Nickel-based alloy powder comprising Y2O3 oxide

Abstract

The present invention provides a nickel-based alloy powder composed of 0.2 to 5% Y2O3 oxide, the remainder of the powder having the following composition: 0.050 to 0.090% C; 14.25 to 15.75% Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% Mo; 3.00 to 3.70% Ti; 0.012 to 0.020% B; 0 to 0.50% Fe; 0 to 0.060% Zr; 0 to 0.150% Mn; 0 to 0.20% Si; 0 to 0.10% Cu; 0 to 25 ppm S; 0 to 0.5 ppm Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 60 ppm of N2; and 0 to 200 ppm of O; Ni making up the balance of the composition; given that the percentages and ppm mentioned above are relative to the total of the remaining powder. An alloy that can be produced from this powder and a process for producing this alloy from this powder are also proposed. Abstract figure: Figure 2

Description

Title of the invention: Nickel-based alloy powder comprising Y2O oxide 3 technical field

[0001] This disclosure relates to the field of nickel-based alloys for aeronautical parts, as well as the field of alloy powders and processes for producing such alloys by laser powder bed fusion. Previous technique

[0002] Several materials are commercially available today for the production of alloys by laser beam melting (also known as LBM), for example Inconel 718. However, this material does not withstand temperatures exceeding 650°C. Yet, the operating environment temperature of a turbine or chamber is much higher.

[0003] Another available material is Hastelloy X which can reach up to 950°C, but which is very limited mechanically and can only be used for the manufacture of lightly loaded parts.

[0004] Similarly, the material CoCr (cobalt-based alloy) has been commercially developed. This alloy is used particularly for injection systems and can withstand temperatures of approximately 1000°C. However, it also exhibits limited mechanical properties and is not suitable for the requirements of turbine components (blades and distributors).

[0005] For some years now, materials meeting the mechanical, thermal, oxidation, and corrosion requirements of these parts have been commercially available, and others are under development. FIN738 is one example. However, it exhibits macrocracking problems that make its use in the intended applications impossible. FIN939 and FABD900 are also worth mentioning. These last two materials have only recently entered the market (less than two years) and their properties still need to be demonstrated and further developed. Finally, NK15CADT LBM has been available for longer but suffers from microcracking, which makes its manufacturability difficult. Furthermore, it remains limited to a maximum temperature of 1050°C.

[0006] Therefore, there is currently no alloy solution that allows temperatures above 1050°C to be reached while exhibiting good finishing properties and good manufacturability.

[0007] NASA is developing alloys similar to the proposal made, but based on different materials: https: / / ntrs.nasa.gov / citations / 20200000360. In particular, two compositions as follows: Composition 1: 32% cobalt; 30% chromium; 1.5% rhenium; 0.003% boron; nickel making up the balance; Composition 2: 33% cobalt; 29% chromium; 1.5% rhenium; and undisclosed percentages of aluminum, titanium, niobium, molybdenum, tungsten, zirconium, carbon and boron; nickel making up the balance.

[0008] Furthermore, university studies are also examining these possibilities, such as the one on IN625 ODS LBM: https: / / doi.org / 10.1016 / j.msea.2022.143813. This alloy is based on Inconel 625 to which up to 1.0% by weight of Y2O3 particles have been added. Inconel 625 has the following composition: at least 58.0% nickel; 20.0 to 23.0% chromium; up to 5.0% iron; 8.0 to 10.0% molybdenum; 3.15 to 4.15% niobium (plus tantalum); up to 0.10% carbon; up to 0.50% manganese; up to 0.50% silica; up to 0.015% phosphorus; up to 0.015% sulfide; up to 0.40% aluminium; up to 0.40% titanium and up to 1.0% cobalt. Brief description of the invention

[0009] This disclosure improves the situation.

[0010] A nickel-based alloy powder is proposed, composed of 0.2 to 5% of Y2O3 oxide, the remainder of the powder having the following composition: 0.050 to 0.090% C; 14.25 to 15.75% Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% Mo; 3.00 to 3.70% Ti; 0.012 to 0.020% B; 0 to 0.50% Fe; 0 to 0.060% Zr; 0 to 0.150% Mn; 0 to 0.20% Si; 0 to 0.10% Cu; 0 to 25 ppm S; 0 to 0.5 ppm Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 60 ppm of N2; and 0 to 200 ppm of O; Ni making up the balance of the composition; given that the percentages and ppm mentioned above are given relative to the total of the rest of the powder.

