Induction processable ceramic die with durable die liner

• US 6,855,917 B2
• Filed: 12/06/2001
• Issued: 02/15/2005
• Est. Priority Date: 12/06/2001
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Fischer, John R., Matsen, Marc R., Kirkwood, Brad L., Brown, Ronald W.
• Primary Examiner(s): Hoang, Tu
• Application Number:
  US10/011,090
• Publication Number:
  US 20030106890A1
• Time in Patent Office: 1,167 Days
• Field of Search: 219/649, 219/659, 219/647, 219/603, 219/604, 219/615, 219/617, 219/633, 219/634, 219/635, 219/643, 148/520, 148/570, 148/571, 72/62, 723/429.6, 425/78
• US Class Current: 219/659
• CPC Class Codes: B29C 33/02 with incorporated heating or cooling means
• CPC Class Codes: B29C 33/3842 Manufacturing moulds, e.g. shaping the mould surface by machining
• CPC Class Codes: B29C 45/37 Mould cavity walls , i.e. the inner surface forming the mould cavity, e.g. linings
• CPC Class Codes: B29C 45/73 of the mould B29C45/2642 and B29C45/2737 take precedence

Abstract

A die liner for use in a die having a die body wherein the die body is configured to form a workpiece. The die liner is a discrete structure that is configured to be used in conjunction with the die body. The die liner defines a forming surface for forming the workpiece and is configured to have at least one characteristic that is different than a corresponding characteristic of the die body such that the die liner increases the durability of the die.

Claims

1. A die for use in a forming apparatus that uses inductive heating, the die comprising:

a die body having a cast portion that is formed from a first material;

a discrete liner coupled to the die body, the liner defining a die cavity and a forming surface, the liner being formed from a second material that is different from the first material, the second material also being a fiber-reinforced, sintered ceramic composite that is relatively more durable than the cast portion of the die body; and

wherein the fiber-reinforced, sintered ceramic composite comprises a plurality of continuous composite fibers.

2. The die of claim 1, wherein the fiber-reinforced, sintered ceramic composite is partially formed of a polymeric sol-gel.

3. The die of claim 2, wherein the polymeric sol-gel is selected from at least one of an organosilane and a glass ceramic sol.

4. The die of claim 3, wherein the fiber-reinforced, sintered ceramic composite further includes at least one silicon carbide fibers and aluminum oxide fibers.

5. The die of claim 1, wherein the liner is performed and the cast portion of the die body is cast onto a side of the liner opposite the forming surface.

6. The die of claim 4, wherein the liner is a composite that has been laid-up in a predetermined shape, cured and sintered.

7. The die of claim 1, wherein the composite includes a ceramic material selected from a group consisting of silicon carbide fibers and aluminum oxide fibers.

8. The die of claim 1, wherein the liner has a thickness of between about 2.0 mm and about 3.2 mm.

9. The die of claim 1, wherein the first material is selected from a group of materials consisting of phenolic and ceramic.

10. The die of claim 9, wherein the ceramic is castable fused silica.

11. The die of claim 1, further comprising a plurality of lateral and transverse reinforcing rods extending through the die body in separate planes.

12. The die of claim 11, wherein the reinforcing rods are formed of a material that is not susceptible to inductive heating or being electrically conductive and are arranged in a manner so as to not be susceptible to inductive heating.

13. The die of claim 11, wherein the reinforcing rods are tensioned to supply a compressive force that is exerted to the die body.

14. The die of claim 1, further comprising a plurality of induction coil segments imbedded within the die body.

15. The die of claim 14, wherein each of the coil segments is a copper tube and wherein the coil segments are cast into the die body adjacent the forming surface in a spaced arrangement to provide a substantially spatially uniform magnetic field across a workpiece when the coil segments are electrically connected together to form a coil and the coil is energized.

16. The die of claim 14, wherein the first and second materials are not susceptible to inductive heating.

17. A die liner for use in a die having a die body, the die liner being a discrete structure that is configured to be used in conjunction with the die body, the die liner defining a forming surface for forming the workpiece, the surface for forming the workpiece being made of a fiber-reinforced, sintered ceramic composite;

and

wherein the fiber-reinforced, sintered ceramic composite comprises a plurality of continuous composite fibers.

18. The die liner of claim 17, wherein the die liner is slip cast in a predetermined shape.

19. The die liner of claim 17, wherein the liner is a composite that has been laid-up in a predetermined shape, cured and sintered.

20. The die liner of claim 17, wherein the die liner has a thickness of about 2.0 mm to about 3.2 mm.

21. The die liner of claim 17, wherein the die liner is not susceptible to induction heating.

27. The die liner of claim 17, wherein the fiber-reinforced, sintered ceramic composite is partially formed of a polymeric sol-gel.

28. The die of claim 27, wherein the polymeric sol-gel is selected from at least one of an organosilane and a glass ceramic sol.

29. The die of claim 28, wherein the fiber-reinforced, sintered ceramic composite further includes at least one silicon carbide fibers and aluminum oxide fibers.

22. A method for forming a part at elevated temperature comprising the step of:

expanding a heated blank into contact with a forming surface in a die, the forming surface being made from a durable, inert, fiber-reinforced, sintered ceramic composite; and

wherein the durable, inert, fiber-reinforced, sintered ceramic composite comprises a plurality of continuous composite fibers.

23. The method of claim 22, wherein the durable, inert, fiber-reinforced, sintered ceramic composite forms a thin liner in the die that is backed with a castable ceramic.

24. The method of claim 23, further comprising the steps of:

heating the blank inductively to a forming temperature; and

expanding the blank at the forming temperature with a pressurized fluid.

25. The method of claim 23, further comprising the step of:

replacing the liner when worn while reusing the castable ceramic.

26. The method of claim 22, further comprising the steps of:

heating the blank inductively to a forming temperature; and

expanding the blank at the forming temperature with a pressurized fluid.