Single crystal engine valve

Patent metadata

Field	Value
Publication number	US-9644504-B2
Application number	US-201514660018-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Mar 17, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A valve for use in an internal combustion engine is disclosed. The valve includes a stem friction welded to a head portion. The head portion is cast from a single crystal metal using a casting process that creates little or no grain boundaries. The single crystal metal can be a nickel based superalloys such as CMSX-4, CMSX 3, Rene N5, and Rene N6. By having little or no grain boundaries, defects that occur in other types of casting material, such as large numbers of grain boundaries can be minimized. This allows the head portion and particularly the combustion face to withstand an operating temperature in the combustion chamber in excess of 850° C.

First claim

We claim:

1. An engine valve for use in an internal combustion engine, the engine valve comprising:
a stem having a first end and a second end;
a tip positioned at the first end of the stem; and
a head portion having a filet and a combustion face, the head portion being attached to the second end of the stem, wherein the head portion is cast from a single crystal metal, the single crystal metal having weight percentages of one of (a) 6.5% Cr, 9.0% Co, 0.6% Mo, 6.0% W, 6.5% Ta, 3% Re, 5.6% Al, 1.0% Ti, 0.10% Hf and the balance is nickel or other materials, (b) 8.0% Cr, 5.0% Co, 0.6% Mo, 8.0% W, 6.0% Ta, 5.6% Al, 1.0% Ti, 0.10% Hf and the balance is nickel or other materials, (c) 7.0% Cr, 7.5% Co, 1.5% Mo, 5.0% W, 6.5% Ta, 3% Re, 6.2% Al, 0.15% Hf and the balance is nickel or other materials, or (d) 4.2% Cr, 12.5% Co, 1.4% Mo, 6.0% W, 7.2% Ta, 5.4% Re, 5.8% Al, 0.15% Hf and the balance is nickel or other materials.

2. The valve of claim 1 , wherein the tip includes a wear resistance material.

3. The valve of claim 2 , wherein the wear resistant material is formed by hardened steel.

4. The valve of claim 2 , wherein the wear resistant material is attached to the stem by welding.

5. The valve of claim 1 , wherein the stem is made from a polycrystalline wrought steel.

6. The valve of claim 1 , wherein the stem is also cast using the single crystal metal and having no grain boundary.

7. An internal combustion engine, comprising:
a combustion chamber;
at least one air intake leading into the combustion chamber and defining a port configured to receive a valve, wherein the valve comprises:
a stem having a first end and a second end;
a tip positioned at the first end of the stem; and
a head portion having a filet and a combustion face, the head portion being attached to the second end of the stem, wherein the head portion is cast from a single crystal metal having a composition in weight percentage between 4.2 to 8% Cr, 5 to 12.5% Co, 0.6 to 1.5% Mo, 5 to 8% W, 6 to 7.5% Ta, 3 to 5.4% Re, 5.6 to 6.2% Al, 0 to 1.0% Ti, 0.10 to 0.15% Hf and the balance is nickel or other materials.

8. The engine of claim 7 , wherein the tip includes a wear resistance material.

9. The engine of claim 8 , wherein the wear resistant material is formed by hardened steel.

10. The engine of claim 8 , wherein the wear resistant material is attached to the stem by welding.

11. The engine of claim 7 , wherein the stem is made from a polycrystalline wrought steel.

12. The engine of claim 7 , wherein the stem is also cast using the single crystal metal.

13. The engine of claim 7 , wherein the single crystal metal having weight percentages of about 6.5% Cr, 9.0% Co, 0.6% Mo, 6.0% W, 6.5% Ta, 3% Re, 5.6% Al, 1.0% Ti, 0.10% Hf and the balance is nickel or other materials.

14. The engine of claim 7 , wherein the single crystal metal having weight percentages of about 8.0% Cr, 5.0% Co, 0.6% Mo, 8.0% W, 6.0% Ta, 5.6% Al, 1.0% Ti, 0.10% Hf and the balance is nickel or other materials.

15. The engine of claim 7 , wherein the single crystal metal having weight percentages of about 7.0% Cr, 7.5% Co, 1.5% Mo, 5.0% W, 6.5% Ta, 3% Re, 6.2% Al, 0.15% Hf and the balance is nickel or other materials.

16. The valve of claim 7 , wherein the single crystal metal having weight percentages of about 4.2% Cr, 12.5% Co, 1.4% Mo, 6.0% W, 7.2% Ta, 5.4% Re, 5.8% Al, 0.15% Hf and the balance is nickel or other materials.

17. An engine valve for use in an internal combustion engine, the engine valve comprising:
a stem having a first end and a second end;
a tip positioned at the first end of the stem; and
a head portion having a filet and a combustion face, the head portion being attached to the second end of the stem, wherein the head portion is cast from a single crystal metal, the single crystal metal being one of CMSX-4, CMSX-3, Rene N5, or Rene N6.

18. The engine valve of claim 17 , wherein the single crystal metal includes a composition in weight percentage of about 6.5% Cr, 9.0% Co, 0.6% Mo, 6.0% W, 6.5% Ta, 3% Re, 5.6% Al, 1.0% Ti, 0.10% Hf, and the balance is nickel or other materials.

19. The engine valve of claim 17 , wherein the single crystal metal includes a composition in weight percentage of about 8.0% Cr, 5.0% Co, 0.6% Mo, 8.0% W, 6.0% Ta, 5.6% Al, 1.0% Ti, 0.10% Hf and the balance is nickel or other materials.

20. The engine valve of claim 17 , wherein the single crystal metal includes a composition in weight percentage of about 7.0% Cr, 7.5% Co, 1.5% Mo, 5.0% W, 6.5% Ta, 3% Re, 6.2% Al, 0.15% Hf and the balance is nickel or other materials.

21. The engine valve of claim 17 , wherein the single crystal metal includes a composition in weight percentage of about 4.2% Cr, 12.5% Co, 1.4% Mo, 6.0% W, 7.2% Ta, 5.4% Re, 5.8% Al, 0.15% Hf and the balance is nickel or other materials.

Assignees

• Caterpillar Inc

Inventors

• Veliz Mark
• Geissler Mark

Classifications

• F01L2301/00

  Using particular materials · CPC title

• C22C19/057

  with the maximum Cr content being less 10% · CPC title

• F01L3/02 Primary

  Selecting particular materials for valve-members or valve-seats; Valve-members or valve-seats composed of two or more materials · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title

• B23K20/22

  taking account of the properties of the materials to be welded · CPC title