EP4058224A1

EP4058224A1 - Spherical powder for making 3d objects

Info

Publication number: EP4058224A1
Application number: EP20807361.9A
Authority: EP
Inventors: Markus Weinmann; Holger Brumm; Christoph Schnitter
Original assignee: Taniobis GmbH
Current assignee: Taniobis GmbH
Priority date: 2019-11-15
Filing date: 2020-11-13
Publication date: 2022-09-21
Also published as: AU2020382062A1; KR20220099107A; IL292769A; CN114641357A; JP2023502935A; BR112022006007A2; TW202132579A; US20220395900A1; WO2021094560A1; DE102019217654A1; CA3157126A1

Abstract

The present invention relates to spherical alloy powders composed of at least two refractory metals, the alloy powder having a homogeneous microstructure and comprising at least two different crystalline phases, and to a method for producing such powders. The present invention further relates to the use of such powders in the making of three-dimensional components and to a component produced from such a powder.

Description

Spherical powder for the production of three-dimensional objects

The present invention relates to spherical alloy powders made from at least two refractory metals, the alloy powder having a homogeneous microstructure and at least two different crystalline phases, and a method for producing such powders. The present invention further relates to the use of such powders in the production of three-dimensional components and to a component made from such a powder.

Various processes are available for the production of metallic components with complex geometry. On the one hand, such components can be manufactured using additive manufacturing, also known as 3D printing. The term "additive manufacturing" encompasses all manufacturing processes in which three-dimensional objects are manufactured by applying material in layers under computer control and connecting the layers to one another, usually through physical and chemical hardening or melting processes. Additive manufacturing processes are particularly notable due to their high precision and shape accuracy and enable models and samples to be produced quickly and inexpensively. Another option for producing metallic components is metal injection molding (MIM), which has its origins in the injection molding technology of plastics a fine metal powder is mixed with an organic binder and placed in a mold using an injection molding machine, the binder is then removed and the component sintered, allowing the mechanical advantages to be sintered ter components with the great variety of shapes of injection molding. As a further advantage, the process offers the possibility of producing components with complex geometries, which conventional processes can only be manufactured in several parts, in a single piece.

Common materials for use in additive manufacturing processes and injection molding processes are plastics, synthetic resins, ceramics and metals. While there is now a wide variety of plastic materials that are routinely used in these processes, there continues to be a need in the metals art for suitable powders, particularly a good one Must have flowability and high sintering activity in order to be able to be processed into stable and durable objects.

WO 2011/070475 describes a method for producing an alloy with at least two refractory metals, according to the method, the two refractory metals are melted and mixed in a crucible by applying an electron beam and the melt is solidified, the molten metals for solidification with a Cooling rate in a range of 200 Ks ¹ to 2000 Ks ^{1 can be} quenched. It is recommended to provide the two metals in the form of a powder and to mix them with one another before melting in order to achieve a complete solution of the two metals in one another. It is particularly important that the two metals form a solid solution in any composition and that a second phase is prevented from occurring. However, the method described has the disadvantage that a large amount of impurities is introduced into the powder through the use of the melting crucible and the high temperatures required.

US 2019/084048 discloses a method for producing atomized, spherical β-Ti / Ta alloy powders for additive manufacturing, comprising the following steps: a) mixing elemental Ti and Ta powders to form a Ti-Ta powder composition; b) hot isostatic pressing of the

Powder composition for forming a Ti / Ta electrode and c) treating the Ti / Ta electrode by means of EIGA in order to obtain an atomized, spherical Ti / Ta alloy powder. However, the method described has the disadvantage that the powders obtained have an inhomogeneous microstructure, which can be undesirable for some applications.

