Powder metal mold casting for three dimensional parts

• US 7,578,335 B2
• Filed: 08/24/2004
• Issued: 08/25/2009
• Est. Priority Date: 08/24/2004
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Hetzner, James E., Rozario, Frederick J.
• Primary Examiner(s): Kerns; Kevin P
• Application Number:
  US10/924,498
• Publication Number:
  US 20060042769A1
• Time in Patent Office: 1,827 Days
• Field of Search: 164/4.1, 164/34, 164/35, 164/15, 164/529, 164/45
• US Class Current: 164/4.1
• CPC Class Codes: B22F 10/10 Formation of a green body
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/10 Sintering only
• CPC Class Codes: B22F 5/007 of moulds
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A process for powder metal mold casting of three-dimensional parts is disclosed wherein a casting of complex parts is facilitated.

Claims

1. A process for mold casting of a three-dimensional part comprising the steps of:

providing a computer data file representing a mold having a mold cavity formed therein for the three-dimensional part and a gating system in fluid communication with the mold cavity (18);

printing the mold from the computer data file in a plurality of layers with a mold forming material (22), wherein the mold having the mold cavity formed therein and the gating system are integrally formed by the mold forming material;

supplying a molten metal to the mold cavity of the mold through the gating system (28);

cooling the molten metal in the mold cavity to form a casting of the three-dimensional part; and

removing the mold from the casting (32).

2. The process according to claim 1, wherein the computer data file provided is a computer aided design file.

3. The process according to claim 1, further comprising the steps of providing a computer data file representing the three-dimensional part (12) and the gating system (14), and providing a computer data file representing a three-dimensional solid mold having a volume which is large enough to encompass the three-dimensional part and the gating system.

4. The process according to claim 3, further comprising the step of creating a computer data file by manipulating data in the computer data file representing the total volume of the three-dimensional part, the gating system, and data contained in the computer data file representing the solid mold (16) to result in the computer data file representing the mold (18).

5. The process according to claim 1, wherein the mold is removed from the casting by breaking away the mold (32).

6. The process according to claim 1, wherein the mold forming material is a powdered metal.

7. The process according to claim 6, wherein the mold forming material is stainless steel.

8. The process according to claim 1, further comprising the step of sintering the printed mold (26).

9. The process according to claim 1, further comprising the step of inverting the printed mold to remove loose excess mold forming material from the cavity of the mold (24).

10. A process for powdered metal mold casting of a three-dimensional part comprising the steps of:

a data preparation phase (10) comprising providing a computer data file representing a mold having a cavity formed therein for a three-dimensional part and a gating system in fluid communication with the cavity (18), wherein the mold having the mold cavity formed therein and the gating system are integrally formed by the mold forming material;

a molding and pouring phase (20) comprising printing the mold from the computer data file in a plurality of layers with the powdered metal (22), supplying a molten metal to the cavity of the mold through the gating system (28), and cooling the molten metal in the cavity to form a casting of the three-dimensional part; and

a knockout and finishing phase (30) comprising breaking away the powdered metal mold from the casting (32).

11. The process according to claim 10, wherein the computer data file provided is a computer aided design file.

12. The process according to claim 10, further comprising the steps of providing a computer data file representing the three-dimensional part and the gating system (14), and providing a computer data file representing a three-dimensional solid mold having a volume which is large enough to encompass the three-dimensional part and the gating system.

13. The process according to claim 12, further comprising the step of creating a computer data file by manipulating data in the computer data file representing the total volume of the three-dimensional part, the gating system, and data contained in the computer data file representing the solid mold (16) to result in the computer data file representing the mold (18).

14. The process according to claim 10, wherein the powdered metal is stainless steel.

15. The process according to claim 10, further comprising the step of sintering the printed mold (26).

16. A process for powdered metal mold casting of a three-dimensional part comprising the steps of:

providing a computer data file representing the three-dimensional part (12) and a gating system (14);

providing a computer data file representing a three-dimensional solid mold having a volume which is large enough to encompass the three-dimensional part and the gating system;

creating a computer data file by comparing and manipulating data in the computer data file representing the total volume of the three-dimensional part, the gating system, and data contained in the computer data file representing the solid mold (16) to result in a computer data file representing a mold having a mold cavity formed therein of the three-dimensional part and the gating system in fluid communication with the cavity (18);

printing the mold from the computer data file in a plurality of layers with a powdered metal (22), wherein the mold having the mold cavity formed therein and the gating system are integrally formed by the mold forming material;

supplying a molten metal to the mold cavity of the mold through the gating system (28);

cooling the molten metal in the mold cavity to form a casting of the three-dimensional part; and

breaking away the powdered metal mold from the casting (32).

17. The process according to claim 16, wherein the computer data files are computer aided design files.

18. The process according to claim 16, wherein the powdered metal is stainless steel.

19. The process according to claim 16, further comprising the step of sintering the printed mold (26).