1、BRITISH STANDARD BS EN ISO 4524-3:1995 Incorporating Amendment No.1 Metallic coatings Test methods for electrodeposited gold and gold alloy coatings Part3: Electrographic tests for porosity The European Standard EN ISO4524-3:1995 has the status of a British StandardBSENISO4524-3:1995 This British St
2、andard, having been prepared under the directionof the Surface Coatings(other than Paints) Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 30May1986 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference SRC/
3、5 Draft for comment 81/50885 DC ISBN 0 580 15119 0 Committees responsible for this BritishStandard The preparation of this British Standard was entrusted by the Surface Coatings(other than Paints) Standards Committee(SRC/-) to Technical Committee SRC/5, upon which the following bodies were represent
4、ed: Assay Offices Committee of Great Britain British Jewellers Association British Metal Finishing Suppliers Association British Telecommunications plc Cutlery and Silverware Association Design and Research Centre for the Gold, Silver and Jewellery Industries Electronic Engineering Association Insti
5、tute of Metal Finishing Institution of Corrosion Science and Technology Metal Finishing Assn. Ministry of Defence National Association of Goldsmiths of Great Britain and Ireland Amendments issued since publication Amd. No. Date of issue Comments 8479 July1995 Indicated by a sideline in the marginBSE
6、NISO4524-3:1995 BSI 04-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope and field of application 3 2 Cadmium sulfide paper test 3 3 Nioxime paper test 3 4 Dye-transfer paper test 1 4 5 Dye-transfer paper test2 4 6 Electrographic gelatine film tes
7、t 4 7 Test report 5 Publications referred to Inside back coverBSENISO4524-3:1995 ii BSI 04-2000 National foreword This Part of BS6670 has been prepared under the direction of the Surface Coatings(other than Paints) Standards Committee. It is identical with ISO4524-3:1985 1)“Metallic coatings Test me
8、thods for electrodeposited gold and gold alloy coatings Part3: Electrographic tests for porosity” prepared bySub-committee3, Electrodeposited coatings and related finishes of Technical Committee107, Metallic and other non-organic coatings, of the International Organization for Standardization(ISO) w
9、ith the active participation and approval of the UK. In1994 the European Committee for Standardization(CEN) accepted ISO4524-3:1985 as European Standard EN ISO4524-3:1994. As a consequence of implementing the European Standard this British Standard is renumbered as BS EN4524-3:1995 and any reference
10、 to BS6670-3 should be read as a reference to BS EN ISO4524-3:1995. A number of the Parts of BS6670 are intended to replace certain of the appendices of BS4292:1968, “Electroplated coatings of gold and gold alloy”. Now that the test methods required for this purpose have been published, BS4292:1968
11、is being revised. Upon completion of the revision it will no longer contain the texts of test methods and BS4292:1968 will be withdrawn. At present, the following Parts of BS6670 have been published. Part1: Determination of coating thickness; Part2: Environmental tests; Part3: Electrographic tests f
12、or porosity; Part4: Determination of gold content; Part5: Adhesion tests. Further Parts of this standard will be prepared, if required. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a BritishStandard without deviation. Some termi
13、nology and certain conventions are not identical with those used in BritishStandards; attention is drawn especially to the following. The comma has been used as a decimal marker. In BritishStandards it is current practice to use a full point on the baseline as the decimal marker. In BritishStandards
14、 it is current practice to use the symbol “L” for litre rather than “l” and to use the spelling “sulphur”, etc. instead of “sulfur”, etc. Wherever the words “this part of ISO4524” appear, referring to this standard, they should be read as “this Part of BS6670”. This Part describes methods of test on
15、ly and should not be used or quoted as a specification. Reference to this Part should state that the method of test used is in accordance with BS6670-3. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their cor
16、rect application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, pages2 to6, an inside back cover and a back cover. This standard has been
17、 updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) Corrected and reprinted March1986.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO4524-3 January1995 ICS 25.220.40 Descriptors: Metal coatings,
