1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 2535:2011Aerospace series Vacuumdeposition of cadmiumBS EN 2535:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 2535:2011. The UK
2、 participation in its preparation was entrusted to T e c h n i c a l Committee ACE/65, Non-metallic materials for aerospace purposes (excluding textiles).A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all
3、 the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 74876 9 ICS 49.040 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and
4、Strategy Committee on 31 July 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS EN 2535:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 2535 June 2011 ICS 49.040 English Version Aerospace series - Vacuum deposition of cadmium Srie arospatiale - Cadmiage sous vide Luft-
5、und Raumfahrt - Aufdampfen von Kadmium im Vakuum This European Standard was approved by CEN on 12 February 2011. 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 al
6、teration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language m
7、ade by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Est
8、onia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUR
9、OPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 2535:2011: EBS EN 2535:2011EN 2535:2011 (E) 2 Contents PageForeword 4 1 Scope 5 2 Normative refer
10、ences 5 3 Purpose of process .5 4 Limitation of process use .5 5 Definitions 6 6 Thickness .6 7 Apparatus and materials .6 7.1 Vacuum enclosure .6 7.2 Deposition material6 7.3 Masking material 6 8 Information for the processor 7 9 Condition of parts prior to processing 7 9.1 General 7 9.2 Stress rel
11、ief treatment .7 10 Process schedule 7 11 Pre-treatment 8 11.1 Degreasing .8 11.2 Abrasive blasting .8 12 Treatment 8 12.1 Suspension and clamping of parts 8 12.2 Evacuation of the enclosure (primary vacuum) .8 12.3 Sputter cleaning .8 12.4 Deposition 8 12.5 Flooding, venting .9 12.6 Removal 9 13 Po
12、st-treatment 9 13.1 Chromating .9 13.2 Additional protection .9 14 Removal of the coating .9 14.1 Chemical process 9 14.2 Mechanical process .9 15 Required characteristics 10 15.1 Appearance . 10 15.2 Thickness of the layer 10 15.3 Adhesion 10 15.4 Corrosion resistance 10 16 Inspection 10 16.1 Inspe
13、ction of vacuum deposited parts and samples 10 16.1.1 Appearance . 10 16.1.2 Inspection of the thickness of the coating . 10 16.1.3 Adhesion test 10BS EN 2535:2011EN 2535:2011 (E) 3 Page16.1.4 Corrosion test for steel .1117 Quality assurance 11 17.1 Approval of the processor 11 17.2 Process approval
14、 . 11 17.3 Acceptance 11 17.4 Reprocessing . 12 18 Health, safety and environmental aspects 12 19 Designation 12 BS EN 2535:2011EN 2535:2011 (E) 4 Foreword This document (EN 2535:2011) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After
15、 enquiries 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 ASD, prior to its presentation to CEN. This European Standard shall be given the status of a na
16、tional standard, either by publication of an identical text or by endorsement, at the latest by December 2011, and conflicting national standards shall be withdrawn at the latest by December 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of
17、patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
18、 Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 2535:2011EN 2535:
19、2011 (E) 5 1 Scope This European Standard defines the method for depositing cadmium layers according to the vacuum deposition process, for use in aerospace construction. According to this process, cadmium metal is vaporised under vacuum and deposited directly on the base material with an interlayer.
