying elements that would otherwise be used for strengthening by solid solution or precipitation, and which are detrimental to the structure in that they offer crack initiation sites, thus diminishing the mechanical properties of the alloy.

[0070] That is why the inventors determined that it was important to minimize or even eliminate the presence of TCP phases.

[0071] According to another aspect, the invention also relates to a method for obtaining an aeronautical part comprising at least the following steps: - a shaping step of a part into an alloy described above; - a precipitation income of the hardening phase y" by a heat treatment carried out at a temperature between 750 °C and 850 °C for a duration between 6 hours and 24 hours.

[0072] It is to the credit of the inventors that they determined that the composition made it possible to obtain, with an alloy described above and the proposed heat treatment, parts with improved mechanical properties.

[0073] In one embodiment, the shaping step can be a forging step, a casting step, a powder metallurgy step, or even an additive manufacturing step.

[0074] In one embodiment, the shaping step may be followed by a solution step at a temperature above the solvus of phase 5 but below the solidus of the alloy.

[0075] Such a step, carried out after shaping but before the precipitation tempering step, advantageously allows the grain size to increase when desired, but also to recover all the alloying elements contained in phase 5 so that they can be brought to the hardening phase y" in the continuation of the heat treatment.

[0076] In one embodiment, the shaping step may be followed by a solution step at a temperature above the solvus of phase 5 but below the solidus of the alloy.

[0077] Such a step, carried out after shaping but before the precipitation tempering step, advantageously allows recovery of some of the alloying elements contained in phase 5 so that they can be brought to the hardening phase y" in the continuation of the heat treatment, while maintaining the initial grain size.

[0078] According to another aspect, the invention relates to a part made of an alloy whose composition is as described above or a part obtained according to a process which has just been described.

[0079] Indeed, it is to the credit of the inventors that they were able to determine that the proposed compositions offered interesting features for such parts, particularly for the optimum properties described above.

[0080] In one embodiment, the aeronautical part is an aeronautical turbomachine part whose composition is that described above.

[0081] In particular, such a part may be an aeronautical turbomachine part exposed to stress and temperature exceeding 700°C or even exceeding 750°C.

[0082] For example, such parts can be an aircraft turbomachine disc, a turbine housing, an exhaust housing, a turbine shaft, a screw, a bolt.

[0083] It is indeed for such parts that it is particularly advantageous to use a composition of the invention. Description of the implementation methods

[0084] The invention is now described using examples which should not be considered as limiting the invention but which have been chosen by the inventors to allow an optimum for the following four properties over temperature ranges between 700 °C and 800 °C: - a Y-phase matrix reinforced by solid solution; - a hardening phase rich in tantalum, possibly substituted by the elements Al, Nb and Ti; - a thermal treatment interval for resolving phase 5 of at least 50 °C; - a limitation of the TCP phase fraction. Examples

[0085] Table 1 describes the composition of the examples according to the invention and of the comparative alloys, expressed as mass percentages. Alloy Ni Al C Co Cr Fe Mn Mo Nb Si Ta Ti W Ex 1 bal. 0.5 0.020 12 14 - 0.05 - 1.00 0.05 13.0 1 Ex 2 ball. 0.020 - 20 - 0.05 2 0.05 15.0 Ex 3 ball. 0.020 2 18 5.0 0.05 1 0.05 17.0 Ex 4 ball. 0.020 4 18 5.0 0.05 1 0.05 15.0 Ex 5 ball. 0.020 5 18 5.0 0.05 1 0.05 15.0 Ex 6 ball. 0.020 - 15 10.0 0.05 2 0.05 15.0 3.0 CEx 1 bal. 0.5 0.040 - 19 18.5 0.18 3 5.00 0.18 - 0.90 - CEx 2 bal. 1.0 0.030 7 21 - - 3 4.00 - 2.1 0.50 3.1 CEx 3 bal. 0.5 0.015 12 18 - - 3 5.00 - 3.0 1.00 - CEx 4 bal. 0.5 0.044 - 19 18.0 - 3 0.02 0.02 9.1 1.04 -