CN 108296490 provides a manufacturing method for spherical tungsten-tantalum alloy powder in which an irregularly shaped tungsten-tantalum mixed powder prepared using a high energy ball milling method is used as raw material. The raw powder used is shaped into the desired alloy powder by means of plasma spheroidization. As is known, the grinding process used has the disadvantage of undesirable introduction of abrasion from the grinding balls. The processes described in the prior art for the production of alloy powders have the disadvantage that in some cases high proportions of foreign particles are introduced into the powder during the production process and the powders have a dendritic element distribution, which in turn can have a negative effect on the quality of the components, which are made from these powders, since the components have to be sintered for a longer period of time and usually also at a higher temperature in order to obtain the desired mechanical strength. It is therefore the object of the present invention to overcome the disadvantages of the prior art and to provide a powder which enables the production of pore-free and mechanically stable components, in particular components with complex geometry that are suitable for high-temperature applications.

It has surprisingly been found that this object is achieved by a powder which consists of an alloy of at least two refractory metals and has a homogeneous microstructure and at least two different crystal phases.

Therefore, a first object of the present invention is a spherical powder for the production of three-dimensional components, the powder being an alloy powder composed of at least two refractory metals, the alloy powder having a homogeneous microstructure and at least two different crystalline phases.

The powder according to the invention is characterized by good flowability and high sintering activity, which enables the production of pore-free and mechanically stable components by means of additive manufacturing and / or injection molding.

In the context of the present invention, the expression “alloy powder” is to be regarded as synonymous with the powder according to the invention, unless otherwise indicated.

Refractory metals in the context of the present invention are the refractory metals of the third, fourth, fifth and sixth subgroups of the periodic table of the elements. These metals stand out In addition to their high melting point, they have a passivation layer at room temperature.

In the context of the present invention, the term “alloy powder” denotes a powder in which the refractory metals are present in the form of an alloy and form a macroscopically homogeneous powder. These powders are in contrast to mixed powders in which the components are individually present in the form of a mixture and macroscopically there is an inhomogeneous distribution of elements.

“Homogeneous microstructure” in the context of the present invention is understood to mean a homogeneous distribution of elements, that is to say a uniform distribution and spatial filling of the alloy components in the individual powder particles without macroscopic fluctuations from place to place.

In the context of the present application, the term particle size denotes the longest linear dimension of a powder particle from one end to the opposite end of the particle. Agglomerates in the context of the present invention are understood as solidified accumulations of previously loose powder particles. The previously loose particles, which are formed into agglomerates by means of sintering, for example, are referred to as primary particles.

The use of additive manufacturing methods and MIM extends to almost all areas of industry. The properties of the manufactured components can be influenced by the powders used, whereby, in addition to the mechanical properties of the components, other properties such as optical and electronic properties can also be adapted.

Therefore, an embodiment of the powder according to the invention is preferred in which the refractory metals are those selected from the group consisting of tantalum, niobium, vanadium, yttrium, titanium, zirconium, hafnium, tungsten and molybdenum. In a particularly preferred embodiment, the at least two refractory metals are tantalum and tungsten. In a particularly preferred embodiment, the alloy powder according to the invention is free of Ti. In this case, the proportion of titanium in the alloy powder according to the invention is particularly preferably less than 1.5% by weight, particularly preferably less than 1.0% by weight, in particular at less than 0.5% by weight and especially at less than 0.1% by weight, based in each case on the total weight of the alloy powder.

