1、BRITISH STANDARD AEROSPACE SERIES BS EN 2808:1997 Anodizing of titanium and titanium alloys The European Standard EN2808:1997 has the status of a BritishStandard ICS 49.040BSEN2808:1997 This BritishStandard, having been prepared under the directionof the Engineering SectorBoard, was published undert
2、he authority of the Standards Board and comes intoeffect on 15August1997 BSI03-2000 The following BSI references relate to the work on this standard: Committee reference ACE/44 Draft for comment92/74993 DC ISBN 0 580 26698 2 Committees responsible for this BritishStandard The preparation of this Bri
3、tishStandard was entrusted to Technical Committee ACE/44, Protective treatments and finishes for aerospace purposes, upon which the following bodies were represented: Aluminium Finishing Association British Coatings Federation Ltd. Metal Finishing Association Ministry of Defence National Centre of T
4、ribology Oil and Colour Chemists Association Society of British Aerospace Companies Amendments issued since publication Amd. No. Date CommentsBSEN2808:1997 BSI 02-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Purpose of the process 3 3 Lim
5、itation of application of the process 3 4 Normative references 3 5 Definitions 3 6 Information for the processor 3 7 Condition of parts prior to processing 3 8 Pre-treatments 3 9 Treatment 4 10 Removal of the anodic coating 4 11 Required characteristics 4 12 Inspection method 4 13 Quality assurance
6、4 14 Health, safety and environmental aspects 5 15 Designation 5 Annex A (informative) Pickling of titanium and removal of the anodic coating 6 Annex B (informative) Anodizing 6 List of references Inside back coverBSEN2808:1997 ii BSI 02-2000 National foreword This BritishStandard has been prepared
7、by Technical Committee ACE/44 and is the English language version of EN2808:1997 Aerospace series Anodizing of titanium and titanium alloys, published by the European Committee for Standardization (CEN). EN2808:1997 was produced as a result of international discussions in which the United Kingdom to
8、ok an active part. Cross-references The BritishStandard corresponding to the European Standard referred to in the text is identical in number and title with that given in clause4. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards ar
9、e responsible for their correct 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 title page, pages2 to6, an inside back cover and a back cover.
10、 This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN2808 March1997 ICS 49.040.40 Descriptors: Aircraft industry, titanium,titanium al
11、loys, anodizing, specifications, cleaning, quality assurance, designation English version Aerospace series Anodizing of titanium and titanium alloys Srie arospatiale Anodisation du titane et des alliages de titane Luft- und Raumfahrt Anodisieren von Titan und Titanlegierungen This European Standard
12、was approved by CEN on1996-10-27. 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 bibliographical references concerning such natio
13、nal standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and not
14、ified 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, Sweden, Switzerland and UnitedKingdo
15、m. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 Copyright reserved to CEN members Ref. No. EN2808:1997 EEN2808:1997 BSI 02-2000 2 Foreword This European Standard has been prepare
16、d by the European Association of Aerospace Manufacturers (AECMA). After inquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its pres
17、entation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September1997, and conflicting national standards shall be withdrawn at the latest by September1997. According to the CEN/CENELEC I
18、nternal Regulations, the national standards organizations of 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 the Unit
19、edKingdom.EN2808:1997 BSI 02-2000 3 1 Scope This standard specifies the anodizing of titanium and titanium alloys. It shall be applicable whenever referenced. 2 Purpose of the process To improve the adhesion, especially of solid film lubricants, or to achieve a distinctive bluish violet colour 3 Lim
20、itation of application of the process This process does not apply to riveted or spot welded assemblies. 4 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the t
21、ext and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to appl
22、ies. EN2000, Aerospace series Quality assurance EN aerospace products Approval of the quality system of manufacturers. EN2497, Aerospace series Dry abrasive blasting of titanium and titanium alloys. 5 Definitions For the purposes of this standard, the following definitions apply: 5.1 batch unless ot
23、herwise specified, it comprises parts treated at the same time in the same bath 5.2 pre-production parts parts that are representative for future production 6 Information for the processor Designation, see15; number of the material standard and metallurgical condition of the latter; areas to be proc