[0011] Other optional and non-limiting features are described below.

[0012] The alloy powder may be composed of two particle populations: Y2O3 oxide particles and metallic particles constituting the remainder of the powder. The Y2O3 oxide particles may have dimensions ranging from 50 to 500 nm.

[0013] The alloy powder particles may have a metallic core made up of the composition and a surface layer made up of Y2O3 oxide around the metallic core.

[0014] The alloy powder can have the following particle size profile: D10 from 10 to 25 pm; D50 from 25 to 40 pm; and D90 from 40 to 70 pm.

[0015] The alloy powder particles may have a substantially spherical shape.

[0016] A nickel-based alloy is also proposed comprising: 0.050 to 0.090% C; 14.25 to 15.75% Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% Mo; 3.00 to 3.70% Ti; 0.012 to 0.020% B; 0 to 0.50% Fe; 0 to 0.060% Zr; 0 to 0.150% Mn; 0 to 0.20% Si; 0 to 0.10% Cu; 50 to 1000 ppm Y; 0 to 25 ppm S; 0 to 0.5 ppm Bi; 0 to 5 ppm Ag; 0 to 5 ppm of Pb; 0 to 100 ppm of N2; 0 to 1000 ppm of O; 0 to 500 ppm of Pt; and 0 to 500 ppm of V; Ni making up the balance of the rest of the composition; given that the percentages and ppm mentioned above are given in relation to the weight of the total composition; the quantity of each of the other elements, called traces, being limited to 50 ppm with a total limited to 500 ppm.

[0017] A process for producing the alloy described above from the powder described above is also proposed. The process comprises: producing the powder by atomization; melting the powder by laser powder bed fusion.

[0018] Other optional and non-limiting features of the process are presented below.

[0019] The process may further include, after melting, hot isostatic compaction.

[0020] The process may further include at least one of the following treatments producing the following employment state: grain growth; resuspension and reprecipitation; and income.

[0021] In which case, the process may further include a detensioning before the first of the treatments producing the state of use or after the last of the treatments producing the state of use. Brief description of the drawings

[0022] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0023] [Fig. 1] schematically illustrates an embodiment of the Ni-based alloy powder of the present invention; in this embodiment, the alloy powder comprises two populations of particles: metallic particles and oxide particles. Fig. 2

[0024] [Fig.2] schematically illustrates another embodiment of the alloy powder with In this other embodiment of the present invention, the alloy powder is composed of particles having a structure comprising a metallic core and a surface layer of oxide. Fig. 3

[0025] [Fig.3] schematically illustrates the steps of a process for producing an alloy with Based on the alloy powder of the invention, this process includes an atomization step and a melting step. Fig. 4

[0026] [Fig.4] schematically illustrates the meander strategy of laser fusion on a bed of powder usable for the melting step of the process for developing the invention. Fig. 5

[0027] [Fig.5] schematically illustrates the band strategy of laser bed fusion powder usable for the melting step of the process for developing the invention. Fig. 6

[0028] [Fig.6] schematically illustrates the contour strategy of laser bed fusion powder usable for the melting step of the process for developing the invention. Fig. 7

[0029] [Fig.7] schematically illustrates the island strategy of laser fusion on a bed of Powder usable for the melting step of the process for developing the invention. Fig. 8

[0030] [Fig.8] schematically illustrates the other optional steps of the process for the development of a Ni-based alloy from the alloy powder of the invention, enabling the performance of the alloy to be improved according to the desired application. Description of embodiments

[0031] The present invention proposes a nickel-based alloy powder enabling the easy production by laser powder bed fusion of an alloy having good tensile strength, fatigue, fineness and resistance to oxidation and corrosion up to at least 1100°C.

[0032] This alloy powder is composed of 0.2 to 5% of Y2O3 oxide, the remainder of the powder having the following composition: 0.050 to 0.090% of C; 14.25 to 15.75% of Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% of MB; 3.00 to 3.70% Ti; 0.012 to 0.020% of B; 0 to 0.50% of Fe; 0 to 0.060% of Zr; 0 to 0.150% of Mn; 0 to 0.20% of Si; 0 to 0.10% Cu; 0 to 25 ppm of S; 0 to 0.5 ppm of Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 60 ppm of N2; and 0 to 200 ppm of O; Nor by balancing the composition; given that the percentages and ppm mentioned above are given in relation to the total of the rest of the powder.