The powder according to the invention is particularly characterized in that the alloy powder has at least two different crystal phases. It has been found to be particularly advantageous if one of these crystal phases is a metastable crystal phase. In this context, a metastable crystal phase is understood to mean a phase that is thermodynamically unstable at room temperature. The crystal phases occurring in the alloy powder according to the invention can be determined, for example, with the aid of X-ray diffraction analyzes (RBA) and differentiated on the basis of their reflections in the X-ray diffraction program. The distribution of the different crystal phases in the powder can vary. A preferred embodiment of the present invention is characterized in that one crystal phase makes up a larger proportion than the other crystal phases. This phase with the largest proportion is referred to as the main crystal phase, while phases with a smaller proportion are referred to as secondary crystal phases or secondary phases. The powder according to the invention preferably has a main crystal phase and at least one secondary crystal phase. It was surprisingly found that the ratio of the phases has an influence on the mechanical properties of a later component, the ratio of the phases being able to be determined by means of their reflection intensities in the X-ray diffraction program, indicated there as pulses per angle [° 2Theta]. In a particularly preferred embodiment, the ratio of the reflex with the highest intensity of the at least one secondary phase (I (P2) 100) and the reflex with the highest intensity of the main crystal phase (I (P1) 100), expressed as I (P2) 100 / I (P1) 100, preferably less than 0.75, particularly preferably 0.05 to 0.55, in particular 0.07 to 0.4, each determined by means of X-ray diffractometry.

Another aspect that distinguishes the powder according to the invention is its homogeneous microstructure. As a rule, alloy powders, in particular of refractory metals, have the disadvantage that the various alloy components are inhomogeneously distributed in the individual powder particles due to the manufacturing process, since the residence time of the particles is usually too short to allow sufficient mixing and diffusion of the individual components to reach. This inhomogeneous distribution has disadvantages in particular for the mechanical properties of the components made from these powders, which can only be compensated for by using a significantly higher energy input, for example in the SLM process with a significantly higher laser power or lower scanning speed of the laser in the manufacturing process can. In the context of the present invention, however, it was surprisingly found that the powders themselves already have a homogeneous distribution of the alloy constituents. Therefore, an embodiment of the powder according to the invention is preferred in which in at least 95%, preferably in at least 97%, particularly preferably in at least 99% of all powder particles, the content of the alloying elements, expressed in% by weight, within a particle by less than 8% vary, preferably by 0.05 to 6%, particularly preferably 0.05 to 3%, determined by means of EDX (energy dispersive X-ray spectroscopy). The powder according to the invention is characterized in particular by its sphericity, which makes it particularly suitable for use in additive manufacturing processes and injection molding processes. An embodiment is therefore preferred in which the powder particles have an average aspect ratio Y _A of 0.7 to 1, preferably 0.8 to 1, particularly preferably 0.9 to 1 and in particular 0.95 to 1, Y _{A being} defined than the ratio of the minimum Ferret

Diameter to the maximum Ferret diameter, expressed as Y _A = x Fen-et min / x Ferret max- The Ferret diameter denotes the distance between two tangents of a particle at any angle. The maximum Ferret diameter x _Ferret max9o can be determined by first determining the maximum Ferret diameter and then determining the Ferret diameter, which is offset by an angle of 90 ° to this maximum Ferret diameter. This also applies to the determination of the minimum Ferret diameter. The Ferret diameter of a particle can be determined, for example, by means of image evaluation methods from scanning electron microscope images (SEM images) (see also FIG. 9 in this regard).

In addition to sphericity, the flowability of a powder is another criterion that defines its suitability for use in additive manufacturing processes in particular. The powder according to the invention is characterized by a flowability which is adapted to the requirements in these manufacturing processes is adapted. Therefore, an embodiment of the powder according to the invention is preferred in which the powder has a flowability of less than 25s / 50g, preferably less than 20s / 50g and in particular less than 15s / 50g, each determined in accordance with ASTM B213.

Furthermore, the powder according to the invention is characterized by a high tap density, a further criterion that should be taken into account when choosing a powder for use in such manufacturing processes. In a preferred embodiment, the powder according to the invention has a tap density of 40 to 80% of its theoretical density, preferably 60 to 80% of its theoretical density, in each case determined in accordance with ASTM B527.

