Fabrication of high-entropy alloy wire and multi-principal element alloy wire

1. A method of fabricating a metallic wire comprising a high-entropy alloy comprising five or more metallic elements or a multi-principal element alloy comprising four or more metallic elements, the method comprising:

providing a metallic tube comprising at least one of the metallic elements of the high-entropy alloy or the multi-principal element alloy; and

combining, within the metallic tube, (i) one or more first metal powders each comprising a plurality of substantially spherical particles, and (ii) one or more second metal powders each comprising a plurality of non-spherical particles, the one or more second metal powders being mixed with the one or more first metal powders, thereby forming a wire preform,

wherein (i) each first metal powder comprises at least one of the metallic elements of the high-entropy alloy or the multi-principal element alloy, (ii) each second metal powder comprises at least one of the metallic elements of the high-entropy alloy or the multi-principal element alloy, (iii) the substantially spherical particles are spherical to within ±10% in any direction such that an eccentricity in any direction does not exceed 10%, and (iv) the non-spherical particles (a) are elongated with an aspect ratio of at least 2:1, (b) are acicular, (c) have at least one flat surface, (d) are flakes, (e) have at least one corner or vertex, or (f) are polyhedral.

2. The method of claim 1 , further comprising reducing a diameter of the wire preform via one or more mechanical deformation processes.

3. The method of claim 2 , wherein the one or more mechanical deformation processes comprise at least one of drawing, pilgering, swaging, extrusion, or rolling.

4. The method of claim 2 , further comprising:

providing one or more sacrificial tubes around the metallic tube; and

removing the one or more sacrificial tubes from the wire preform after the diameter of the wire preform is reduced.

5. The method of claim 1 , wherein the metallic elements comprise at least four of Nb, Ta, Mo, W, Ti, Hf, V, Zr, Al, or Cr.

6. The method of claim 1 , wherein at least one first metal powder is an elemental powder consisting essentially of one of the metallic elements.

7. The method of claim 1 , wherein at least one first metal powder is an alloy powder consisting essentially of two or more of the metallic elements.

8. The method of claim 1 , wherein at least one second metal powder is an elemental powder consisting essentially of one of the metallic elements.

9. The method of claim 1 , wherein at least one second metal powder is an alloy powder consisting essentially of two or more of the metallic elements.

10. The method of claim 1 , wherein the metallic tube consists essentially of one of the metallic elements.

11. The method of claim 1 , wherein the metallic tube is an alloy tube consisting essentially of two or more of the metallic elements.

12. The method of claim 1 , wherein the non-spherical particles of at least one second metal powder are angular flakes.

13. The method of claim 1 , wherein an oxygen concentration of the one or more first metal powders is 300 ppm or less.

14. The method of claim 1 , wherein an oxygen concentration of the one or more second metal powders is 300 ppm or less.

15. The method of claim 1 , wherein at least one said first metal powder is provided by a process comprising:

providing a plurality of metal particulates;

feeding the metal particulates into a plasma, thereby at least partially melting the metal particulates; and

cooling the at least partially melted metal particulates to form substantially spherical particles.

16. The method of claim 1 , wherein at least one said second metal powder is provided by a process comprising:

hydrogenating metal to form a metal hydride;

mechanically grinding the metal hydride into a plurality of non-spherical particles; and

dehydrogenating the non-spherical metal hydride particles.

17. The method of claim 1 , wherein an average particle size of at least one of the first metal powders ranges from approximately 15 μm to approximately 45 μm.

18. The method of claim 1 , wherein an average particle size of at least one of the second metal powders is greater than approximately 50 μm.

19. The method of claim 1 , further comprising:

translating a tip of the wire relative to a platform;

thereduring, melting a tip of the wire with an energy source to form a molten bead comprising the metallic elements, whereby the bead cools to form at least a portion of a layer of a three-dimensional part; and

repeating the above steps one or more times to produce the three-dimensional part,

wherein the three-dimensional part comprises the high-entropy alloy or the multi-principal element alloy.

20. The method of claim 1 , further comprising:

providing one or more sacrificial tubes around the metallic tube before the one or more first metal powders and the one or more second metal powders are combined; and

removing the one or more sacrificial tubes from the wire preform.