18、electrodeposited coatings, gold plating, decorative coatings, tests, porosity measurement, coatings, protective coatings, determination, porosity English version Metallic coatings Test methods for electrodeposited gold and gold alloy coatings Part3: Electrographic tests forporosity (ISO4524-3:1985)
19、Revtements mtalliques Mthodes dessai des dpts lectrolytiques dor et dalliages dor Partie3: Dtermination lectrographique de la porosit (ISO4524-3:1985) Metallische berzge Prverfahren fr elektrolytisch abgeschiedene berzge aus Gold und Goldlegierungen Teil3: Elektrografische Prfungen auf Porositt (ISO
20、4524-3:1985) This European Standard was approved by CEN on1994-10-03. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographi
21、cal references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions(English, French, German). A version in any other language made by translation under the responsibility of a CEN m
22、ember into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, S
23、weden, Switzerland andUnited Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 Copyright reserved to all CEN members Ref.No.ENISO4524-3:1995EENISO4524-3:1995 2 BSI 04-2000 Fo
24、reword This European Standard has been taken over by the Technical Committee CEN/TC262, Protection of metallic materials against corrosion, from the work of ISO/TC107, Metallic and other inorganic coatings, of the International Organization for Standardization(ISO). This document was submitted to th
25、e formal vote and was adopted by CEN as a European Standard. This European Standard shall be given the status ofa national standard, either by publication of an identical text or by endorsement, at the latest by July1995, and conflicting national standards shall be withdrawn at the latest by July199
26、5. In accordance with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Ki
27、ngdom.ENISO4524-3:1995 BSI 04-2000 3 1 Scope and field of application This part of ISO4524 specifies five electrographic tests for assessing the porosity of electrodeposited gold and gold alloy coatings for engineering, and decorative and protective purposes. 2 Cadmium sulfide paper test 2.1 Applica
28、bility This method is suitable for the examination of gold coatings on copper. 2.2 Materials During the test, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity, 2.2.1 Cadmium sulfide paper Use filter or duplicating paper
29、of adequate wet strength, with a texture that will produce sharp and uniform electrograms. Soak the paper for10min in a fresh10%(m/m) solution of cadmium chloride hemipentahydrate(CdCl 2 .2,5H 2 O) containing0,1%(V/V) of hydrochloric acid (HCl, 1,16 to1,18g/ml). Remove the excesssolution with blotti
30、ng paper. Allow the paper to dry partially and then immerse itin a fresh50g/l solution of sodium sulfide(Na 2 S) for30s, after which time the paper should be a uniform yellow colour(indicating complete precipitation of cadmium sulfide, CdS). Wash the paper in running water for approximately1h, then
31、hang it up to dry. 2.2.2 Moistened blotting paper Soak a good quality white blotting paper in water and dry it to a degree that consistently produces sharply defined electrograms. 2.3 Procedure Lightly brush the electroplated coating to removeloose dust and debris, then degrease it in1,1,1-trichloro
32、ethane vapour or other suitable solvent. Place a piece of the cadmium sulfide paper on the electroplated specimen(which acts as the anode). On the other face of the cadmium sulfide paper, place a piece of the moistened blotting paper(2.2.2), followed by a high purity clean aluminium or stainless ste
33、el platen(which acts as the cathode). Compress the assembly so that the pressure between the cadmium sulfide paper and the specimen is uniform and between1,4 and1,7 MPa. While under compression, pass a smooth ripple-free d.c. current from a source not exceeding12V. Set the current density initially
34、at7,5mA/cm 2of anode area and pass for30s. Allow the electrogram produced on the cadmium sulfide paper to dry. The presence of any defect in the electroplated coating is revealed by a corresponding brown stain on the paper. NOTEIf an overall black stain is obtained in this test, either the electroly
35、te content of the papers or the current density is toohigh. 3 Nioxime paper test 3.1 Applicability This method is suitable for the examination of gold coatings on undercoats of nickel or tin-nickel alloy. 3.2 Materials During the test, use only reagents of recognized analytical grade and only distil