[0086] Table 2 describes the calculated properties for the examples (Ex) and comparative alloys (CEx), outside the scope of this invention, whose compositions are given in Table 1. (Number) to Solvus γ'-Ni₃Al at TCP at ô-NisTa at Carbures at Solvus Alloy (g.cirr 700 °C (Ta)5 to 700 °C carbide 700 °C 700 °C 700 °C δ-Ni₃Ta (°C) Solvus carbides (°C) Δ1 (°C) Δ2 (°C) (%mol.) (%mol.) ³) (%mol.) (%mol.) (%mol.) (% at.) (°C) (°C) Ex 1 9.00 16 7 17 1 0.2 1078 1286 224 16 Ex 2 9.12 25 25 5 0.5 1106 1042 205 269 Ex 3 9.20 22 25 - 0.5 1229 1046 58 241 Ex 4 9.09 19 25 - 0.5 1167 1014 135 288 Ex 5 9.09 19 25 - 0.5 1173 1012 125 287 Ex 6 9.30 18 24 5 0.5 1213 1049 85 250 CEx 1 8.19 14 19 - 11 0.4 1039 1291 211 -40 CEx 2 8.50 11 20 1 10 5 0.7 1029 1303 265 -8 CEx 3 8.49 22 18 1 - 2 0.3 1109 1280 166 -6 CEx 4 8.55 21 1 23 - 11 1.1 1140 1265 116 -8

[0087] Table 2 lists the following properties for each composition, in column order: - the density p determined via the modified Hull law, for example described in the following article: FC Hull, Metal Progress, Nov. 1969, pp 139-140; - the mole fraction of the β-NisTa phase at 700 °C, representing the mole fraction of the Y" phase at 700 °C; - the molar content of niobium in phase 5 at 700 °C, representing the molar content of niobium in phase Y" at 700 °C; - the molar content of tantalum in phase 5 at 700 °C, representing the molar content of tantalum in phase Y" at 700 °C; - the mole fraction in phase Y'-NÎSAI at 700 °C; - the total mole fraction in TCP phases at 700 °C; - the mole fraction of carbide at 700 °C; - the solvus temperature of the ô-NisTa phase; - the solvus temperature of the MC or M carbides 23 C6; - the heat treatment window for resolving the δ phase, designated Δ1; - the heat treatment window for resolving the carbides, designated Δ2.

[0088] The molar contents or mole fractions as well as the solvus temperatures are determined by the CALPHAD method, i.e. via calculations of phase diagrams at thermodynamic equilibrium simulated over the interval 650 °C-1400 °C by exploitation of the TCNI10 thermodynamic database proposed by the company Thermo-Cale Software AB, Sweden.

[0089] The determined data is supplemented by the following considerations: - The TCP phases are all equally detrimental to mechanical properties, and the o, p, P phases as well as the Nb5Ni phase 75 Ti 20 are considered to be TCP phases; - The carbide solvus temperature reported in [Table 2] is the highest solvus temperature among M-type carbides 23 C6ou MC; - The heat treatment window for resolution of the δ phase, denoted Δ1, corresponds to the difference between the solidus and solvus temperatures of the δ-Ni3Ta phase; - The heat treatment window for resolution of the carbides, denoted Δ2, corresponds to the highest difference between the solidus and solvus temperatures among the M-type carbides 23 C6ou MC; - the δ phase is the only one that is predicted to be stable at thermodynamic equilibrium; however, its existence experimentally implies the prior existence of a tantalum-rich y" phase, for which the advantages detailed previously are expected; - for example 1 and comparative examples 3 and 4, the fraction of phase given for the δ-Ni3Ta phase also includes the η-Ni3Ta phase, which is slightly richer in tantalum than phase 5.

