EP0032887A1
Expired / Lapsed
EP
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Method of preparing coated cemented carbide product and resulting product
Assignee: Sandvik AB
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Filing: 1981-01-20
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Granted: —
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Expires: 2001-01-20
Abstract
Abstract An improved process for the production of coated cemented carbide products is disclosed. A cemented carbide substrate is treated to form a metal carbide, nitride or carbonitride coating. The coated substrate is heat-treated at a temperature close to the melting point of the binder metal of the cemented carbide to diffuse elements from the substrate into the coating. Thereafter, and without an intermediate oxidation of the coating, a wear-resistant oxide (e. g., aluminium oxide) coating is applied to form the improved coated cemented carbide product. In a modification of the process, an intermediate (second) metal carbide, nitride or carbonitride coating is applied after the heat treatment and a portion of the second coating is oxidized, nitrided or sulfided without detrimentally affecting the adherence of the second coating. In another modification of the process, a sulfur- and/ or nitrogen-containing gas is added during the last part of or subsequent to the first treatment of the cemented carbide substrate.
Inventors
- 👤 Gregor Henrik Kullander
- 👤 Christopher George Chatfield
- 👤 Marian Mikus
- 👤 Bo Kenneth Westergren
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 18:23
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/32; C23C16/34; C23C16/36; C23C16/40; C23C16/403; C23C30/00; C23C30/005
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
141 words
Method of treating a cemented carbide substrate containing at least one carbide together with binder metal in order to improve its wear resistance and utility, which method consists essentially of: (a) treating the substrate in an atmosphere selected from carbide, nitride and carbonitride forming atmospheres to form or apply a coating essentially comprising at least one coat of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. Si and B; (b) heat treating the coated substrate at a temperature close to or greater than the melting point of the binder phase in order to diffuse elements from the substrate into said coating or from the coating into the substrate; and (c) applying a wear resistant oxide coating on the thus pretreated cemented carbide substrate.
Claim 2
Dependent Claim
141 words
Method of treating a cemented carbide substrate containing at least one carbide together with binder metal in order to improve its wear resistance and utility, which method consists essentially of: (a) treating the substrate in an atmosphere selected from carbide, nitride and carbonitride forming atmospheres to form or apply a coating essentially comprising at least one coat of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. Si and B; (b) heat treating the coated substrate at a temperature close to or greater than the melting point of the binder phase in order to diffuse elements from the substrate into said coating or from the coating into the substrate; and (c) applying a wear resistant oxide coating on the thus pretreated cemented carbide substrate.
Claim 3
Dependent Claim
56 words
The method of claim 1, wherein a second coating of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Si and B is applied to the substrate treated according to the steps (a) + (b) prior to step (c).
Claim 4
Dependent Claim
42 words
The method of claim 2, wherein the resulting substrate is treated with an oxygen-, nitrogen- or sulfur-containing gas to oxidize, nitride or sulfide a portion of the second coating without detrimentally affecting the adherence of the second coating to the said substrate.
Claim 5
Dependent Claim
45 words
The method of claim 3, wherein a further coating of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Si and B is applied to the substrate treated.
Claim 6
Dependent Claim
24 words
The method of claim 4, wherein an'oxygen-, nitrogen- and/or sulfur-containing gas is added at the end of or at a period during the treatment.
Claim 7
Dependent Claim
36 words
The method of claim 1, wherein at least part of the binder metal which has diffused to the outermost part of the surface coating during the heat treatment step is removed by means of selective etchants.
Claim 8
Dependent Claim
53 words
The method of claim 1, wherein the treatment of the substrate according to the steps (a) + (b) is performed as one operation, in which the member of the metals of the substrate forming the carbide, nitride and carbonitride is brought to diffuse from the interior of the substrate out to the surface.
Claim 9
Dependent Claim
37 words
The method of claim 1, wherein a sulfur- and/or nitrogen-containing gas is added at the end of or at a period during the treatment of step (a) to form a sulfide and/or nitride portion on said coating.
Claim 10
Independent Claim
36 words
The method of any of the preceding claims, wherein the cemented carbide substrate is heat treated by a further step at a temperature close to or greater than the melting point of the binder metal phase.
Claim 11
Dependent Claim
8 words
The product of the process of claim 1.
References Cited (Backward Citations)
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