20、 The coating produced in this way is ductile and electrically conductive. This standard should be applicable whenever referenced. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. Fo
21、r undated references, the latest edition of the referenced document (including any amendments) applies. EN 2828, Aerospace series Adhesion test for metallic coatings by burnishing EN 9100, Aerospace series - Quality management systems - Requirements (based on ISO 9001:2000) and Quality systems - Mod
22、el for quality assurance in design, development, production, installation and servicing (based on ISO 9001:1994) EN ISO 1463, Metallic and oxide coatings Measurement of coating thickness Microscopical method EN ISO 2082, Metallic and other inorganic coatings - Electroplated coatings of cadmium with
23、supplementary treatments on iron or steel (ISO 2082:2008) EN ISO 2177, Metallic coatings Measurement of coating thickness Coulometric method by anodic dissolution (ISO 2177:2003) EN ISO 2178, Non-magnetic coatings on magnetic substrates Measurement of coating thickness Magnetic method (ISO 2178:1982
24、) EN ISO 2819, Metallic coatings on metallic substrates Electrodeposited and chemically deposited coatings Review of methods available for testing adhesion (ISO 2819:1980) ISO 4520, Chromate conversion coatings on electroplated zinc and cadmium coatings EN ISO 9227, Corrosion test in artificial atmo
25、spheres Salt spray tests ISO 4520, Chromate conversion coatings on electroplated zinc and cadmium coatings 3 Purpose of process This process enables any hydrogen absorption to be avoided. It ensures protection against corrosion, in particular for steels of Rm max. 1 450 MPa. It may be beneficial to
26、tensile bolts of Rm max. 1 250 MPa. 4 Limitation of process use The contact of cadmium-plated parts with titanium, titanium alloys, fuels and fuel line shall be avoided at temperature 3,2 mm) Class C: 5 m to 10 m (for bolts with a thread diameter 3,2 mm) 7 Apparatus and materials 7.1 Vacuum enclosur
27、e The vacuum enclosure shall contain the following equipment: a variable heating system for vaporisation of the cadmium; a rotating device to achieve a regular coating; a vaporising dish; a glow system and a vacuum gauge as well as an inspection window. Furthermore, a pump system is required, allowi
28、ng a vacuum of at least 6,65 10-3Pa to be reached. 7.2 Deposition material The cadmium used for deposition shall be at least 99,95 % pure. The mercury content shall not exceed the maximum level of 0,004 %. The quality shall be confirmed by certificate. 7.3 Masking material The masking materials used
29、, such as masking varnishes, lead or textile tapes, paper or aluminium foils shall not release gases during the process. BS EN 2535:2011EN 2535:2011 (E) 7 8 Information for the processor In addition to the designation in clause 19, the following information shall be stated: a) number of the substrat
30、e standard and metallurgical condition of the substrate; b) surface to be treated; c) non specific coating thicknesses of the cadmium coating and tolerances; d) if post-treatment by chromating does not have to be carried out. 9 Condition of parts prior to processing 9.1 General Unless otherwise spec
31、ified, all machining operations, moulding, brazing and welding treatments as well as heat treatments, shall be completed before plating. 9.2 Stress relief treatment The conditions for stress relief treatment of steel parts shall be determined according to the nature and hardness of the material. A s
32、light discoloration by superficial oxidation is permitted. Shot peening, if required, shall be carried out after stress relief treatment. 10 Process schedule Unless otherwise specified, the following process schedule is mandatory: a) degreasing; b) abrasive blasting; c) degreasing (if necessary, e.g
33、. to remove any abrasive residues); d) suspension in the device; e) evacuation of the enclosure; f) ionic etching (sputter cleaning) (if necessary); g) deposition; h) flooding and venting of the enclosure; i) removal; j) chromating; k) preservation or application of paint. BS EN 2535:2011EN 2535:201
34、1 (E) 8 11 Pre-treatment NOTE Chemical or electrochemical process such as acid pickling, electrolytic cathodic degreasing or processes causing hydrogen embrittlement are not permitted for steels of Rmmax. 1 450 MPa. 11.1 Degreasing The parts shall be cleaned by appropriate and qualified organic solv
35、ents. NOTE After pre-treatment the parts shall be coated within 4 h. Otherwise, the parts shall be stored for a short time either under vacuum, in an inert gas atmosphere, in anydrous ethanol, or in anydrous acetone. 11.2 Abrasive blasting The parts shall be cleaned by abrasive blasting in such a wa
