US20040011431A1 - Passivation method - Google Patents

Passivation method Download PDF

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Publication number
US20040011431A1
US20040011431A1 US10/416,087 US41608703A US2004011431A1 US 20040011431 A1 US20040011431 A1 US 20040011431A1 US 41608703 A US41608703 A US 41608703A US 2004011431 A1 US2004011431 A1 US 2004011431A1
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United States
Prior art keywords
passivation
chrome
zinc
layer
passivated layer
Prior art date
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Abandoned
Application number
US10/416,087
Inventor
Ernst-Walter Hillebrand
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Hillebrand Walter GmbH and Co KG
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Hillebrand Walter GmbH and Co KG
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Assigned to WALTER HILLEBRAND GMBH & CO. GALVANOTECHNIK reassignment WALTER HILLEBRAND GMBH & CO. GALVANOTECHNIK ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HILLEBRAND, ERNST-WALTER
Publication of US20040011431A1 publication Critical patent/US20040011431A1/en
Abandoned legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
    • C23C22/53—Treatment of zinc or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/46—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing oxalates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
    • C23C2222/10—Use of solutions containing trivalent chromium but free of hexavalent chromium

Definitions

  • the invention refers to a method to passivate zinc and zinc alloy layers as well as cadmium and cadmium alloy layers and claims the priority of German patent application 100 55 215.3, which is referred to for purpose of disclosure.
  • chrome(VI) compounds contrasts their good anticorrosive qualities. Accordingly, it has been attempted for a longer period time to establish chrome(VI) free systems providing a sufficient corrosion resistance.
  • the invention has the object to provide both a passivation method with further improved anticorrosive protection characteristics and a respective coating system.
  • the invention is based on the finding, that turning away from the efforts of focussing on a compact conversion layer and thus aiming to produce a porous conversion layer leads to improved final products when the porosity is used for binding to at least one further layer.
  • the invention can be realized by using cobalt in a passivation solution containing chrome(III) and a weaker complexing agent—preferably a di- or tri-carbonic acid like oxalic acid.
  • cobalt concentration greater than 30 ⁇ l, preferably a concentration between 70 g/l and 100 g/l, In particular about 90 g/l, (concentrate—12%) already surprising corrosion protection values of 240 h until onset of primary corrosion according to DIN 50961 in the salt spray test according to DIN 50021 SS are achieved in production.
  • the method Is preferably carried out at temperatures up to 55° C. and pH levels of 0,5 to 5,5.
  • the passivation is carried out at pH 4.
  • Particularly good results can be achieved with a sulfate free solution. This is based on the idea that the use of sulfate leads to a disturbance of the catalytic reaction and interference with the development of an anticorrosive chrome layer.
  • the passivated layer is re-treated with an organic or inorganic coating which penetrates into the porous conversion layer.
  • an organic or inorganic coating which penetrates into the porous conversion layer.
  • a coat of AquaresTM (Enthone-OMI GmbH, Neuss) is applied to the passivation layer.
  • a particularly good corrosion control can be achieved by a double Aquares layer.
  • the Aquares layer surprisingly is no longer traceable in the REM in some variants of the invention.
  • this dry lubricant layer is applied onto a double Aquares layer.

Abstract

The invention refers to a method for the passivation of zinc, cadmium or their alloys, in particular of zinc-nickel alloys by means of a chrome(VI) free solution containing a weak complexing agent, preferably di- or tri-carbonic acids, preferably chrome(III)-oxalate complex and Co2+, whereby the concentration of Co2+ is greater than 30 g/l.

