Arcuate seed casting method
A casting method includes forming a seed. The seed has a first end and a second end and an inner diameter (ID) surface and an outer diameter (OD) surface. The seed second end is placed in contact or spaced facing relation with a chill plate. The first end is contacted with molten material. The molten material is cooled and solidified so that a crystalline structure of the seed propagates into the solidifying material. At least a portion of the seed contacted with the molten material has a solidus higher than a solidus of at least an initial pour portion of the molten material.
1. A casting method comprising:
forming a seed, the seed having a first end and a second end and an inner diameter (ID) surface and an outer diameter (OD) surface;
placing the seed second end in contact or spaced facing relation with a chill plate;
contacting the first end with molten material; and
cooling and solidifying the molten material so that a crystalline structure of the seed propagates into the solidifying material,
wherein:
at least a portion of the seed contacted with the molten material has a solidus higher than a solidus of at least an initial pour portion of the molten material;
a subsequent pour portion of the molten material has a solidus higher than the solidus of the initial pour portion; and
after the solidifying, the initial pour portion and remainder of the seed are removed from the subsequent pour portion.
2. The method of claim 1 wherein:
the solidus of the initial pour portion is lower than a solution temperature of said portion of the seed.
3. The method of claim 2 wherein:
the solidus of the initial pour portion is at least 25° C. lower than the solution temperature of said portion of the seed.
4. The method of claim 3 wherein:
the solidus of said portion of the seed is at least 25° C. higher than the solidus of the initial pour portion.
5. The method of claim 1 wherein:
the solidus of said portion of the seed is at least 25° C. higher than the solidus of the initial pour portion.
6. The method of claim 1 wherein:
the solidus of said portion of the seed is 25° C. to 200° C. higher than the solidus of the initial pour portion.
7. The method of claim 1 wherein:
the seed and the molten material are nickel-based superalloys.
8. The method of claim 1 wherein:
the solidus of the subsequent pour portion of the molten material is 25° C. to 200° C. higher than the solidus of the initial pour portion.
9. The method of claim 1 wherein:
the molten material solidifies as a full annulus component.
10. The method of claim 1 wherein:
the seed is a single crystal seed.
11. The method of claim 10 wherein:
the forming comprises bending.
12. The method of claim 11 wherein:
the solidus of said portion of the seed is at least 25° C. higher than the solidus of the initial pour portion.
13. The method of claim 12 wherein:
the molten material solidifies as a full annulus component.
14. The method of claim 1 wherein:
the forming comprises bending.
15. The method of claim 14 wherein:
the solidus of said portion of the seed is at least 25° C. higher than the solidus of the initial pour portion.
16. The method of claim 15 wherein:
the removing essentially leaves only the second pour portion.
17. The method of claim 16 wherein:
the molten material solidifies as a full annulus component.