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 region of the seating base.
1 - 19 . (canceled)
20 . A powder-metallurgical body, comprising:
a seating base formed in the body and a sealing element seated on the seating base so as to provide a seal with respect to liquids and/or gases;
said seating base having a depth region wherein said body is redensified in said depth region of said seating base.
21 . The body according to claim 20 , wherein the body is formed with a closed porosity in said depth region.
22 . The body according to claim 21 , wherein the body is formed exclusively with a closed porosity in said depth region.
23 . The body according to claim 20 , wherein said depth region is represented by a cross-sectional area formed as product of a material depth proceeding from said seating base and a material width extending substantially parallel to said seating base.
24 . The body according to claim 20 , wherein said depth region has a cross-sectional area of at least 0.3 mm 2 .
25 . The body according to claim 20 , wherein, given a material depth proceeding from said seating base of up to 0.05 mm, said depth region has a mean porosity of at most 4%.
26 . The body according to claim 25 , wherein said depth region has a mean porosity of no more than 2%.
27 . The body according to claim 20 , wherein, given a material depth proceeding from said seating base of up to 0.5 mm, said depth region has a mean porosity of at most 5%.
28 . The body according to claim 27 , wherein said depth region has a mean porosity of no more than 2.5%.
29 . The body according to claim 20 , wherein, given a material depth proceeding from said seating base of up to 1.0 mm, said depth region has a mean porosity of at most 6%.
30 . The body according to claim 29 , wherein said depth region has a mean porosity of no more than 3%.
31 . The body according to claim 20 , wherein, given a material depth proceeding from said seating base of up to 1.5 mm, said depth region has a mean porosity of at most 7%.
32 . The body according to claim 31 , wherein said depth region has a mean porosity of no more than 3.5%.
33 . The body according to claim 20 , wherein said seating base is a constituent part of a sealing groove for receiving said sealing element.
34 . The body according to claim 33 , wherein said seating base is a constituent part of a groove base of said sealing groove.
35 . The body according to claim 20 , wherein said seating base is formed continuously in a circumferential direction of the body.
36 . The body according to claim 33 , wherein said sealing groove is formed in a region of a front end of the body.
37 . A method of producing a powder-metallurgical body to be sealed by way of a sealing element, the method which comprises:
forming 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
seating the sealing element on the seating base.
38 . The method according to claim 37 , wherein the machining step comprises flattening the material elevation.
39 . The method according to claim 37 , wherein the machining step comprises machining the material elevation by calibration pressing.
40 . The method according to claim 37 , which comprises providing the body together with the seating base and the material elevation as a powder-metallurgical blank.
41 . The method according to claim 40 , which comprises sintering the powder-metallurgical blank and subsequently machining the material elevation.
42 . The method according to claim 37 , which comprise sealing pores on the surfaces of the body at least partially after the material elevation has been machined.
43 . The method according to claim 42 , which comprises sealing the pores by impregnation with a plastic.