Description

  • The invention refers to a method to passivate zinc and zinc alloy layers as well as cadmium and cadmium alloy layers and claims the priority of German patent application 100 55 215.3, which is referred to for purpose of disclosure. [0001]
  • It is known to galvanically coat metallic surfaces with metals or metal alloys in order to improve corrosion resistance. Moreover, it is known to further increase the anticorrosive effect of this layer both by its modification and by additional coating systems. A system with good anticorrosive effect is represented by a galvanically applied zinc-nickel alloy, which Is subsequently chromatized and which can additionally be treated with an organic or inorganic coat. A good corrosion resistance is achieved by employing chrome(VI) for passivating the zinc-nickel layer. [0002]
  • The toxicity of chrome(VI) compounds contrasts their good anticorrosive qualities. Accordingly, it has been attempted for a longer period time to establish chrome(VI) free systems providing a sufficient corrosion resistance. [0003]
  • For this goal it is known to use chrome(III)-containing passivation solutions as described in the U.S. Pat. No. 4,171,231, which however—due the oxidants also present in the solution—do not lead to chrome(VI) free passivation layers, since chrome(III) is oxidized during the treatment. [0004]
  • The DE 41 35 524 C2, which is Incorporated into the present description and the teaching of which is fully referred to discloses a passivation method, which achieves Improved anti-corrosion values by a chrome(III)-containing passivation solution with an oxalate complexation (Tab. II; Tab, III). Different examples of chrome(III) compounds for passivation are given In table IV of the mentioned document. The good anticorrosive effect of the passivation method described in this document is based on the use of oxalate as a complexing agent, which—in contrast to other complexing agents—supports the incorporation of chrome into the passivation layer. [0005]
  • With this type of passivation method one can already achieve good anticorrosion results. Moreover, it Is known to Increase the anticorrosive protection provided by chrome(III)-based passivation methods by the use of cobalt. [0006]
  • The improvement of anticorrosive protection by the use of cobalt is described in the WO 97/40208, which is hereby incorporated. [0007]
  • As it can also be seen from this document, the experts aim to produce a conversion layer as compact as possible in order to achieve the layers desired qualities with respect to resistance to corrosion and chemicals. [0008]
  • The invention has the object to provide both a passivation method with further improved anticorrosive protection characteristics and a respective coating system.[0009]
  • This aim is achieved by a method and a passivation solution according to the independent claims, Favorable aspects are subject of the dependent claims. [0010]
  • The invention is based on the finding, that turning away from the efforts of focussing on a compact conversion layer and thus aiming to produce a porous conversion layer leads to improved final products when the porosity is used for binding to at least one further layer. [0011]
  • The invention can be realized by using cobalt in a passivation solution containing chrome(III) and a weaker complexing agent—preferably a di- or tri-carbonic acid like oxalic acid. [0012]
  • By using a cobalt concentration greater than 30 μl, preferably a concentration between 70 g/l and 100 g/l, In particular about 90 g/l, (concentrate—12%) already surprising corrosion protection values of 240 h until onset of primary corrosion according to DIN 50961 in the salt spray test according to DIN 50021 SS are achieved in production. Favorably the chrome-cobalt-ratio is 1,7:2,0=0,85. [0013]
  • The method Is preferably carried out at temperatures up to 55° C. and pH levels of 0,5 to 5,5. Preferably the passivation is carried out at pH 4. Particularly good results can be achieved with a sulfate free solution. This is based on the idea that the use of sulfate leads to a disturbance of the catalytic reaction and interference with the development of an anticorrosive chrome layer. [0014]
  • The passivated layer is re-treated with an organic or inorganic coating which penetrates into the porous conversion layer. Preferably, a coat of Aquares™ (Enthone-OMI GmbH, Neuss) is applied to the passivation layer. A particularly good corrosion control can be achieved by a double Aquares layer. The Aquares layer surprisingly is no longer traceable in the REM in some variants of the invention. [0015]
  • Both the characteristics of corrosion control and resistance to chemicals can be further improved by means of a Topcoat containing a dry lubricant. Also this coat according to the invention engages in a special binding to the porous conversion layer. Hereby, the desired friction and flow values can achieved at the same time. [0016]
  • Surprising properties are displayed by a combination of the dry lubricant Molykote® D-7100 (Dow Corning) and the zinc-nickel alloy passivated according to the invention. In comparison to known coating systems this system is particularly resistant to chemicals and rim cleaner. It is thus especially suitable for wheel screws. Furthermore a surprising temperature insensitivity of the combination according to the invention has been stated. [0017]
  • Preferably this dry lubricant layer is applied onto a double Aquares layer. [0018]