It is known that the mechanical properties and the porosity of components that are manufactured by means of such manufacturing processes can be controlled, inter alia, by the particle size of the powders used, the particle sizes should be selected depending on the respective manufacturing process, in particular a narrow one Particle size distribution has proven beneficial. In a preferred embodiment of the present invention, the powder according to the invention has a particle size distribution with a D10 value of greater than 2 pm, preferably greater than 5 pm and a D90 value of less than 80 pm, preferably less than 70 pm with a D50 value of 20 up to 50 pm, preferably 25 to 50 pm, each determined in accordance with ASTM B822. This particle size distribution has proven to be particularly advantageous for selective laser melting (SLM) processes.

In a further preferred embodiment, the D10 value of the particle size distribution of the powder according to the invention is more than 20 μm, preferably more than 50 μm, and the D90 value is less than 150 μm, preferably less than 120 μm, with a D50 value of 40 up to 90 pm, preferably 60 to 85 pm, each determined in accordance with ASTM B822. In particular in the area of the electron beam melting process (EBM), a particle size distribution as indicated has proven to be particularly advantageous.

In a further preferred embodiment, the powder according to the invention has a particle size distribution with a D10 value of more than 50 μm, preferably more than 80 μm and a D90 value of less than 240 μm, preferably less than 210 μm, with a D50 value from 60 to 150 pm, preferably 100 to 150 μm, each determined in accordance with ASTM B822. Powders with such a particle size distribution have proven to be particularly advantageous when using laser cladding processes (CL).

In a further preferred embodiment, the powder according to the invention has a particle size distribution with a D10 value of more than 1 μm, preferably more than 2 μm and a D90 value of less than 45 μm, preferably less than 40 μm, with a D50 value from 6 to 30 pm, preferably 8 to 20 pm, in each case determined in accordance with ASTM B822. In particular when using such powders in injection molding processes such as metal injection molding (MIM), a particle size distribution in the specified range has proven to be advantageous.

In the context of the present invention, the D50 value is to be understood as the mean particle size, with 50% of the particles being smaller than the values given. The same applies to the D10, D90 and D99 values. Another object of the present invention is a method for producing the alloy powder according to the invention. The method according to the invention comprises the following steps: a) Providing a starting powder mixture comprising at least two refractory metals, the starting powder mixture having a particle size with a D99 value of less than 100 μm and at least one of the refractory metals having a particle size with a D99 value of less than 10 pm, each determined in accordance with ASTM B822; b) producing a powder body from the starting powder mixture by means of cold isostatic pressing (CIP); c) sintering the pressed body at a temperature which is 400 to 1150 ° C., preferably 700 to 1050 ° C. below the lowest melting point of the components of the starting powder mixture; d) melting the sintered body by means of electrode induction melting (EIGA); and e) atomizing the melt with simultaneous cooling to obtain a spherical alloy powder. It has surprisingly been found that the method according to the invention gives spherical powders with a narrow particle size distribution and high sintering activity, which allow the production of pore-free and mechanically stable components by means of additive manufacturing processes or MIM. The powders produced with the method according to the invention are furthermore distinguished by a homogeneous distribution of the alloy constituents and the presence of at least two crystal phases.

The compression (CIP) of the powder is preferably carried out at a compression pressure of at least 1.7-10 ⁸ Pa (1700 bar), particularly preferably at least 1.9-10 ⁸ Pa (1900 bar).

In a preferred embodiment, the method according to the invention further comprises a classification step, preferably sieving. In this way, the desired particle size distribution can be adapted and set.

In a further preferred embodiment, the starting powder mixture has a particle size with a D99 value of less than 100 μm, preferably less than 80 μm, in each case determined by means of ASTM B822.

In a preferred embodiment, at least one of the refractory metals in the starting powder mixture has a particle size with a D99 value of less than 10 μm, preferably less than 5 μm, particularly preferably less than 2 μm, in each case determined by means of ASTM B822, which is preferably is the refractory metal with the highest melting point.

