BEARING COMPONENT

Abstract

A bearing component includes a black-oxide layer having metallic additional elements integrated in the structure of the black-oxide layer. Also a method of forming such a black-oxide layer that includes immersing the bearing component in a bath having the metallic additional element prior to immersing the bearing component in a black oxidation solution.

Claims

1. A bearing component that includes a black-oxide layer, wherein metallic additional elements are integrated in the structure of the black-oxide layer.

2. The bearing component according to claim 1, wherein the metallic additional elements are from 0.1 to 1 mass percent of the black-oxide layer.

3. The bearing component according to claim 1, wherein the metallic additional elements are from 0.3 to 0.7 mass percent of the black-oxide layer.

4. The bearing component according to claim 3 wherein the metallic additional elements include titanium.

5. The bearing component according to claim 1, wherein a concentration of the metallic additional elements integrated in the black-oxide layer decreases in a direction away from a surface of the black-oxide layer.

6. The bearing component according to claim 1, wherein the metallic additional elements are configured to change the properties of the black-oxide layer.

7. The bearing component according to claim 1, wherein the metallic additional elements include a metal oxide.

8. The bearing component according to claim 7, wherein the metal oxide comprises titanium oxide and/or titanium-iron oxide.

9. The bearing component according to claim 1, wherein the bearing component is a rolling-element bearing ring or a rolling element.

10. The bearing component according to claim 1, wherein metallic additional elements are integrated in a lattice structure of the black-oxide layer.

11. The bearing component according to claim 10, wherein the black oxide lattice structure has a cubic crystal symmetry and the metallic additional elements have a trigonal lattice structure.

12. The bearing component according to claim 11, wherein the metallic additional elements are from 0.3 to 0.7 mass percent of the black-oxide layer.

13. The bearing component according to claim 10, wherein the black oxide lattice structure has a first crystal symmetry and the metallic additional elements have a second crystal symmetry different than the first crystal symmetry.

14. The bearing component according to claim 10, wherein the black oxide layer includes magnetite and the metallic additional elements include titanium.

15. A method for manufacturing a bearing component comprising: a) depositing metallic additional elements on the bearing component, and b) immersing the bearing component, including the deposited metallic additional elements, in a black oxidation solution to form a black-oxide layer in which the metallic additional elements are integrated.

16. The method according to claim 15, wherein depositing the metallic additional comprises immersing the bearing component in a solution before immersing the bearing component in the black oxidation solution.

17. The method according to claim 16, wherein the solution comprises titanium dioxide.

18. The method according to claim 15, including repeating steps a and b.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0069] FIG. 1 is a schematic illustration of a method for manufacturing a bearing component according to the present disclosure.

DETAILED DESCRIPTION

[0070] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0071] FIG. 1 schematically shows a possible process of a method for manufacturing a bearing component 1 including a black-oxide layer 10. Here the bearing component 1 is depicted by way of example as a rolling-element bearing ring, but any other arbitrary bearing component, for example, a rolling-element, can be provided with such a black-oxide layer 10.

[0072] The bearing component 1 is first immersed in a pre-immersion solution 2 in which metallic additional elements are present. These metallic additional elements can be, for example, titanium dioxide that is present in a titanium dioxide suspension in the pre-immersion solution 2. Due to the immersion of the bearing component 1 in the pre-immersion solution 2, the metallic additional elements are deposited on the surface of the bearing component 1, as is depicted here by way of example by beads 4 at the surface of the bearing component.

[0073] The bearing component 1 is then transferred into a black oxidation bath 6. In this black oxidation bath 6 a transformation of the bearing component surface into a black-oxide layer 8 is effected. Here a releasing of iron and iron oxides that are contained in the material of the bearing component 1 and their continuous redepositing and restructuring occurs. Here the metallic additional elements 4 that are already deposited on the bearing component 1 are embedded in the black-oxide layer 8. In particular, the metallic additional elements are embedded in the structure of the black-oxide layer 8.

[0074] Here the pre-immersion and black oxidation in the pre-immersion solution 2 and the black oxidation can be repeated as often as desired, preferably two to three times. Furthermore, a quenching of the bearing component 1 can be effected after each black oxidation bath 6.

[0075] After conclusion of the black oxidation, a bearing component 1 is then present that includes a homogeneous alloyed black-oxide layer 10. The metallic additional elements 4 are embedded therein over the entire radial extension and not recognizable as separate elements. Only a possible additional-element excess could appear as a local concentration peak but without being functionally disadvantageous. The metallic additional elements 4 serve in particular to adapt the properties of the black-oxide layer 8 and do not contribute with their own properties.

[0076] Due to this alloyed black-oxide layer 10, it can be achieved in particular that the properties of a black-oxide layer are improved with respect to wear resistance and degree of wear.

[0077] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved bearing components having black oxide layers.

[0078] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0079] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0080] 1 Bearing component [0081] 2 Pre-immersion solution [0082] 3 Metallic additional elements [0083] 6 Black oxidation solution [0084] 8 Black-oxide layer [0085] 10 Alloyed black-oxide layer