Claims (15)

1. Method for the passivation of zinc, cadmium or their alloys, in particular of zinc-nickel alloys by means of a chrome(VI) free solution containing a weak complexing agent preferably di- or tri-carbonic acids, preferably chrome(III)-oxalate complex and Co2+, characterized in that the Co2+ concentration is greater than 30 g/l.
2. Method according to claim 1, characterized in that the Co2+ concentration is 70 to 110 g/l.
3. Method according to claim 1, characterized in that the Co2+ concentration is about 90 g/l.
4. Method according to one of the preceding claims, characterized in that the passivation is carried out at 20° C. to 55° C.
5. Method according to one of the preceding claims, characterized in that the passivation is carried out at pH 0,5 to 5,5.
6. Method according to one of the preceding claims, characterized in that the passivation is carried out at pH 4.
7. Method according to one of the preceding claims, characterized in that the ratio of chrome to cobalt is 1,7: 2,0.
8. Method according to one of the preceding claims, characterized in that the solution is sulfate free.
9. Method according to one of the preceding claims, characterized in that the passivated layer is treated by an additional coating.
10. Method according to one of the preceding claims characterized by a coating with Aquares™.
11. Method according to one of the preceding claims, characterized by a double coating with Aquares™.
12. Method according to one of the preceding claims, characterized in that the passivated layer is treated with a dry lubricant.
13. Method according to one of the preceding claims, characterized in that the passivated layer is coated with an organic Topcoat.
14. Method according to one of the preceding claims, characterized in that the passivated layer is treated with a PTFE-containing coat.
15. Method according to the preceding claim, characterized in that the passivated layer is coated with Molykote® D 7100.
US10/416,087 2000-11-07 2001-11-07 Passivation method Abandoned US20040011431A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10055215.3 2000-11-07
DE10055215A DE10055215A1 (en) 2000-11-07 2000-11-07 passivation
PCT/EP2001/012866 WO2002038829A1 (en) 2000-11-07 2001-11-07 Passivation method

Publications (1)

Publication Number Publication Date
US20040011431A1 true US20040011431A1 (en) 2004-01-22

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US10/416,087 Abandoned US20040011431A1 (en) 2000-11-07 2001-11-07 Passivation method

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US (1) US20040011431A1 (en)
EP (1) EP1346081A1 (en)
JP (1) JP2004513240A (en)
CN (1) CN1478155A (en)
AU (1) AU2002221819A1 (en)
BR (1) BR0115161A (en)
CA (1) CA2428138A1 (en)
CZ (1) CZ20031237A3 (en)
DE (1) DE10055215A1 (en)
MX (1) MXPA03004019A (en)
SK (1) SK5442003A3 (en)
WO (1) WO2002038829A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070004222A1 (en) * 2005-06-29 2007-01-04 Qingqiao Wei Fabrication of aligned nanowire lattices
US20090194001A1 (en) * 2006-07-10 2009-08-06 Nippon Chemical Industrial Co., Ltd. Organic acid chromium (iii) salt aqueous solution and process of producing the same
US20180138406A1 (en) * 2004-12-30 2018-05-17 Micron Technology, Inc. Dual resistive-material regions for phase change memory devices

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3332373B1 (en) † 2001-11-30 2002-10-07 ディップソール株式会社 A treatment solution for forming a hexavalent chromium-free rust preventive film on zinc and zinc alloy plating, a hexavalent chromium-free rust preventive film, and a method for forming the same.
CN1307323C (en) * 2004-06-14 2007-03-28 广州市集胜化工有限公司 Trivalent chromic rainbow color passivating agent for galvanizing and its production
DE102016005656A1 (en) 2016-05-11 2017-11-16 Surtec International Gmbh Conversion layers for metallic surfaces