It has been found to be advantageous if refractory metals are used in the starting powder mixture, the primary particles of which have been sintered to form porous agglomerates, in particular those refractory metals which have a primary particle size of less than 10 μm, preferably less than 3 μm, particularly preferably less than 1 μm have, determined by means of image evaluation methods from scanning electron microscope images (SEM images). An embodiment is therefore preferred in which at least one refractory metal of the starting powder mixture is in the form of sintered, porous agglomerates with a particle size with a D99 value of less than 100 mpΊ, preferably less than 80 pm, determined according to ASTM B822, and which has a primary particle size of less than 10 pm, preferably less than 3 pm, particularly preferably less than 1 pm, determined by means of SEM images.

The sintering in step c) of the method according to the invention is carried out at a temperature which is 400 to 1150 ° C., preferably 700 to 1050 ° C., below the melting point of the alloy component with the lowest melting point, the melting points of the alloy components being known to the person skilled in the art or can be found in the literature. The duration of the sintering process can be adapted according to the required properties of the powder, but is preferably 0.5 to 6 hours, particularly preferably 1 to 5 hours.

In the context of the present invention, refractory metals with a high melting point are preferably used. Therefore, the sintering is preferably carried out at a temperature of at least 1400 ° C.

It has been shown that for some applications a high oxygen content in the alloy powder has a negative effect on its use in certain manufacturing processes. An embodiment of the method according to the invention is therefore preferred in which the alloy powder is furthermore subjected to a deoxidation step in the presence of a reducing agent, magnesium or calcium, in particular in the form of steam, being used as the reducing agent. A person skilled in the art can find a detailed description of a suitable deoxidation process in patent specification EP 1 144 147, for example.

In order to keep the oxygen content of the powder according to the invention as low as possible during the production process, it has proven to be advantageous if the cooling takes place in a low-oxygen environment. An embodiment is therefore preferred in which the cooling takes place during the atomization by means of cooled inert gas.

For special applications, however, a specific adjustment of the oxygen content is desirable. In a preferred embodiment, the starting powder mixture is therefore an oxygen-containing component of the Refractory metals, such as, for example, their oxides or sub-oxides, added in order to set a desired oxygen content in the powders according to the invention in a targeted manner.

Surprisingly, it has been shown that the powders according to the invention can be used not only in additive manufacturing processes, but also for the manufacture of three-dimensional components by means of metal injection molding (MIM). The present invention therefore also relates to the use of the powder according to the invention or a powder obtained according to the method according to the invention in additive manufacturing processes and / or metal injection molding processes. The additive manufacturing process is preferably one that is selected from the group consisting of Selective Laser Melting (SLM), Electron Beam Melting (EBM) and Laser Deposition Welding (LC).

Another object of the present invention is a component which was produced using the alloy powder according to the invention or a powder obtained by means of the method according to the invention. The component is preferably a component that is used in high-temperature applications, for example in the context of engines and high-temperature furnaces. Alternatively, the component is preferably a medical implant or device.

Examples:

The present invention is explained in more detail with reference to the following examples, which are in no way to be understood as a restriction of the inventive concept.

Powders Ta2.5W (E1) and Tal3W (E2) according to the invention were produced, the particle size D99 of the tantalum powder used being 49 μm and that of the tungsten powder being 1.9 μm in the starting powder mixtures, each measured in accordance with ASTM B822. The powders were shaped into a compact by means of cold isostatic pressing (CIP) at a pressing pressure of 2000 bar, which was sintered at 1950 ° C. for 2 hours. The sintered body obtained in this way was melted by means of electrode induction melting (EIGA) and the melt was atomized while cooling at the same time. According to the classification of the atomized powder by sieving into two fractions (<63mhi, 63-100mhi) the alloy powders obtained <63mhi were deoxidized at 1000 ° C. for two hours in the presence of Mg. The compositions and properties of the powders obtained are summarized in Table 1, the parameters in each case being determined according to the standards given above.

