Fabrication of metallic parts by additive manufacturing

1. A method of fabricating a three-dimensional part comprising a metallic material, the method comprising:

(a) providing a wire comprising arc-melted metallic material, wherein the wire is produced by a process comprising (i) in a processing ambient comprising a vacuum or one or more inert gases, arc-melting a feed electrode comprising the metallic material to thereby form a billet, and (ii) mechanically deforming the billet into wire having a diameter less than a diameter of the billet;

(b) translating a tip of the wire relative to a platform;

(c) while the tip of the wire is being translated, melting the tip of the wire with an energy source to form a molten bead, whereby the bead cools to form at least a portion of a layer of a three-dimensional part; and

(d) repeating steps (b) and (c) one or more times to produce the three-dimensional part,

wherein the three-dimensional part comprises the metallic material.

2. The method of claim 1 , wherein the metallic material comprises at least one of niobium, tantalum, rhenium, tungsten, or molybdenum.

3. The method of claim 1 , wherein a concentration within the wire of at least one of sodium, calcium, antimony, magnesium, phosphorous, or potassium is less than 5 ppm by weight.

4. The method of claim 1 , wherein a concentration of oxygen within the wire is less than 20 ppm by weight.

5. The method of claim 1 , wherein a density of the three-dimensional part is greater than 97% of a theoretical density of the metallic material.

6. The method of claim 1 , wherein in step (c) the energy source comprises an electron beam and/or a laser beam.

7. A method of fabricating a three-dimensional part comprising a metallic material, the method comprising:

(a) providing a wire comprising arc-melted metallic material;

(b) translating a tip of the wire relative to a platform;

(c) while the tip of the wire is being translated, melting the tip of the wire with an energy source to form a molten bead, whereby the bead cools to form at least a portion of a layer of a three-dimensional part; and

(d) repeating steps (b) and (c) one or more times to produce the three-dimensional part,

wherein the three-dimensional part comprises the metallic material, and the wire is produced by a process comprising:

compacting powder to form a feed electrode, the powder comprising the metallic material;

arc-melting the feed electrode in a processing ambient comprising a vacuum or one or more inert gases, thereby forming a billet; and

mechanically deforming the billet into wire having a diameter less than a diameter of the billet.

8. The method of claim 7 , wherein the metallic material comprises at least one of niobium, tantalum, rhenium, tungsten, or molybdenum.

9. The method of claim 7 , wherein a concentration within the wire of at least one of sodium, calcium, antimony, magnesium, phosphorous, or potassium is less than 5 ppm by weight.

10. The method of claim 7 , wherein a concentration of oxygen within the wire is less than 20 ppm by weight.

11. The method of claim 7 , wherein a density of the three-dimensional part is greater than 97% of a theoretical density of the metallic material.

12. The method of claim 7 , wherein in step (c) the energy source comprises an electron beam and/or a laser beam.

13. The method of claim 7 , wherein mechanically deforming the billet comprises at least one of drawing, rolling, swaging, extruding, or pilgering.

14. The method of claim 7 , wherein the wire-production process comprises sintering the compacted powder at a temperature greater than 900° C.

15. The method of claim 7 , wherein the wire-production process comprises providing the powder by a process comprising at least one of plasma densification or plasma atomization.

16. The method of claim 7 , wherein the wire-production process comprises:

hydrogenating metal to form a metal hydride;

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

dehydrogenating the metal hydride particles.

17. The method of claim 1 , wherein mechanically deforming the billet comprises at least one of drawing, rolling, swaging, extruding, or pilgering.