Self lubricating titanium aluminide composite material

Patent metadata

Field	Value
Publication number	US-11619266-B2
Application number	US-201916282727-A
Country	US
Kind code	B2
Filing date	Feb 22, 2019
Priority date	Feb 26, 2018
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A composite material having an alloy matrix including titanium, aluminum, niobium, manganese, boron, and carbon is disclosed. The composite material includes, by atomic percentage, 40.0% to 50.0% Al, 1.0% to 8.0% Nb, 0.5% to 2.0% Mn, 0.1% to 2.0% B, and 0.01% to 0.2% C. The composite material is doped with a solid lubricant such as MoS2, ZnO, CuO, hexagonal boron nitride (hBN), WS2, AgTaO3, CuTaO3, CuTa2O6, or combinations thereof. Components composed of the composite material exhibit increased ductility at room temperature and reduced fracture tendency, resulting in improved durability.

First claim

What is claimed is:

1. A composite material comprising:
a titanium aluminide alloy matrix including titanium, aluminum, niobium, manganese, boron, and carbon; and
a solid lubricant,
wherein the alloy matrix has a two-phase, fully lamellar microstructure, with the solid lubricant being dispersed therein;

wherein the composite material comprises, by atomic percentage, 40.0% to 50.0% Al, 1.0% to 8.0% Nb, 0.5% to 2.0% Mn, 0.1% to 2.0% B, and 0.01% to 0.2% C;
wherein the solid lubricant is present in the alloy matrix at an atomic percentage of 1% to 30% of the composite material.

2. The composite material according to claim 1 , wherein the solid lubricant consists of hexagonal boron nitride (hBN).

3. The composite material according to claim 1 , wherein the solid lubricant is substantially homogenously distributed as discrete, inert particles.

4. The composite material according to claim 1 , wherein the lamella have a maximum thickness of 1 μm.

5. The composite material according to claim 1 , wherein the titanium, aluminum, niobium, manganese, boron, and carbon are uniformly distributed throughout the alloy matrix.

6. The composite material according to claim 1 , wherein the composite material has a room temperature percent elongation of a minimum of 0.5%.

7. The composite material according to claim 1 , wherein the composite material has a coefficient of friction less than 0.065 from room temperature up to 800° C.

8. The composite material according to claim 1 , wherein the composite material has a wear rate less than 4.5×10 −4 mm 3 ·N −1 ·m −1 , from room temperature up to 800° C.

9. A bearing comprising:
an outer member; and
an inner member in sliding engagement with the outer member;
wherein at least one of the inner member and the outer member consists of the fully lamellar composite material according to claim 1 .

10. The composite material of claim 1 , wherein the solid lubricant consists of MoS 2 .

11. The composite material of claim 1 , wherein the solid lubricant consists of ZnO.

12. The composite material of claim 1 , wherein the solid lubricant consists of CuO.

13. The composite material of claim 1 , wherein the solid lubricant consists of WS 2 .

14. The composite material of claim 1 , wherein the solid lubricant consists of AgTaO 3 .

15. The composite material of claim 1 , wherein the solid lubricant consists of CuTaO 3 .

16. The composite material of claim 1 , wherein the solid lubricant consists of CuTa 2 O 6 .

17. A composite material comprising:
a titanium aluminide alloy matrix including titanium, aluminum, niobium, manganese, boron, and carbon; and
a solid lubricant,
wherein the alloy matrix has a two-phase, near-fully lamellar microstructure, with the solid lubricant being dispersed therein;
wherein the composite material comprises, by atomic percentage, 40.0% to 50.0% Al, 1.0% to 8.0% Nb, 0.5% to 2.0% Mn, 0.1% to 2.0% B, and 0.01% to 0.2% C;
wherein the solid lubricant is present in the alloy matrix at an atomic percent of 1% to 30% of the composite material.

18. The composite material according to claim 17 , wherein the solid lubricant consists of hexagonal boron nitride (hBN).

19. The composite material according to claim 17 , wherein the solid lubricant is substantially homogenously distributed as discrete, inert particles.

20. The composite material according to claim 17 , wherein the lamella have a maximum thickness of 1 μm.

21. The composite material according to claim 17 , wherein the titanium, aluminum, niobium, manganese, boron, and carbon are uniformly distributed throughout the alloy matrix.

22. The composite material according to claim 17 , wherein the composite material has a room temperature percent elongation of a minimum of 0.5%.

23. The composite material according to claim 17 , wherein the composite material has a coefficient of friction less than 0.065 from room temperature up to 800° C.

24. The composite material according to claim 17 , wherein the composite material has a wear rate less than 4.5×10 −4 mm 3 ·N −1 ·m −1 , from room temperature up to 800° C.

25. The composite material of claim 17 , wherein the solid lubricant consists of MoS 2 .

26. The composite material of claim 17 , wherein the solid lubricant consists of ZnO.

27. The composite material of claim 17 , wherein the solid lubricant consists of CuO.

28. The composite material of claim 17 , wherein the solid lubricant consists of WS 2 .

29. The composite material of claim 17 , wherein the solid lubricant consists of AgTaO 3 .

30. The composite material of claim 17 , wherein the solid lubricant consists of CuTaO 3 .

31. The composite material of claim 17 , wherein the solid lubricant consists of CuTa 2 O 6 .

32. A bearing comprising:
an outer member; and
an inner member in sliding engagement with the outer member;
wherein at least one of the inner member and the outer member consists of the near-fully lamellar composite material according to claim 17 .

33. The composite material of claim 1 , wherein impurities are trapped within α 2 layers of the microstructure.

34. The composite material of claim 33 , wherein the impurities are associated with a powder metallurgical process used to make the composite material.

35. The composite material of claim 33 , wherein the impurities comprise either one or both of carbon and oxygen.

36. The composite material of claim 1 , wherein grain boundaries of the composite material are refined by precipitation of TiB 2 at the grain boundaries.

37. The composite material of claim 1 , wherein
the alloy matrix is composed of α 2 layers and γ layers,
the α 2 layers are composed substantially of Ti 3 Al,
the γ layers are composed substantially of TiAl, and
the α 2 layers and the γ layers have a maximum thickness of 0.1 μm to 1 μm.

Assignees

• Roller Bearing Co America Inc

Inventors

• Adams Frank C
• Heuberger Mark
• Smith Charles E
• Boyan Patrick S
• Robinson Ernest K

Classifications

• F16C33/121

  Use of special materials · CPC title

• F16C33/1095

  with solids as lubricant, e.g. dry coatings, powder · CPC title

• C22C30/00

  Alloys containing less than 50% by weight of each constituent · CPC title

• F16C23/045

  for radial load mainly, e.g. radial spherical plain bearings · CPC title

• C22C14/00 Primary

  Alloys based on titanium · CPC title