The oxygen and nitrogen content of the powder was determined by means of hot carrier gas extraction (Leco TCH600) and the particle sizes in each case by means of laser diffraction (ASTM B822, MasterSizer S, dispersion in water and Daxad 11, 5 min ultrasound treatment). The trace analysis of the metallic impurities was carried out by means of ICP-OES with the following analysis devices PQ 9000 (Analytik Jena) or Ultima 2 (Horiba). The crystal phases were determined by means of X-ray diffraction (RBA) using a device from Malvern-PANalytical (X ^' Pert-MPD with semiconductor detector, X-ray tube Cu LFF with 40KV / 40mA, Ni filter) Table 1:

In the case of the powders according to the invention, two different crystalline phases could be identified in the X-ray diffractogram, a cubic main crystal phase and a tetragonal secondary crystal phase, as can also be seen from FIGS. 1 and 2, the recordings of the powders according to the invention Ta2.5W (FIG. 1) and Tal3W (FIG 2) show. The determined ratios of the reflex intensities for the reflexes with the highest intensities in each case are given in Table 1.

Further recordings of the powder Tal3W from experiment E2b show that, in contrast to conventional powders, no dendritic structures can be seen and the powder particles are spherical. For this purpose, FIG. 3 shows an EDX recording on a ground sample of the powder Tal3W, while FIG. 4 shows the spherical shape of the powder particles of Tal3W on the basis of an SEM image on a litter preparation.

For comparison purposes, a powder Ta2.5W (cf.) was produced according to the conventional process by first producing a fusible ingot using an electron beam. This was embrittled by hydrogenation with hydrogen and ground. The hydrogen was removed in a high vacuum and the material was sieved to a value of less than 63 μm. The corresponding results are summarized in Table 2. As X-ray diffraction analyzes and SEM images show, the powder obtained had neither two different crystal phases nor a spherical morphology (see FIGS. 5a and 5b).

Table 2: As a further comparison, a powder Ta2.5W (Vg2) was produced by pressing the corresponding starting powder and sintering it at 1200 ° C. to form a metal body which was then atomized. The particle sizes D99 of the Starting metals Ta and W were 150 pm and 125 pm, respectively. The results are also summarized in Table 2.

A third comparison powder was produced analogously to comparison 2, but 13% by weight of W was used (Vg3, see table 2). As FIG. 6a clearly shows, the powder according to Vg3 has a dendritic microstructure, the variation of the tantalum and tungsten contents being represented by different gray levels and being up to 15% by weight in the areas marked 1 to 4. A second crystal phase could not be identified (see FIG. 6b). As the comparative experiments show, no powders with a homogeneous microstructure or elementary distribution which simultaneously have two different crystal phases can be obtained with known methods.

The powder according to comparison 3 (Vg3) and the powder E2b according to the invention were printed using the SLM with the printing parameters indicated in table 3. A dense, cube-shaped component with an edge length of approx. 2.5 cm and a homogeneous microstructure should be produced. The density of the component is given as the ratio of the actually measured density of the component to the theoretical density of the alloy in%. A density of less than 100% indicates the presence of unwanted pores, which can have a negative impact on the mechanical properties of the component.

The component produced with the powder according to the invention could be obtained in the required density even at low laser power or volumetric energy density, which among other things leads to increased process reliability, lower energy consumption and lower oxygen uptake of the remaining powder. Alternatively, the scanning speed of the laser could be increased so that a higher throughput was achieved.

Table 3:

FIG. 7 shows an SEM image of a ground sample of the component (D3) produced with the powder E2b according to the invention with a density of 99% of the theoretical density. FIG. 8 shows an SEM image of a ground sample of a component D1 which was produced with the comparison powder V3b. The low density of the component of less than 80% of the theoretical density can be clearly seen.

Claims

Patent claims:

1 . Spherical powder for the production of three-dimensional components, characterized in that the powder is an alloy powder composed of at least two refractory metals, the alloy powder having a homogeneous microstructure and at least two crystalline phases.