[0033] The Y2O3 oxide may be present in the powder in the form of nanometric PO particles (see [Fig. 1]). In this case, the remainder of the powder consists of PM metallic particles. Thus, the alloy powder comprises two populations of mixed particles: PM metallic particles and PO oxide particles. This mixture can be obtained by simple mechanical mixing, particularly according to batch-mixing procedures.

[0034] Preferably, the PO oxide particles have dimensions ranging from 50 to 500 nm. This characterization can be measured, in particular, by dynamic light scattering (DLS); the size corresponding to the peak of the particle size distribution is retained. Instruments enabling such measurements include the Zetasizer Pro, the Zetasizer Ultra, and the Zetasizer Lab from Malvem Panalytical.

[0035] Preferably, the assembly consisting of PM metallic particles has the following particle size profile: D10 of 10 to 25 pm; D50 from 25 to 40 pm; and D90 from 40 to 70 pm.

[0036] This particle size profile ensures the good processability of the alloy powder by laser powder bed fusion. Indeed, it allows for good compaction of the powder bed, good flowability, but also a reduction in melting stresses, which limits microcracking of the alloy.

[0037] PM metallic particles can be obtained by atomization, which ensures good morphology of the powder produced, particularly to ensure sphericity of the powder particles. Atomization also helps to limit the risk of pollution.

[0038] Atomization can be carried out, for example, on René 77 powder whose chemical composition is as follows: 0.05 to 0.09% of C; 14.25 to 15.75% of Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% of MB; 3.00 to 3.70% Ti; 0.012 to 0.020% of B; 0 to 0.5% of Fe; 0 to 0.06% of Zr; 0 to 0.15% of Mn; 0 to 0.20% of Si; 0 to 0.10% Cu; 0 to 25 ppm of S; 0 to 0.5 ppm of Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 100 ppm of N2; 0 to 300 ppm of O; 0 to 500 ppm of Pt; and 0 to 500 ppm of V; the quantity of each of the other elements, called traces, being limited to 50 ppm with a total limited to 500 ppm.

[0039] Compared to René 77 powder, that of the present invention has a reduced S content of 25 ppm to ensure better resistance to oxidation and corrosion as well as a reduction in the risk of microcracking, while ensuring technical feasibility for atomization.

[0040] Sieving can be carried out after atomization in order to ensure that the particle size profile mentioned above is obtained.

[0041] The choice of the starting powder, the atomization and the sieving which the latter is provided guarantees a good maintenance of the desired particle size and chemical composition, that is to say it allows to control well and in a reproducible manner the size of the grains of powder obtained (particle size) and the chemical composition of the powder.

[0042] Alternatively, the particles of this powder typically have a metallic core CM consisting of the composition and a surface layer CS consisting of Y2O3 oxide around the metallic core CM (see [Fig. 2]). This ultimately results in a more uniform oxide distribution in the final material.

[0043] Preferably, the CS surface layer of oxide has a thickness of 50 to 500 nm, and always preferably a thickness of one grain of powder on the surface.

[0044] This powder particle structure can be obtained by mixing two populations of PM and PO particles, as described in the preceding paragraphs, particularly by using a high-frequency oscillating mixer and applying stress. This process leads to the crushing of the PO oxide particles, which then form the surface oxide layers CS, on the surface of the PM metallic particles, which form the CM metallic cores. The oscillatory frequency can be 50 Hz or higher. The stress can be 50 MPa or higher.

[0045] In general, the powder can have the following particle size profile: D10 from 10 to 25 pm; D50 from 25 to 40 pm; and D90 from 40 to 70 pm.

[0046] This particle size profile ensures the good processability of the alloy powder by laser powder bed fusion. Indeed, it allows for good compaction of the powder bed, good flowability, but also a reduction in melting stresses, which limits microcracking of the alloy.

[0047] The alloy powder particles may have a substantially spherical shape.

[0048] Thus, this alloy powder, after laser melting on a powder bed, makes it possible to obtain a nickel-based alloy having the desired properties.