36、led water or water of equivalent purity. Nioxime paper. Soak filter or duplicating paper for10min in an8g/l solution of nioxime(cyclohexan-1,2-dione dioxime). Remove the excess solution by blotting and hang the paper up to dry. 3.3 Procedure Lightly brush the electroplated coating to removeloose dus
37、t and debris, then degrease it in1,1,1-trichloroethane vapour or other suitable solvent. Moisten a piece of the nioxime paper(3.2) with water. Remove excess water by blotting. Place the treated nioxime paper on the electroplated specimen(which acts as the anode). On the other face of the nioxime pap
38、er, place a piece of the moistened blotting paper(2.2.2), followed by a high purity clean aluminium or stainless steel platen(which acts as the cathode). Compress the assembly so that the pressure between the nioxime paper and the specimen is uniform and between1,4 and1,7MPa. While under compression
39、, pass a smooth ripple-free d.c. current from a source not exceeding12V. Set the current density initially at7,5mA/cm 2of anode area and pass for30s. Expose the electrogram produced on the nioxime paper to ammonia vapour and then allow to dry. The presence of any defect in the electroplated coating
40、is revealed by a corresponding pink stain on the paper. When electroplated on copper, defects in the nickel or tin-nickel undercoat are revealed as green stains.ENISO4524-3:1995 4 BSI 04-2000 4 Dye-transfer paper test1(alternative to the test described in clause2) 4.1 Materials During the test, unle
41、ss otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. Dye-transfer paper. Soak a piece of dye-transfer paper for30min in a freshly prepared solution containing0,01mol/l of sodium chloride (NaCl) and0,01mol/l of sodium carbonate(
42、Na 2 CO 3 ) made by dissolving0,58g of sodium chloride and1,06g sodium carbonate together in1litre of water. Remove the excess solution with blotting paper. NOTEDye-transfer paper may be obtained from some suppliers of photographic materials. 4.2 Procedure Remove loose dirt and debris from the elect
43、roplated coating with a soft brush and then degrease it in1,1,1-trichloroethane vapour or other suitable solvent. Place a piece of the damp dye-transfer paper(4.1) emulsion side down on the electroplated specimen(which acts as the anode), followed by ahigh purity clean aluminium or stainless steel p
44、laten(which acts as the cathode). Compress theassembly so that the pressure between the dye-transfer paper and the specimen is uniform andbetween1,4 and1,7MPa. While under compression, apply a fixed potential of4V d.c. for30s. Remove the dye-transfer paper and developit in a saturated ethanolic solu
45、tion of dithiooxamide(dissolve0,25g of dithiooxamide in100ml of ethanol by gentle warming; if necessary, filter when cold before use) for30s. Wash the electrogram produced in cold running water and allow to dry. The presence of any defect inthe plated coating is revealed by a corresponding dark oliv
46、e-green stain on the paper. It is essential that the test papers produced in carrying out the test be rinsed in hot water and carefully dried, on completion of the tests. NOTEIt is advisable to use tweezers for immersing the paper in the dithiooxamide solution because it can produce persistent black
47、 stains on the fingers. 5 Dye-transfer paper test2 (alternative to the test described in clause3) Follow the procedure described in clause4 but use adeveloping solution consisting of a0,5%(m/m) ethanolic solution of nioxime (cyclohexan-1,2-dione dioxime). The presence of any defect in the electropla
48、ted coating is revealed by a corresponding pink stain on the paper. When plated on copper, defects in the nickel or tin-nickel undercoat are revealed as green stains. It is essential that the test papers produced in carrying out the test be rinsed in hot water and carefully dried, on completion of t
49、he tests. NOTES (on tests given in clauses2 to 5) 1The tests described in clauses 2 and 3 do not call for anelectrolyte to be used and rely on ions from the test paper andbacking paper to provide conductivity. In some cases, it is necessary to soak the test papers in a solution of a suitable electrolyte, for example for dyetransfer paper(seeclause4) in a0,1mol/l solution of sodium nitrate (NaNO 3 ). 2The tests described in clauses4 and 5 are more sensitive than those given in clauses 2 and 3, i.e.microporosity ismore easily detect
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