Turbine nozzles and methods of manufacturing the same
A turbine nozzle is provided and includes a first ring having a first microstructure, a vane extending from the first ring, a first porous zone between the first ring and the vane that is more porous than the first microstructure to attenuate thermo-mechanical fatigue cracking between the vane and the first ring. Methods of manufacturing the turbine nozzle are also provided.
1. A turbine nozzle, comprising:
a first ring having a first microstructure in at least a section thereof;
a vane extending from the first ring;
wherein one or both of the first ring and the vane have a first porous zone at the interface therebetween, the first porous zone being an extension of, and comprised of substantially identical material as a parent material of, one or both of the first ring and the vane, the first porous zone being more porous than the first microstructure to attenuate thermo-mechanical fatigue cracking between the vane and the first ring.
2. The turbine nozzle of claim 1 , wherein:
the first porous zone comprises a macroporous zone, wherein the macroporous zone comprises a predetermined lattice structure having an average percentage of a volume of voids over a total volume of material comprising the first porous zone in a range of about 10% to about 85%.
3. The turbine nozzle of claim 2 , wherein:
the macroporous zone comprises a honeycomb pattern.
4. The turbine nozzle of claim 2 , wherein:
the macroporous zone comprises a plurality of strands.
5. The turbine nozzle of claim 1 , wherein:
the first porous zone comprises a microporous microstructure, wherein the microporous microstructure has an average percentage of a volume of voids over the total volume of material comprising the first porous zone in a range of about 10% to about 85%.
6. The turbine nozzle of claim 1 , wherein:
the first microstructure comprises a fully densified microstructure; and
the first porous zone is more porous than the fully densified microstructure.
7. The turbine nozzle of claim 1 , further comprising:
a second ring having a second microstructure, the vane extending between the first ring and the second ring; and
a second porous zone that is more porous than the second microstructure to thereby attenuate thermo-mechanical fatigue cracking between the vane and the second ring.
8. A method of manufacturing a turbine component comprising:
performing an additive manufacturing process to form a portion of the turbine component having a first porosity zone and a second porosity zone, wherein the first porosity zone has a microstructure that is less porous than a microstructure of the second porosity zone, the portion of the turbine component having the second porosity zone being an extension of, and comprised of substantially identical material as a parent material of, the portion of the turbine component having the first porosity zone.
9. The method of claim 8 , wherein the first porosity zone comprises a fully densified microstructure, and the second porosity zone comprises a macroporous zone.
10. The method of claim 8 , wherein the first porosity zone comprises a fully densified microstructure, and the second porosity zone comprises a microporous microstructure.
11. The method of claim 10 , wherein the second porosity zone further comprises a macroporous zone.
12. The method of claim 8 , wherein the step of performing comprises:
defining a three-dimensional model of the turbine component; and
converting the three-dimensional model to a plurality of slices that each define a cross-sectional layer of the turbine component.
13. The method of claim 12 , wherein the performing step includes using a high energy density beam, the high energy density beam including at least one of a laser beam, an electron beam, a plasma jet, or an electric arc.
14. The method of claim 13 , wherein the step of performing includes one of sintering or melting a powdered metal to form the turbine component in successive layers.
15. The method of claim 8 , wherein the first porosity zone and the second porosity zone form a compliant joint.
16. The method of claim 15 , further comprising forming a braze layer over a surface of the turbine component for forming the compliant joint.
17. The method of claim 15 , further comprising forming an oxide layer over a surface of the turbine component for forming the compliant joint.
18. A turbine nozzle, comprising:
a first ring having a first microstructure;
a vane extending from the first ring; and
a first porous zone between the first ring and the vane that is more porous than the first microstructure to attenuate thermo-mechanical fatigue cracking between the vane and the first ring, wherein a braze layer is disposed over the first porous zone and between the first porous zone and the first ring.
19. The turbine nozzle of claim 18 , further comprising an oxide layer between the braze layer and the first porous zone.