[0049] This alloy has in particular the following chemical composition: 0.050 to 0.090% of C; 14.25 to 15.75% of Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% of MB; 3.00 to 3.70% Ti; 0.012 to 0.020% of B; 0 to 0.50% of Fe; 0 to 0.060% of Zr; 0 to 0.150% of Mn; 0 to 0.20% of Si; 0 to 0.10% Cu; 50 to 1000 ppm of Y; 0 to 25 ppm of S; 0 to 0.5 ppm of Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 100 ppm of N2; 0 to 1000 ppm of O; 0 to 500 ppm of Pt; 0 to 500 ppm of V; and Nor taking into account the balance of the rest of the composition; given that the percentages and ppm mentioned above are given in relation to the total weight of the composition; the quantity of each of the other elements, called traces, being limited to 50 ppm with a total limited to 500 ppm.

[0050] This alloy can in particular be obtained from a manufacturing process using the alloy powder described above ([Fig.3]).

[0051] This manufacturing process comprises: the SOI production of the powder by atomization; SO2 fusion of powder by laser powder bed fusion.

[0052] Laser powder bed fusion is an additive manufacturing technique used particularly for the production of metal parts. It consists of spreading a thin layer of metal powder onto a platform, then using a high-power laser to selectively melt the metal powder particles along a trajectory defined, for example, by a 3D digital model. The laser melts the metal powder along its trajectory over a line width, leaving behind a line or bead of solidified metal. After the layer has solidified in the desired areas, a new layer of powder is deposited, and the process is repeated layer by layer until the complete part is formed. In this process, the unsolidified metal powder is not removed in order to serve as a substrate for the next layer.This process makes it possible to produce complex parts with high precision and an excellent level of detail, while minimizing material waste.

[0053] SO2 fusion is carried out under a neutral atmosphere, preferably under an atmosphere of argon or nitrogen.

[0054] Laser SO2 powder bed fusion can be achieved by using a laser power of 150 W to 300 W.

[0055] The laser travel speed is from 900 mm / s to 1300 mm / s.

[0056] The thickness of the layers is preferably from 20 to 60 pm.

[0057] The line width is preferably from 50 to 200 pm. Alternatively, the overlap between fusion lines is from 20 to 150 pm. The overlap between fusion lines refers to the width of the gap between the areas to which laser power is applied between two adjacent lines. This overlap prevents insufficient fusion of the alloy in an interstitial area between two lines. because the laser power is not constant across the entire laser spot and varies slightly towards the periphery.

[0058] Several strategies exist for fusing the entire surface S required to manufacture the desired part onto a single layer: meander, band, contour, and island. In the meander strategy (see [Fig. 4]), the laser describes a back-and-forth path L (the direction of laser movement is represented by the arrows in the figures) across the entire width of the surface S of the powder bed P to be fused. In the band strategy (see [Fig. 5]), the surface S of the powder bed P to be fused is divided into bands B, and the laser describes a back-and-forth path L between the lateral boundaries of one band B before moving to another band B (in [Fig. 5], the back-and-forth path is shown in only one band for clarity). In the contour strategy (see [Fig. 6]), the laser first describes the contour of the surface S of the powder bed P to be fused, and then its path follows this contour while progressing towards the interior of this surface S to be fused.Finally, in the island strategy (see [Fig.7]), the surface S of the powder bed P to be fused is divided into small zones Z in each of which the laser describes a back-and-forth L (in [Fig.7], the back-and-forth path is only shown on four adjacent zones for readability reasons); the orientation of the back-and-forth L can change from one zone Z to another, for example undergoes a 90° rotation from one zone to another adjacent one.

[0059] Here, although all strategies are usable, the banding strategy is preferred. In this case, the band width can be from 2 to 15 mm. The overlap between bands can be from 0.05 to 0.15 mm. The overlap between bands refers to the width of the overlap between the areas to which the laser power is applied between two adjacent bands. The overlap prevents a lack of fusion of the alloy in an interstitial zone between two adjacent bands because the laser power is not constant across the entire laser spot and varies slightly towards the periphery.

[0060] The orientation of the B bands can be different from one layer to another, preferably it undergoes a rotation of 60 to 75°, preferably of 65 to 70°, for example 67° between two successive layers.

[0061] These fusion parameters ensure a sufficient energy input during fusion, while limiting residual stresses and microcracking.