24、essed, if necessary. 7 Condition of parts prior to processing All welding, brazing, heat treatments and machining operations (with the exception of those possibly performed on the anodic coating) shall have been completed before processing the part. 8 Pre-treatments 8.1 Cleaning by abrasive blasting
25、 The oxidized parts shall be cleaned by wet abrasive blasting with fine-grain alumina after agreement between the purchaser and processor or according to EN2497. 8.2 Solvent cleaning Greasy parts may be previously cleaned by suitable qualified solvents. The use of methyl alcohol is not permitted. Ch
26、lorinated solvents may cause stress corrosion cracking and shall only be used after agreement between purchaser and processor. 8.3 Alkaline cleaning 8.3.1 All parts shall be cleaned in a mild alkaline solution. Any suitable commercial products may be used. The concentration limits, temperature and i
27、mmersion time shall be defined by technical data provided by the manufacturer of the product.EN2808:1997 4 BSI 02-2000 8.3.2 Parts shall be rinsed immediately after cleaning in running tap water. Counter-current rinsing is recommended. Following rinsing, a water-break free surface is required. When
28、a break occurs, the parts shall be reprocessed to8.3.1. 8.4 Pickling 8.4.1 Pickling removes small abrasive particles and provides a mild etching action by chemical dissolution. 8.4.2 Pickling is performed in a solution of nitric and hydrofluoric acids of controlled composition to conditions agreed b
29、y the purchaser. A composition that has proved suitable is given in Annex A. 8.4.3 Parts shall be rinsed immediately after pickling in running tap water. Counter-current rinsing is recommended. 9 Treatment 9.1 The process used shall make it possible to meet the requirements specified in11. An exampl
30、e for an aqueous solution of sulphuric acid giving good results is shown in Annex B. The jigs or racks with spring contacts shall be made of titanium. 9.2 Parts shall be rinsed in tap water for a minimum of2min. Final rinsing shall be by immersion of the parts in deionized water (conductivityk 204S/
31、cm). Parts shall be dried, e.g.in clean compressed air, immediately after final rinsing. 9.3 Handling of anodized parts shall be kept to a minimum. Operators shall wear clean gloves to avoid contamination of the anodized surface. A dry lubricant or paint shall be applied, if appropriate, without del
32、ay after final drying. 10 Removal of the anodic coating SeeAnnex A. 11 Required characteristics The parts shall be of bluish violet colour matching, if required, an agreed colour sample made of the same titanium alloy and heat treated under the same conditions as the anodized parts. 12 Inspection me
33、thod Visual inspection with the naked eye 13 Quality assurance 13.1 Approval of the processor SeeEN2000. 13.2 Process qualification Prior to production, the processor shall treat the pre-production parts and/or test pieces determined by an agreement between the purchaser and processor. These coated
34、pre-production parts and/or test specimens shall be submitted to the inspection described in the present standard (see12) unless a special agreement between the purchaser and processor exists. If the results are accepted as satisfactory by the purchaser, he shall give a written approval to carry out
35、 the treatment. The procedure shall not be modified without previous approval from the purchaser. 13.3 Acceptance The appearance inspection (see11 and12) shall be carried out on the whole batch unless otherwise specified. The anodic coating shall be removed (see10) from parts not meeting the require
36、ments. They shall then be reprocessed (see9). In some special cases the purchaser may agree to a local touch-up by brushing, for example with a aqueous solution of sodium carbonate(8g/l to12g/l).EN2808:1997 BSI 02-2000 5 14 Health, safety and environmental aspects The locally applicable regulations
37、and laws shall be observed. 15 Designation EXAMPLE: EN2808:1997 6 BSI 02-2000 Annex A (informative) Pickling of titanium and removal of the anodic coating The solution shall be stirred prior to the processing of parts. Stirring during processing is recommended. The nitric/hydrofluoric acid ratio sha
38、ll remain within the fixed limit in order to avoid the absorption of hydrogen by the parts. The water shall contain a maximum of150ppm of dissolved solids. Annex B (informative) Anodizing The sulphuric acid concentration shall have a precision of 10%, with respect to the specified value. The electro
39、lyte may contain additional components authorized by the purchaser. The water conductivity shall bek 104S/cm. Nitric acid (HNO 3 ) : 180g/l to380g/l Hydrofluoric acid (HF) : 13g/l to21g/l Dissolved titanium : 1g/l Temperature : 15 C to30 C Immersion time : 20s to30s HNO 3 /HF ratio : 10 Sulphuric ac
40、id (H 2 SO 4 ) : 50g/l to400g/l Chloride (as NaCl) : 200ppm Time : necessary to obtain the desired colour Voltage : 15V to20V Current density (initial) : 0,2A/dm 2to0,4A/dm 2BSEN2808:1997 BSI 02-2000 List of references Seenational foreword.BS EN 2808:1997 BSI 389 Chiswick High Road London W4 4AL BSI
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