2. Powder according to claim 1, characterized in that the refractory metals are tantalum, niobium, vanadium, yttrium, titanium, zirconium, hafnium, tungsten and molybdenum, preferably tungsten and tantalum.

3. Powder according to at least one of claims 1 to 2, characterized in that the alloy powder is essentially free of Ti, the content of Ti in the alloy powder preferably being less than 1.5% by weight, particularly preferably less than 1, 0% by weight, in particular at less than 0.5% by weight and especially at less than 0.1% by weight.

4. Powder according to at least one of claims 1 to 3, characterized in that one of the crystal phases is a metastable crystal phase.

5. Powder according to at least one of claims 1 to 4, characterized in that the powder has a main crystal phase and at least one secondary crystal phase, the intensity ratio of the reflection from an X-ray diffractogram with the highest intensity of at least one secondary crystal phase (I (P2) 100) and the highest intensity of the main crystal phase (I (P1) 100), expressed as I (P2) 100 / I (P1) 100, preferably less than 0.75, particularly preferably 0.05 to 0.55, in particular 0.07 to 0, 4, each determined by means of X-ray diffractometry.

6. Powder according to at least one of claims 1 to 5, characterized in that in at least 95%, preferably at least 97%, particularly preferably at least 99% of all powder particles, the content of the alloying elements, expressed in% by weight, within a particle is less than 8%, preferably by 0.05 to 6%, particularly preferably 0.05 to 3%, determined by means of EDX (energy dispersive X-ray spectroscopy).

7. Powder according to at least one of claims 1 to 6, characterized in that the powder has a flowability of less than 25 s / 50g, preferably less than 20 s / 50g and in particular less than 15 s / 50g, each determined in accordance with ASTM B213 .

8. Powder according to at least one of claims 1 to 7, characterized in that the powder has a tap density of 40 to 80% of its theoretical density, preferably 60 to 80% of its theoretical density, each determined in accordance with ASTM B527.

9. A method for producing spherical alloy powders according to at least one of claims 1 to 8 comprising the steps of a) providing a starting powder mixture comprising at least two refractory metals, the starting powder mixture having a particle size with a D99 value of less than 100 μm and at least one of the refractory metals having a particle size with a D99 value of less than 10 gm, each determined in accordance with ASTM B822. b) producing a powder body from the starting powder mixture by means of cold isostatic pressing (CI P); c) sintering the pressed body at a temperature which is 400 to 1150 ° C., preferably 700 to 1050 ° C. below the lowest melting point of the refractory metals of the starting powder mixture; d) melting the pressed powder body by means of electrode induction melting; e) atomizing the melt with simultaneous cooling to obtain a spherical alloy powder.

10. The method according to claim 9, characterized in that one of the

Refractory metals of the starting powder mixture in the form of porous

Agglomerates with a particle size D99 of less than 100 μm, determined according to ASTM B822, is present.

11. The method according to claim at least one of claims 9 and 10, characterized in that the sintering is carried out for a period of 0.5 to 6 hours, preferably 1 to 5 hours.

12. The method according to at least one of claims 9 to 11, characterized in that the alloy powder further a

Deoxidation step is subjected in the presence of a reducing agent, the reducing agent preferably being magnesium or calcium, in particular in the form of steam.

13. The method according to at least one of claims 9 to 12, characterized in that the cooling takes place during the atomization by means of cooled inert gas.

14. Use of an alloy powder according to at least one of claims 1 to 8 or a powder obtainable by a method according to at least one of claims 9 to 13 in additive manufacturing processes and / or metal powder injection molding processes (MIM).

15. Use according to claim 14, characterized in that the additive manufacturing process is a process selected from the group consisting of Selective Laser Melting (SLM), Electron Beam Melting (EBM) and laser deposition welding (LC).

16. Component produced using an alloy metal powder according to at least one of claims 1 to 8 or a powder obtainable by a method according to at least one of claims 9 to 13.