Thermal isolation for casting articles
Some embodiments provide methods and systems for casting articles. One example of a method includes providing and positioning a thermal blanket within a mold cavity and then introducing a molten material into the mold cavity and into contact with the thermal blanket. The method allows the molten material to remain in a molten state during a dwell time that extends from the introduction of the molten material at least until the mold cavity is filled. In another example, a method of using a thermal blanket includes keeping a molten material in a molten state during a dwell time extending from first introduction of the molten material until pressurization. Systems including a variety of mold types, one or more thermal blankets, and in some cases preforms and/or inserts are also provided. Also described is a novel thermal blanket and method of manufacturing the same.
1. A method for casting an article, comprising:
providing a thermal blanket apart from a mold cavity, the thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
after providing the thermal blanket apart from the mold cavity, then positioning at least a portion of the thermal blanket within the mold cavity; and
introducing a molten material into the mold cavity and into contact with the first surface of the thermal blanket until the molten material fills the mold cavity, wherein the molten material within the mold cavity remains in a molten state during a dwell time extending from the introducing of the molten material into the mold cavity at least until the molten material fills the mold cavity.
2. The method of claim 1 , wherein the second surface of the thermal blanket is adjacent at least a portion of an inner surface of the mold cavity.
3. The method of claim 1 , wherein the mold cavity comprises a first surface defined by at least a portion of a mold and wherein the second surface of the thermal blanket substantially covers the first surface of the mold cavity.
4. The method of claim 1 , further comprising positioning a porous preform and/or a non-porous insert within the mold cavity, wherein the thermal blanket isolates the molten material from at least part of the porous preform and/or at least part of the non-porous insert during the dwell time.
5. The method of claim 1 , wherein the molten material comprises at least one metal.
6. The method of claim 5 , wherein the at least one metal comprises aluminum, magnesium, and/or steel.
7. The method of claim 5 , wherein the molten material further comprises a particulate material.
8. The method of claim 1 , wherein the thermal blanket is a first thermal blanket, and further comprising providing a second thermal blanket, the second thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface, and further comprising positioning at least a portion of the second thermal blanket within the mold cavity.
9. A method for casting an article, comprising:
providing a first thermal blanket, the first thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
positioning at least a portion of the first thermal blanket within a mold cavity;
introducing a first molten material into the mold cavity and into contact with the first surface of the first thermal blanket;
providing a second thermal blanket, the second thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
positioning at least a portion of the second thermal blanket within the mold cavity;
positioning at least the portion of the second thermal blanket adjacent the first molten material and
introducing a second molten material into the mold cavity and into contact with the first surface of the second thermal blanket, wherein
the first and the second molten materials within the mold cavity remain in a molten state during a dwell time extending from the introducing of the first and the second molten materials into the mold cavity at least until the first and the second molten materials fill the mold cavity.
10. The method of claim 9 , wherein the first molten material and the second molten material are different.
11. A method for casting an article, comprising:
providing a thermal blanket apart from a mold cavity, the thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
after providing the thermal blanket apart from the mold cavity, then positioning at least a portion of the thermal blanket within the mold cavity;
introducing a molten material into the mold cavity and into contact with the first surface of the thermal blanket; and
applying pressure to the molten material until the molten material solidifies to form at least a portion of a cast article, wherein
the molten material within the mold cavity remains in a molten state during a dwell time extending from the introducing of the molten material into the mold cavity to the applying of pressure to the molten material.
12. The method of claim 11 , wherein the applying pressure comprises filling the mold cavity with the molten material and continuing to introduce the molten material into the mold cavity after filling the mold cavity.
13. The method of claim 11 , wherein the mold cavity is defined by at least a first mold portion and a second mold portion, and wherein the applying pressure comprises closing the first mold portion upon the second mold portion and upon the molten material within the mold cavity.
14. The method of claim 11 , wherein the molten material does not penetrate the first surface of the thermal blanket prior to applying the pressure to the molten material.
15. The method of claim 11 , wherein applying the pressure to the molten material causes the molten material to infiltrate the thermal blanket.
16. The method of claim 15 , wherein applying the pressure to the molten material breaks apart the thermal blanket.
17. The method of claim 15 , wherein applying the pressure to the molten material substantially disintegrates the thermal blanket.
18. The method of claim 11 , wherein the second surface of the thermal blanket is adjacent at least a portion of an inner surface of the mold cavity.
19. The method of claim 11 , wherein the mold cavity comprises a first surface defined by at least a portion of a mold and wherein the second surface of the thermal blanket substantially covers the first inner surface of the mold cavity.
20. The method of claim 11 , further comprising positioning a porous preform and/or non-porous insert within the mold cavity, wherein the thermal blanket isolates the molten material from at least part of the porous preform and/or at least part of the non-porous insert during the dwell time.
21. The method of claim 11 , wherein the molten material comprises at least one metal.
22. The method of claim 21 , wherein the at least one metal comprises aluminum and/or magnesium.
23. The method of claim 21 , wherein the molten material further comprises a particulate material.
24. The method of claim 11 , wherein the thermal blanket is a first thermal blanket, and further comprising providing a second thermal blanket, the second thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface, and further comprising positioning at least a portion of the second thermal blanket within the mold cavity.
25. A method for casting an article, comprising:
providing a first thermal blanket, the first thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
positioning at least a portion of the first thermal blanket within a mold cavity;
introducing a first molten material into the mold cavity and into contact with the first surface of the first thermal blanket;
providing a second thermal blanket, the second thermal blanket comprising a layer of thermally insulating material and having a first surface and a second surface;
positioning at least a portion of the second thermal blanket within the mold cavity;
positioning at least the portion of the second thermal blanket adjacent the first molten material;
introducing a second molten material into the mold cavity and into contact with the first surface of the second thermal blanket;
applying pressure to the first molten material and the second molten material until the first and the second molten materials solidify to form at least a portion of a cast article, wherein
the first and the second molten materials within the mold cavity remain in a molten state during a
dwell time extending from the introducing of the first and the second molten materials into the mold cavity to the applying of pressure to the first and the second molten materials.
26. The method of claim 25 , wherein the first molten material and the second molten material are different.