[0090] The analysis of examples and comparative examples allows us to establish the following behaviors.

[0091] The density of the alloys of the invention is greater than that of the comparative alloys.

[0092] However, none of the comparative alloys present the compromises offered by the alloys of the invention: presence of a tantalum-rich phase 5 at high solvus temperature and which can be re-solved, limited TCP phase content, controllable carbides and superior environmental resistance.

[0093] The bulk density of these alloys is certainly higher than that of the comparative examples, but the improvement of mechanical properties at both high and low temperatures makes it possible to reduce certain thicknesses of parts at iso-performance and therefore to reduce the mass of the final parts.

[0094] The presence of a tantalum-rich phase 5, rather than a niobium-rich phase 5; at a minimum, the example alloys have a phase 5 containing at least 17 at.% tantalum. Comparative alloys CEx 1 to CEx 3 have a niobium-rich δ-Ni₃Ta phase. Comparative alloy CEx 4 has a tantalum-rich δ-Ni₃Ta phase in proportions comparable to, or even greater than, those of the example alloys, but it also has the highest content of deleterious TCP phases.

[0095] The alloys according to the invention have a high solvus temperature of the δ-Ni3Ta phase and in particular higher than the maximum intended use temperature (800 °C).

[0096] The high solvus temperatures explain the existence of a δ-Ni3Ta phase fraction greater than that of the comparative alloys CEx 1 and CEx 2 at 700 °C.

[0097] The alloys of the invention all allow the existence of a heat treatment window for resolution of phase 5 (Al > 58 °C) which is realistic from an industrial point of view.

[0098] The alloys of the invention allow for the presence of a low fraction of TCP phases at 700 °C, at most 5 mol%. The example alloys have an amount of TCP phases at most equal to that of alloy CEx 2, the alloy with the least amount in all the comparative examples.

[0099] The alloys examples of the invention are therefore less sensitive to embrittlement by the precipitation of TCP phases than the comparative alloys CEx 1, CEx 3 and CEx 4.

[0100] The alloys exemplifying the invention allow a low presence of carbides, at most 0.4 mol%, and whose resolution is possible thanks to the existence of a thermal treatment window for resolution of the carbides (A2 > 0), unlike the comparative alloys, for which Δ2 is negative.

[0101] This ensures industrially that it is possible to finely control the presence of these carbides.

[0102] Table 3 presents the activity of nickel and chromium calculated at 700 °C for the exemplified alloy compositions.

[0103] [Table 3] Nickel activity at Chromium activity at Alloy 700 °C (×10 3 ) 700 °C (×10 3 ) Ex 1 2.0 5.8 Ex 2 2.0 10.6 Ex 3 1.7 10.8 Ex 4 1.8 9.5 Ex 5 1.7 9.4 Ex 6 1.7 8.6 CEx 1 1.3 10.4 CEx 2 1.7 10.4 CEx 3 1.8 7.7 CEx 4 1.3 10.4

[0104] The activity of the chromium in the alloys of the invention is greater than that of nickel at 700 °C, suggesting a preferential formation of chromium oxide Cr2O3, considered protective, rather than nickel oxide NiO, considered not very protective.

[0105] With the exception of alloy Ex 1, the values ​​obtained for the alloys of the invention are close to those of alloy CEx 1.

[0106] In practice, the CEx 1 alloy is known for its high-temperature environmental resistance, which tends to indicate that the alloys of the invention will perform adequately.

[0107] Furthermore, although the example alloy Ex 1 may not be as strong as the other alloys of the invention, it has a sufficient chromium content to ensure the formation of a protective chromium Cr2O3 layer.

[0108] Other calculation results were obtained between the composition of example 2 of document JP 2021 134419 (outside the invention), noted "JP_Ex2" in the table below, and five alloys "JP_Ex2_Mol" to "JP_Ex2_Mo5" which constitute alloys according to the invention having different molybdenum contents.

