Powder-metallurgical body and method for the production thereof
A powder-metallurgical body and a method for producing such a body. The powder-metallurgical body is formed with a seating base for seating a sealing element to produce a seal with respect to fluids, such as liquids and/or gases. The body is redensified in a low-lying depth region of the seating base.
1. A method of producing a powder-metallurgical body to be sealed by way of a sealing element, the method which comprises:
providing a seating base of the body for receiving and seating the sealing element, wherein the seating base has a material elevation;
machining the material elevation to cause the body to be redensified, after the machining, in a depth region of the seating base and to cause the depth region to have a lower mean porosity than a porosity of the body as a whole; and
seating the sealing element on the seating base after the material elevation has been machined.
2. The method according to claim 1 , wherein the machining step comprises flattening the material elevation.
3. The method according to claim 1 , wherein the machining step comprises machining the material elevation by calibration pressing.
4. The method according to claim 1 , which comprises providing the body together with the seating base and the material elevation as a powder-metallurgical blank.
5. The method according to claim 4 , which comprises sintering the powder-metallurgical blank and subsequently machining the material elevation.
6. The method according to claim 1 , which comprises sealing pores on the surfaces of the body at least partially after the material elevation has been machined.
7. The method according to claim 6 , which comprises sealing the pores by impregnation with a plastic.
8. The method according to claim 1 , which comprises forming the body with a closed porosity in the depth region.
9. The method according to claim 8 , which comprises forming the closed porosity exclusively in the depth region.
10. The method according to claim 1 , which comprises, given a material depth proceeding from the seating base of up to 0.05 mm, forming the depth region with a mean porosity of at most 4%.
11. The method according to claim 10 , which comprises forming the depth region with a mean porosity of no more than 2%.
12. The method according to claim 1 , which comprises, given a material depth proceeding from the seating base of up to 0.5 mm, forming the depth region with a mean porosity of at most 5%.
13. The method according to claim 12 , which comprises forming the depth region with a mean porosity of no more than 2.5%.
14. The method according to claim 1 , which comprises, given a material depth proceeding from the seating base of up to 1.0 mm, forming the depth region with a mean porosity of at most 6%.
15. The method according to claim 14 , which comprises forming the depth region with a mean porosity of no more than 3%.
16. The method according to claim 1 , which comprises, given a material depth proceeding from the seating base of up to 1.5 mm, forming the depth region with a mean porosity of at most 7%.
17. The method according to claim 16 , which comprises forming the depth region with a mean porosity of no more than 3.5%.
18. The method according to claim 1 , which comprises forming the seating base to extend continuously in a circumferential direction of the body.
19. The method according to claim 1 , which comprises forming the seating base as a constituent part of a sealing groove for receiving the sealing element.
20. The method according to claim 19 , which comprises forming the seating base as a constituent part of a groove base of the sealing groove.
21. The method according to claim 19 , which comprises forming the sealing groove in a region of a front end of the body.
22. The method according to claim 1 , which comprises seating the sealing element on the machined material elevation of the seating base.
23. A method of producing a powder-metallurgical body to be sealed by way of a sealing element, the method which comprises:
providing a seating base of the body for receiving and seating the sealing element with a material elevation;
machining the material elevation to cause the body to be redensified, after the machining, in a depth region of the seating base and to cause the depth region to have a lower mean porosity than a porosity of the body as a whole;
sealing pores on the surfaces of the body at least partially after the material elevation has been machined; and
seating the sealing element on the seating base.