US5380408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching process
Assignee: Sandvik Intellectual Property AB
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Filing: 1992-12-22
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Granted: 1995-01-10
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Expires: 2012-12-22
Abstract
Abstract The present invention relates to an etching process for the purpose of removing binder phase from the surface of a hard metal consisting of hard material in a binder phase based on cobalt and/or nickel. By carrying out the etching process electrolytically in a mixture containing concentrated sulfuric acid and concentrated phosphoric acid at a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C. an even binder phase removal without deep penetration is achieved.
Inventors
- 👤 Rolf Svensson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 02:21
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; Y; Y10; Y10S; Y10S427/00; Y10S427/103
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A method for removing a layer of binder phase formed on the surface of a hard material insert containing hard constituents in a binder phase based on cobalt and/or nickel, comprising removing said layer of binder phase formed on the surface of said insert by etching said insert electrolytically in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
Claim 2
Independent Claim
78 words
A method for removing a layer of binder phase formed on the surface of a hard material insert containing hard constituents in a binder phase based on cobalt and/or nickel, comprising removing said layer of binder phase formed on the surface of said insert by etching said insert electrolytically in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the surface of the hard material inserts is initially subjected to a mechanical treatment before the electrolytic etching step.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein said hard constituents comprise WC.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein said binder phase is cobalt.
Claim 6
Dependent Claim
30 words
The method of claim 1 wherein said mixture of concentrated sulfuric acid and concentrated phosphoric acid is in a volume ratio 0.75 to 1.25 with a water content of <25%.
Claim 7
Dependent Claim
30 words
The method of claim 5 wherein said mixture of concentrated sulfuric acid and concentrated phosphoric acid is in a volume ratio 0.95 to 1.05 with a water content of <15%.
Claim 8
Dependent Claim
30 words
The method of claim 1 wherein said surface further contains a graphite layer overlying said binder phase layer, said graphite layer being essentially removed prior to said electrolytic etching step.
Claim 9
Dependent Claim
30 words
The method of claim 1 wherein after said etching, a thin, wear-resistant layer of a metal carbide, oxide, nitride or mixtures thereof or diamond is deposited on said etched surface.
Claim 10
Independent Claim
94 words
A method for removing a layer of binder phase formed on the surface of a hard material insert, comprising removing a binder enriched layer formed on the surface of a hard material insert containing hard constituents in a binder phase based on cobalt and/or nickel, without removal of binder phase in channels between the hard material grains in said insert, by etching said inserts electrolytically in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
Claim 11
Independent Claim
94 words
A method for removing a layer of binder phase formed on the surface of a hard material insert, comprising removing a binder enriched layer formed on the surface of a hard material insert containing hard constituents in a binder phase based on cobalt and/or nickel, without removal of binder phase in channels between the hard material grains in said insert, by etching said inserts electrolytically in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
Claim 12
Independent Claim
95 words
A method of treating a hard material insert having a surface layer containing cobalt and/or nickel and a base layer containing hard constituents in a binder phase based on cobalt and/or nickel, comprising removing said surface layer of cobalt and/or nickel from said base layer without formation of pores by removal of binder phase between said hard constituents in said base layer by etching said insert in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
Claim 13
Independent Claim
95 words
A method of treating a hard material insert having a surface layer containing cobalt and/or nickel and a base layer containing hard constituents in a binder phase based on cobalt and/or nickel, comprising removing said surface layer of cobalt and/or nickel from said base layer without formation of pores by removal of binder phase between said hard constituents in said base layer by etching said insert in a mixture of concentrated sulfuric acid and concentrated phosphoric acid in a volume ratio of 0.5-2 with a water content of <50% at a temperature of 25°-60° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-09 | 1998-07-11 | 1999-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-09 | 2002-07-11 | 2003-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-09 | 2006-07-11 | 2007-01-10 | $7700.00 | Window Closed / Lapsed |