Method for machining materials by milling and subsequent brushing

1. A method for machining a material, comprising:

milling at a high cutting rate such that internal tensile stresses close to a surface which exceed a predetermined value may arise,

subsequent brushing to reduce the internal tensile stresses which exceed the predetermined value so as to be below the predetermined value, and

employing a brushing device in which brushes are present, such that brushing with the brushing device may be simultaneously carried out at a plurality of points.

2. The method as claimed in claim 1 ,

wherein grooves are milled into turbine shafts or into wheel disks.

3. The method as claimed in claim 1 ,

wherein brushing converts the internal tensile stresses into internal compressive stresses.

4. The method as claimed in claim 1 ,

wherein brushing is achieved by a translational and/or rotational movement.

5. The method as claimed in claim 1 ,

wherein the brushes are disposed on the brushing device such that a plurality of regions of a groove may be simultaneously brushed.

6. The method as claimed in claim 1 ,

wherein the brushes and bristles fastened thereon are optimized with respect to a desired reduction of the internal tensile stresses and to a desired service life of the brushing device,

wherein it is considered in the optimization that a reduction of the internal tensile stresses depends on a material of the bristles, a relative position of the bristles, a stiffness of the bristles, a speed of the bristles, a population density, and on internal tensile stresses which are present at a commencement of brushing.

7. The method as claimed in claim 1 ,

wherein the brushes comprise bristles that comprise one of the following: stainless steel, steel, nonferrous metals, plastic, plastic comprising embedded abrasive means, and natural bristles.

8. The method as claimed in claim 1 ,

wherein the brushes comprise bristles that comprise stainless-steel wire, a bristle diameter of 0.15 mm to 0.35 mm, and a tensile strength of 1500 N/mm 2 to 2400 N/mm 2 .

9. The method as claimed in claim 8 ,

wherein the bristles comprise a ratio of bristle length to bristle diameter of 30 to 500.

10. The method as claimed in claim 1 ,

wherein the milling takes place using high-speed steel cutting materials or carbide cutting materials.

11. The method as claimed in claim 1 ,

wherein the milling takes place at a milling feed rate of up to 38 mm/min.

12. A brushing device configured for carrying out a method according to claim 1 .

13. The brushing device as claimed in claim 12 ,

wherein the brushes comprise a contour adapted to grooves to be milled.

14. The method as claimed in claim 1 ,

wherein the material comprises steel.

15. The method as claimed in claim 2 ,

wherein the grooves comprise fir-tree grooves.

16. The method as claimed in claim 8 ,

wherein the tensile strength is 1800 N/mm 2 to 2100 N/mm 2 .

17. The method as claimed in claim 11 ,

wherein the milling feed rate is up to 13 mm/min.

18. A method for machining a material, comprising:

milling at a high cutting rate such that internal tensile stresses close to a surface which exceed a predetermined value may arise, and

subsequent brushing to reduce the internal tensile stresses which exceed the predetermined value to below the predetermined value,

wherein brushes comprising bristles comprising stainless-steel wire are employed, which bristles comprise a bristle diameter of 0.15 mm to 0.35 mm and a tensile strength of 1500 N/mm 2 to 2400 N/mm 2 .

19. A method for machining a material, comprising:

milling at a high cutting rate such that internal tensile stresses close to a surface which exceed a predetermined value may arise, and

subsequent brushing to reduce the internal tensile stresses which exceed the predetermined value to below the predetermined value,

wherein the milling takes place at a milling feed rate of up to 38 mm/min.