| 摘要 |
The invention relates to a surface-refined sintered alloy body comprising a hard phase, containing at least one compound selected from the group consisting of carbides, carbonitrides, carbooxides, carbonitrooxides of metals of groups 4a, 5a and 6a of the Periodic Table, and a binder phase which contains at least one metal of the iron group, and is characterised in that the relative concentration of the binder phase in the surface layer from 10 to 500 mu m from the surface of the sintered alloy is a maximum on the outermost surface and assumes an average concentration in the interior part and, in the direction of the interior part, is reduced until at least 5 mu m from the surface. The invention also relates to a process which is characterised in that in the aforesaid sintered alloy the relative concentration in the binder phase of the surface layer from 10 to 500 mu m from the surface of the sintered alloy is a maximum at the outermost surface and assumes an average concentration in the interior part, with a reduction of the concentration in the interior part taking place up to at least 5 mu m from the surface, by carrying out a decarbonisation treatment on the surface of the sintered alloy at a temperature within that region of the binder phase in which a solidus-liquidus region coexists, with this decarbonisation treatment being carried out after sintering or during sintering. |
