Multi-Shot Casting

• US 20170259330A1
• Filed: 05/25/2017
• Published: 09/14/2017
• Est. Priority Date: 12/14/2012
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Bullied, Steven J., Shah, Dilip M., Cetel, Alan D., Marcin, John J.
• Granted Patent: US 10,456,830 B2
• Time in Patent Office: Days
• CPC Class Codes: B22D 19/16 for making compound objects cast of two or more different metals, e.g. for making rolls for rolling mills casting compound ingots B22D7/02
• CPC Class Codes: B22D 27/045 Directionally solidified castings
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F05D 2230/211 by precision casting, e.g. microfusing or investment casting

Abstract

An alloy part is cast in a mold (280) having a part-forming cavity (292, 294, 296). The method comprises pouring a first alloy into the mold. The pouring causes: a surface (550) of the first alloy in the part-forming cavity to raise relative to the part-forming cavity; a branch flow of the poured first alloy to pass upwardly through a first portion (304) of a passageway; and the branch flow to pass downwardly through a second portion (310), of the passageway; solidifying some of the first alloy in the passageway to block the passageway while at least some of the first alloy in the part-forming cavity remains molten. A second alloy is poured into the mold atop the first alloy and solidified.

Claims

1. A casting mold (280;

398) comprising;

a part-forming cavity (292, 294, 296) having a lower end and an upper end; and

at least one overflow passageway (302, 304, 310;

302-2;

304-2;

310-2) having an apex (314;

314-2) at a level between the upper end and the lower end.

2. The casting mold of claim 1 wherein the part is a blade and the part-forming cavity comprises:

a root portion for casting an attachment root of the blade; and

an airfoil section for casting an airfoil of the blade, the airfoil having a first end and a second end and a span between the first end and the second end.

3. The casting mold of claim 2 wherein:

the apex (550;

550-2) is at a level along the span.

4. The casting mold of claim 1 further comprising a grain starter (298) below the part-forming cavity.

5. The casting mold of claim 1 wherein the overflow passageway comprises an up-pass (304;

304-2) from the part-forming cavity to the apex and a downpass (310;

310-2) from the apex and including an enlarged chamber (302;

302-2).

6. The casting mold of claim 1 further comprising:

a pour cone (406); and

a downsprue extending from the pour cone toward the part-forming cavity and comprising;

a lower portion (402) having a plurality of ports (422, 428) in communication with the part-forming cavity; and

an upper portion (404) telescoping relative to the lower portion and coupling the lower portion to the pour cone.

7. The casting mold of claim 1 further comprising:

a first pour cone (602);

a downsprue (606, 360) extending from the first pour cone toward the part-forming cavity; and

a second pour cone (604) in communication with the part-forming cavity.

8. The casting mold of claim 1 in combination with a casting apparatus, the casting apparatus having:

a first ingot feeder (804);

a first induction melter (808) positioned to receive an ingot from the first ingot feeder;

a first actuator (809) for rotating the first induction melter from a charging orientation to a pouring orientation for pouring into the part-forming cavity;

a second ingot feeder (804);

a second induction melter (808) positioned to receive an ingot from the second ingot feeder; and

a second actuator (809) for rotating the second induction melter from a charging orientation to a pouring orientation for pouring into the part-forming cavity.

9. A casting mold comprising:

a part-forming cavity (296) having a lower end and an upper end (406);

a pour cone; and

a downsprue extending from the pour cone toward the part-forming cavity and comprising;

a lower portion (402) having a plurality of ports in communication with the part-forming cavity; and

an upper portion telescoping (404) relative to the lower portion and coupling the lower portion to the pour cone.

10. The casting mold of claim 9 wherein:

the mold along the part-forming cavity and the lower portion are formed as a single piece.

11. The casting mold of claim 9 wherein:

the part-forming cavity is one of a plurality of part-forming cavities;

each of the plurality of part-forming cavities coupled to a single said downsprue.

12. A method for using the casting mold of claim 9, the method comprising:

introducing a molten alloy to the part-forming cavity through the pour cone and a lower port of the plurality of ports;

extending the upper portion relative to the lower portion; and

introducing a molten alloy to the part-forming cavity through the pour cone and an upper port of the plurality of ports.

13. The method of claim 12 wherein one or more of:

the molten alloy introduced through the upper port is different from the molten alloy introduced through the lower port;

the molten alloy introduced through the upper port is introduced after a partial solidification of the molten alloy introduced through the lower port; and

the molten alloy introduced through the upper port is introduced from a second ingot and the molten alloy introduced through the lower port is introduced from a first ingot.

14. A method for casting with a mold (600) having a plurality of part cavities, the method comprising:

a first pour through a first pour cone (602), the first pour filling a lower portion of each of the part cavities; and

a second pour through a second pour cone (604), the second pour filling an upper portion of each of the part cavities.

15. The method of claim 14 wherein:

the first pour cone is concentric with the second pour cone.

16. The method of claim 14 wherein:

the first pour is a bottom feed and the second pour is a top feed.