[0062] During this SO2 melting, the oxide, which is very small, dissolves uniformly in the material matrix and serves as anchoring zones for the dendrites during solidification, thus preventing the formation of interdendritic microcracks. In some cases, a few oxide particles may nevertheless remain in the alloy matrix. However, these rare residual oxide particles are not such as to compromise the performance of the alloy.

[0063] The alloy composition given above is obtained after this SO2 melting process. The only elements modified compared to the initial metal particles are the O, Y, and N2 content, as well as the addition of trace elements. The modification of the O and N2 content is associated with i) the absorption of these elements during the melting of the powder grains, ii) the absorption of these elements in the manufacturing chamber on the unmelted powder, which is then reused for subsequent production runs (recycling), and iii) the addition of the Y2O3 oxide. The modification of the Y content results directly from the added oxide. Industrially, it is therefore necessary to plan for an increase in the concentration between the powder and the fused material. These concentrations are fixed with regard to the mechanical properties obtained and industrial capabilities.

[0064] Several treatments can then be carried out after melting to improve the properties of the alloy depending on the intended application (see [Fig. 8]). These treatments include: hot isostatic compaction S03; a growth of grains S05; a return to solution S06 and reprecipitation S06'; and an income S07.

[0065] Grain growth S0 5, resuspension S06 and reprecipitation S06', and income S07 are said to be treatments producing the employment state.

[0066] Only one of these treatments may be planned, or a combination of at least two of them. In the case of a combination, the treatments are carried out in this order, eliminating the unnecessary treatments.

[0067] Hot isostatic pressing S03 increases the density of the alloy. Hot isostatic pressing S03 involves applying high temperature and pressure, completing the melting process and filling gaps where melting was insufficient in the alloy.

[0068] Hot isostatic compaction S03 can be carried out at a temperature of 1190 to 1210 °C, preferably 1195 to 1205 °C, for example 1200 °C. The applied pressure is preferably greater than 100 MPa. The holding time at this temperature and pressure is at least 4 hours and may exceed this duration by 20%.

[0069] Grain growth S05 allows for the enlargement of the metallurgical grain size. Indeed, this is relatively small as it comes out of the melt, on the order of 2 to 7 ASTM. However, the finishing properties are better when the grain size is larger, as in foundry work with a grain size on the order of 00 ASTM (in the ASTM notation, the higher the number, the smaller the grain size). This treatment aims to achieve a grain size of 00 to 5 ASTM, which guarantees good finishing, tensile, and fatigue properties; therefore, it is suitable for turbine blades and distributors. It is particularly advantageous for the manufacture of parts intended for Some components are subject to fine-tuning constraints, such as distributors and turbine blades. In other cases, it is not necessary, for example, chamber parts, turbine sealing sectors or OSAS, retaining rings or casing parts that are not subject to fine-tuning constraints.

[0070] Grain growth S05 is typically achieved by high-temperature quenching, particularly after hot isostatic pressing S03. Quenching can be carried out at a temperature of 1220 to 1240 °C, preferably 1225 to 1235 °C, for example 1230 °C. The holding time at this temperature can be 5 hours and can exceed this value by 20%. At the end of this treatment, the alloy is simply exposed to air.

[0071] Resolution S06 dissolves secondary phase particles or precipitates included in the alloy matrix, resulting in improved compositional homogeneity. Resolution is followed by reprecipitation S06'.

[0072] Typically, the S06 resolution can be carried out by heating the alloy to a temperature of 1150 to 1170 °C, preferably from 1155 to 1165 °C, for example 1160 °C. The holding time at this temperature is advantageously 2 hours and can exceed this value by 20%.

[0073] The reprecipitation S06' is obtained by controlling the cooling. This cooling can be carried out in the oven up to 1080 °C at a rate of 47 to 67 °C / h, preferably 52 to 62 °C / h, for example 57 °C / h; then from 1080 °C to 540 °C at a rate greater than or equal to 16 °C / min to finish in air after 540 °C.

[0074] Tempering S07 provides a slight improvement in tensile properties. When this improvement is not desired, it is unnecessary to perform it. It can be achieved by heating the alloy to a temperature of 750 to 770 °C, preferably 755 to 765 °C, for example 760 °C. The holding time for this heating is typically 4 hours and can exceed this value by 20%. When this treatment is stopped, the alloy is simply exposed to air.

[0075] A stress relief S04 allowing the removal of stresses which would remain inside the matrix of the alloy can be carried out before the first treatment applied among the treatments producing the service condition.

