Methods for forming oxide dispersion-strengthened alloys
In accordance with an exemplary embodiment, a method of forming a oxide dispersion-strengthened alloy metal includes the steps of providing, in a powdered form, an oxide dispersion-strengthened alloy composition that is capable of achieving a dispersion-strengthened microstructure, directing a low energy density energy beam at a portion of the alloy composition, withdrawing the energy beam from the portion of the powdered alloy composition, and cooling the portion of the powdered alloy composition at a rate greater than or equal to about 10 6 ° F. per second, thereby forming the oxide dispersion-strengthened alloy metal.
1. A method of forming an oxide dispersion-strengthened alloy metal comprising the steps of:
providing, in a powdered form, an oxide dispersion-strengthened alloy composition that is capable of achieving a dispersion-strengthened microstructure, wherein providing the oxide dispersion-strengthened alloy composition in powdered form comprises mixing a plurality of metals and oxides forming the alloy to form a mixture, melting the mixture to form a melted mixture, and atomizing the melted mixture into the powdered form;
directing a low energy density energy beam at a portion of the alloy composition, wherein the portion of the alloy composition is provided in a layer having a thickness of less than 0.025 mm;
withdrawing the energy beam from the portion of the powdered alloy composition; and cooling the portion of the powdered alloy composition at a rate greater than or equal to 10 7 ° F. per second, thereby forming the oxide dispersion-strengthened alloy metal.
2. The method of claim 1 , wherein providing the oxide dispersion-strengthened alloy composition comprises providing a nickel chromium powder composition.
3. The method of claim 1 , wherein providing the oxide dispersion-strengthened alloy composition comprises providing a nickel aluminide powder composition.
4. The method of claim 1 , wherein providing the oxide dispersion-strengthened alloy composition comprises providing an iron aluminide or an iron-chromium-aluminium powder composition.
5. The method of claim 1 , wherein directing a low energy density energy beam at a portion of the powdered alloy composition comprises subjecting the powdered alloy composition to an additive manufacturing procedure that employs a low energy density laser beam.
6. The method of claim 5 , wherein subjecting the powdered alloy composition to the additive manufacturing procedure comprises subjecting the powdered alloy composition to a direct metal laser sintering procedure.
7. The method of claim 1 , wherein cooling the portion of the powdered alloy composition occurs immediately upon withdrawal of the energy beam.
8. The method of claim 7 , wherein cooling the portion of the powdered alloy composition occurs as a result of the withdrawal of the energy beam.
9. The method of claim 1 , further comprising directing the low energy density energy beam at a further portion of the alloy composition.
10. The method of claim 9 , further comprising withdrawing the energy beam from the further portion of the powdered alloy composition.
11. The method of claim 10 , further comprising cooling the further portion of the powdered alloy composition at a rate greater than or equal to 10 7 ° F. per second, thereby forming additional oxide dispersion-strengthened alloy metal.
12. The method of claim 11 , wherein the steps of directing the low energy density energy beam, withdrawing the energy beam, and cooling the portion of the powdered alloy composition are performed as a result of an additive manufacturing process applied to the powdered alloy composition.
13. The method of claim 12 , wherein the additive manufacturing process is direct metal laser sintering.
14. The method of claim 1 , wherein forming the oxide-dispersion strengthened alloy metal comprises forming a turbine engine component.
15. The method of claim 14 , wherein forming the turbine engine component comprises forming a turbine blade, a turbine vane, or a turbine nozzle.
16. The method of claim 1 , wherein providing the oxide-dispersion strengthened alloy in powdered form comprises providing a powder dispersion created by hydrometallurgical processing.
17. The method of claim 1 , wherein providing the oxide-dispersion strengthened alloy comprises providing an alloy having oxide dispersoids therein selected from the group consisting of: yttria, hafnia, silica, zirconia, and magnesia.
18. The method of claim 1 , wherein providing the oxide-dispersion strengthened alloy comprises providing a nickel or nickel chromium alloy having thorium oxide (ThO 2 ) dispersoids therein.