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4349392A (en) * 1981-05-20 1982-09-14 Occidental Chemical Corporation Trivalent chromium passivate solution and process
US4359345A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Trivalent chromium passivate solution and process
US4359347A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Chromium-free passivate solution and process
US4359348A (en) * 1981-06-17 1982-11-16 Occidental Chemical Corporation Stabilized trivalent chromium passivate composition and process
US4359346A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Trivalent chromium passivate solution and process for yellow passivate film
US4367099A (en) * 1981-06-15 1983-01-04 Occidental Chemical Corporation Trivalent chromium passivate process
US4384902A (en) * 1981-06-15 1983-05-24 Occidental Chemical Corporation Trivalent chromium passivate composition and process
US4971635A (en) * 1987-02-06 1990-11-20 Guhde Donald J Low-cure coating composition
USRE34707E (en) * 1986-06-13 1994-08-30 Dacral S.A. Anticorrosion coating composition with improved stability, and coated substrate
US5368655A (en) * 1992-10-23 1994-11-29 Alchem Corp. Process for chromating surfaces of zinc, cadmium and alloys thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1228000A (en) * 1981-04-16 1987-10-13 David E. Crotty Chromium appearance passivate solution and process
DE19905134A1 (en) * 1999-02-09 2000-09-28 Hillebrand Walter Gmbh & Co Kg Passivation process

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4359345A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Trivalent chromium passivate solution and process
US4359347A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Chromium-free passivate solution and process
US4359346A (en) * 1981-04-16 1982-11-16 Occidental Chemical Corporation Trivalent chromium passivate solution and process for yellow passivate film
US4349392A (en) * 1981-05-20 1982-09-14 Occidental Chemical Corporation Trivalent chromium passivate solution and process
US4367099A (en) * 1981-06-15 1983-01-04 Occidental Chemical Corporation Trivalent chromium passivate process
US4384902A (en) * 1981-06-15 1983-05-24 Occidental Chemical Corporation Trivalent chromium passivate composition and process
US4359348A (en) * 1981-06-17 1982-11-16 Occidental Chemical Corporation Stabilized trivalent chromium passivate composition and process
USRE34707E (en) * 1986-06-13 1994-08-30 Dacral S.A. Anticorrosion coating composition with improved stability, and coated substrate
US4971635A (en) * 1987-02-06 1990-11-20 Guhde Donald J Low-cure coating composition
US5368655A (en) * 1992-10-23 1994-11-29 Alchem Corp. Process for chromating surfaces of zinc, cadmium and alloys thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180138406A1 (en) * 2004-12-30 2018-05-17 Micron Technology, Inc. Dual resistive-material regions for phase change memory devices
US20070004222A1 (en) * 2005-06-29 2007-01-04 Qingqiao Wei Fabrication of aligned nanowire lattices
US20080009121A1 (en) * 2005-06-29 2008-01-10 Qingqiao Wei Fabrication of Aligned Nanowire Lattices
US20090194001A1 (en) * 2006-07-10 2009-08-06 Nippon Chemical Industrial Co., Ltd. Organic acid chromium (iii) salt aqueous solution and process of producing the same

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Publication number Publication date
AU2002221819A1 (en) 2002-05-21
CA2428138A1 (en) 2002-05-16
SK5442003A3 (en) 2003-10-07
BR0115161A (en) 2003-10-21
MXPA03004019A (en) 2004-02-12
WO2002038829A1 (en) 2002-05-16
JP2004513240A (en) 2004-04-30
CN1478155A (en) 2004-02-25
DE10055215A1 (en) 2002-05-08
EP1346081A1 (en) 2003-09-24
CZ20031237A3 (en) 2003-10-15

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Owner name: WALTER HILLEBRAND GMBH & CO. GALVANOTECHNIK, GERMA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HILLEBRAND, ERNST-WALTER;REEL/FRAME:014366/0783

Effective date: 20030527

STCB Information on status: application discontinuation

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