[0076] This S04 release is typically carried out under the same conditions described above for the S07 release.

[0077] This S08 de-stressing can alternatively or additionally be carried out after the S07 return.

[0078] These treatments make it possible to achieve an HV hardness of 350 to 475 HV and properties at the expected levels (in particular: no impact on physical properties such as density, Poisson's ratio, Young's modulus, Thermal expansion, electrical / thermal conductivity, and specific heat capacity; and cracking properties; as well as an increase in tensile, finishing, and fatigue properties) are of interest for parts designed with microcracking eliminated or at least significantly limited. A slight anisotropy may be observed. This is typical of laser powder bed fusion and is not problematic for the alloy's properties. The addition of the oxide allows for a gain of approximately 30% in tensile, finishing, and fatigue properties at 1100°C and prevents any drop in alloy properties up to 1150°C (compared to 1050°C for the best alloys currently available, such as René 77 without oxide).

[0079] The present invention also provides an aeronautical part manufactured from the alloy described above. This part is formed directly during the melting process described above. The aeronautical part may be, in particular, a turbine distributor, a retaining ring, a sealed sector (OSAS), an injection system, a fairing part, or a turbine blade.

Claims

Demands

1. Nickel-based alloy powder composed of 0.2 to 5% Y2O3 oxide, the remainder of the powder having the following composition: 0.050 to 0.090% C; 14.25 to 15.75% Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% Mo; 3.00 to 3.70% Ti; 0.012 to 0.020% B; 0 to 0.50% Fe; 0 to 0.060% Zr; 0 to 0.150% Mn; 0 to 0.20% Si; 0 to 0.10% Cu; 0 to 25 ppm S; 0 to 0.5 ppm Bi; 0 to 5 ppm of Ag; 0 to 5 ppm of Pb; 0 to 60 ppm of N2; and 0 to 200 ppm of O; Ni making up the balance of the composition; given that the percentages and ppm mentioned above are given relative to the total of the rest of the powder.

2. Alloy powder according to claim 1, composed of two populations of particles: Y2O3 oxide particles (PO) and metallic particles (PM) constituting the remainder of the powder.

3. Alloy powder according to claim 1, wherein the Y2O3 (PO) oxide particles have dimensions ranging from 50 to 500 nm.

4. Alloy powder according to claim 1, wherein the particles have a metallic core (CM) made up of the composition and a surface layer (CS) made up of Y2O3 oxide around the metallic core.

5. Alloy powder according to any one of claims 4, having the following particle size profile: D10 from 10 to 25 µm; D50 from 25 to 40 µm; and D90 from 40 to 70 pm.

6. Alloy powder according to any one of claims 1 to 5, wherein the alloy powder particles have a substantially spherical shape.

7. Nickel-based alloy comprising: 0.050 to 0.090% C; 14.25 to 15.75% Co; 14.00 to 15.25% Cr; 4.00 to 4.60% Al; 3.90 to 4.50% Mo; 3.00 to 3.70% Ti; 0.012 to 0.020% B; 0 to 0.50% Fe; 0 to 0.060% Zr; 0 to 0.150% Mn; 0 to 0.20% Si; 0 to 0.10% Cu; 50 to 1000 ppm Y; 0 to 25 ppm S; 0 to 0.5 ppm Bi; 0 to 5 ppm Ag; 0 to 5 ppm Pb; 0 to 100 ppm of N2; 0 to 1000 ppm of O; 0 to 500 ppm of Pt; and 0 to 500 ppm of V; Ni making up the balance of the rest of the composition; given that the percentages and ppm mentioned above are given in relation to the weight of the total composition; the quantity of each of the other elements, called traces, being limited to 50 ppm with a total limited to 500 ppm.

8. A process for producing the alloy according to claim 7 from the powder according to any one of claims 1 to 6, the process comprising: the production (SOI) of the powder by atomization; the melting (SO2) of the powder by laser powder bed fusion.

9. Method according to claim 8, further comprising after melting, hot isostatic compaction (SO3).

10. A process according to claim 8 or claim 9, further comprising at least one of the treatments producing the following use state: grain growth (S05); resuspension (S06) and reprecipitation (S06'); and tempering (S07).

11. A method according to claim 10, comprising a detensioning (S04, S08) before the first of the treatments producing the use state or after the last of the treatments producing the use state.

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