[0109] [Table 4] TCP at 700 °C δ-Ni3Ta at 700 °C (Ta) δ at 700 °C Cr Mo Ni Ta alloy ρ (g.cm -3 ) ( %mol) (%mol.) JP_Ex2 17.8 4.5 14 9.15 8.1 14 24 JP_Ex2_Mol 17.8 - 14 9.07 11 25 JP_Ex2_Mo2 17.8 0.5 14 9.08 11 25 ball. JP_Ex2_Mo3 17.8 1' 14 9.09 12 25 JP_Ex2_Mo4 17.8 1.5 14 9.1 13 25 JP_Ex2_Mo5 17.8 2 14 9.1 0.1 13 24

[0110] These calculation results show that the "JP_Ex2" alloy exhibits a significantly higher TCP phase precipitation than the alloys according to the invention. An increase in density can also be observed in this non-invention alloy compared to the alloys according to the invention.

[0111] The two other properties evaluated, namely the mole fraction of the δ-Ni3Ta phase and the tantalum molar content in phase 5 at 700 °C, are not particularly different from those of the comparative alloy.

Claims

Demands

1. Composition of a nickel superalloy consisting of: - an aluminum mass content between 0% and 0.5%, - a cobalt mass content between 0% and 12%, - a chromium mass content between 14% and 20%, - an iron content by mass between 0% and 10%, - a molybdenum mass content between 0% and 2.0%, - a niobium mass content between 0% and 1.0%, - a tantalum mass content between 13% and 17%, - a titanium mass content between 0% and 1.0%, - a tungsten mass content between 0% and 3.0%, - a carbon mass content between 0% and 0.05%, - a manganese mass content between 0% and 0.5%, - a silicon mass content between 0% and 0.5%, as well as inevitable impurities and a supplement of nickel.

2. Composition according to claim 1, wherein the mass content of cobalt is less than or equal to 6.0%.

3. Composition according to any one of claims 1 or 2, wherein the mass content of chromium is between 14% and 18%.

4. Composition according to any one of claims 1 to 3, wherein the iron mass content is between 0% and 6.0%.

5. Composition according to any one of claims 1 to 4, wherein the molybdenum mass content is between 1.0% and 2.0%.

6. Composition according to any one of claims 1 to 5, wherein the niobium mass content is less than or equal to 0.5%.

7. Composition according to claim 6, wherein the composition is devoid of niobium.

8. Composition according to any one of claims 1 to 7, wherein the tantalum mass content is between 15% and 17%.

9. Composition according to any one of claims 1 to 8, wherein the mass content of titanium is less than or equal to 0.5%.

10. Composition according to claim 9, wherein the composition is devoid of titanium.

11. Composition according to any one of claims 1 to 10, wherein the mass content of tungsten is greater than or equal to 0.5%.

12. Composition according to any one of claims 1 to 10, wherein the composition is devoid of tungsten.

13. Composition according to any one of claims 1 to 12, wherein the mass content of carbon is between 0.01% and 0.03%.

14. Composition according to any one of claims 1 to 13, wherein the mass content of manganese is between 0.03% and 0.07%.

15. Composition according to any one of claims 1 to 14, wherein the mass content of silicon is between 0.03% and 0.07%.

16. A method for obtaining an aeronautical part comprising at least the following steps: - a step of shaping a part into an alloy according to any one of claims 1 to 15; - a precipitation income of the hardening phase y" by a heat treatment carried out at a temperature between 750 °C and 850 °C for a duration between 6 hours and 24 hours.

17. A method for obtaining the product according to claim 16, wherein the shaping step is selected from a forging step, a casting step, a powder metallurgy step, or an additive manufacturing step.

18. A method of obtaining according to claim 16 or 17, further comprising a step of dissolving at a temperature above the solvus of phase 5 but below the solidus of the alloy.

19. An aeronautical turbomachine component whose composition is according to any one of claims 1 to 15 or obtained according to a process of any one of claims 16

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