36、y that the surface is of a uniform mat appearance. For this operation, care shall be taken to see that the compressed air is de-oiled by a special filter. Parts cleaned by abrasive blasting shall not be rougher than specified in the design documents for the finished cadmium-plated surface. After gri
37、t blasting, all parts shall be cleared of blasting medium residues, e.g. by blowing with oil free compressed air. Where wet blasting is used, the part shall be carefully dried after treatment. 12 Treatment 12.1 Suspension and clamping of parts The parts shall be placed in such a way that a regular d
38、eposition is ensured, if necessary by means of appropriate supporting jigs. Attachment magnets may also be used for attachment, but this requires demagnetisation of the parts after the cadmium-plating process. The parts may undergo the treatment several times to ensure a regular coating at the requi
39、red thickness. For each batch, the required test samples shall be put in the deposition device at the same time. 12.2 Evacuation of the enclosure (primary vacuum) Evacuation shall be carried out until a vacuum of at least 1,33 10-2Pa is obtained. 12.3 Sputter cleaning Before starting the deposition
40、operation, ionic etching shall be applied with a suitable inert gas (e.g. argon) to obtain a final cleaning of the parts. The part is used as a cathode. The current and etching time shall be selected according to the installation and the geometry of the part in order to ensure optimum cleaning. 12.4
41、 Deposition Before starting the actual deposition process, the operational vacuum shall be regulated according to the specific characteristics of the part. The deposition times for the required coating thickness shall be determined by preliminary tests. The depositions progress, especially the perfo
42、rmance of the rotating system, shall be monitored during the process. BS EN 2535:2011EN 2535:2011 (E) 9 It is permissible to re-load the vaporising dish several times with cadmium to obtain particularly thick layers. However, if the vacuum in the chamber has been disturbed, the vacuum shall be resto
43、red to its operational level before any further deposition. 12.5 Flooding, venting After deposition, clean dry air shall be admitted to the enclosure. The enclosure shall not be opened until the external pressure has been reached and it has been assured that no molten cadmium remains in the vaporisi
44、ng dish. 12.6 Removal When the enclosure has been opened and during removal, the parts shall not be touched with bare hands. The parts shall only be handled with clean gloves until their final treatment (e.g. chromating, greasing, oiling) is complete. The same standard of hygiene is required for sto
45、rage surfaces or packaging. 13 Post-treatment 13.1 Chromating A post-treatment by chromating shall be carried out according to EN 2437 within 8 h following the deposition. If parts are not to be chromated, this shall be indicated in the design documents. The colour is specified according to ISO 4520
46、 class 2-C. 13.2 Additional protection The nature and type of any additional protection after cadmium-plating shall be specified in the design document. 14 Removal of the coating 14.1 Chemical process Defective cadmium coatings shall be chemically removed with a solution which does not attack the ba
47、sic material (e.g. 100 g/l to 300 g/l ammonium nitrate solution at ambient temperature for approximately 10 min). The parts are then thoroughly rinsed in clean water and dried. 14.2 Mechanical process It is preferable to remove the cadmium coating by abrasive blasting, as this method avoids any embr
48、ittlement by hydrogen absorption. Care shall be taken during abrasive blasting so that the part is handled in such a way as to ensure uniform removal. However, this method shall only be used in self-contained installations. BS EN 2535:2011EN 2535:2011 (E) 10 15 Required characteristics 15.1 Appearan
49、ce All the surfaces coated under vacuum shall be of a regular mat appearance, however, a mother-of-pearl type surface is not a cause for rejection. The cadmium layer shall not have any blisters, pores, cracks, contamination or irregularities. It shall not have any powdery or dark areas. 15.2 Thickness of the layer It shall correspond to the indications defined in the design documents. 15.3 Adhesion The layer of cadmium shall satisfy the adhesion test according to 16.1.3. 15.4 Corrosion resistance Cadmium-plated and chromated parts shal
