1、STD-AECMA PREN 247L-ENGL 377b LOL23LL 0032308 TLIL Edition approved for publication 1996-01 -31 AECMA STANDARD NORME AECMA AECMA NORM The equivalent versions in French and Germen languages can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau 921 38 ISSY - LES - MOULINEAUX CE
2、DEX - FRANCE prEN 2491 Edition 1 January 1996 PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - B-1200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : 49.040.40 ENGLISH VERSION Aerospace series Molybdenum disulphide dry lubricants Coating methods S
3、rie arospatiale Lubrifiants solides base de bisulfure de molybdne Mthodes dapplication Luft- und Raumfahrt Trockenschmierstoff e auf Molybdndisulfid-Basis Beschichtungsverfahren This “Aerospace series“ Standard has been drawn up under the responsibility of AECMA (The European Association of Aerospac
4、e Industries). It is published on yellow paper in three equivalent versions (English, French, German). It will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. 0 aecma 1996 Copyright Association Europeene des Constructeurs de Materiel Aerospa
5、tial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 Scope This standard defines the coating methods and characteristics of molybdenum disulphide dry film lubricants to EN 3021 which may be applied to parts in titanium, tit
6、anium alloys, steel and corrosion resisting steel. 2 Purpose of process To reduce wear, risk of seizing and, in some cases, fretting corrosion. 3 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are
7、cited at the appropriate places in the text 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 edi
8、tion of the publication referred to applies. IS0 1463 Metallic and oxide coatings - Measurement of coating thickness - Microscopical method IS0 2431 Paints and varnishes - Determination of flow time by use of flow cups IS0 2859-1 Sampling procedures for inspection by attributes - Part 1 : Sampling p
9、lans indexed by acceptable quality level (AQL) for lot-by-lot inspection IS0 2884 Paints and varnishes - Determination of viscosity at a high rate of shear IS0 8080 Aerospace - Anodic treatment of titanium and titanium alloys - Sulphuric acid process EN 2000 Aerospace series - Quality assurance - EN
10、 Aerospace products - Approval of the quality system of manufacturers EN 2133 Aerospace series - Cadmium plating of steels with specified tensile strength I 1 450 MPa, copper, copper alloys and nickel alloys 1) EN 2516 Aerospace series - Passivating of corrosion resistant steels and decontamination
11、of nickel base alloys 1) EN 3021 Aerospace series - Molybdenum disulphide dry lubricants to be applied as a film - Technical specification 2) ASTM D 2510 : 1983 Standard test method for adhesion of solid film lubricants 3) 11 Published as AECMA Standard at the date of publication of this standard 2)
12、 In preparation at the date of publication of this standard 3) Published by : American Society for Testing and Materials (ASTM), 1916 Race Street, Philadelphia, PA 19103 Previous page is blank Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license wit
13、h AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA PREN 2qSL-ENGL L77b 10123LL 0012310 bTT M Page 4 prEN 2491 : 1996 4 Definitions For the purposes of this standard, the following definitions apply : 4.1 Batch Parts subjected to the same dry lubricant
14、 application at the same time under the same condition 4.2 Pre-production parts Parts representing future production 5 Apparatus 5.1 For application by dipping Container with a lid, stirring device and temperature control The apparatus shall be capable of applying the specified thickness, for exampl
15、e by controlling the speed of immersion and removal and by draining or centrifuging the parts. 5.2 For application by spraying A dry, oil free air fed gun shall be used, with settings adapted to the characteristics of the dry lubricant used and to the shape of the parts to be coated. Preferably a me
16、chanical stirring device in the reservoir NOTE 1 : A device allowing for rotation of the parts to be coated and the automatic displacement of the gun will give a more uniform application. NOTE 2 : Use of an aerosol spray does not always ensure acceptable reproducibility. Moreover, the propellant sha
17、ll not have any adverse effect on the substrate. 5.3 For curing An oven capable of temperatures prescribed by the lubricant manufacturer 6 Information for the processor - Designation of the dry lubricant to EN 3021 ; - number of the material standard and metallurgical condition of the latter ; - are
18、as to be processed ; - thickness of the dry lubricant, if necessary, (see table 1) ; - duration and temperature of curing. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without l
19、icense from IHS-,-,-STD-AECMA PREN 2471-ENGL 179b 1012311 0012311 53b Page 5 prEN 2491 : 1996 7 Surface roughness of parts prior to application It shall be specified on the drawing or in the definition documents. NOTE : The surface roughness is an important factor affecting adhesion and behaviour of
20、 the film in service. 8 Surface preparation 8.1 Anodising : IS0 8080, unless otherwise specified. Parts in titanium and titanium alloys 8.2 Parts in corrosion resisting steel Passivation : EN 251 6, unless otherwise specified. 8.3 Parts in steel Cadmium plating EN 21 33, without chromating. If neces
21、sary, the cadmium layer may be phosphated in an accelerated zinc phosphate bath to obtain a uniform and insoluble phosphate coating of a mass per unit area between 1 glm2 and 1,5 glm2 (.e. a thickness of about 0,002 mm). NOTE : If the part has been de-embrittled, prior activation of the cadmium plat
22、ing is necessary (e.g. in a potassium cyanide bath 30 g/l to 45 g/l for 15 s to 30 s at ambient temperature). 9 Coating It shall be performed : - within 24 h, after surface preparation ; all precautions shall be taken to prevent contamination or corrosion of the parts awaiting treatment ; - in a cle
23、an and dry environment, relative humidity between 40 % and 75 %, temperature (20 15) OC avoiding any operations liable to contaminate the surfaces to be treated. 9.1 Application by dipping - Adjust the viscosity of the bath (see IS0 2431 or IS0 2884) to the value given by the manufacturer of the pro
24、duct to be deposited. - If necessary, pre-heat the parts to about 50 OC. - Immerse the parts at a speed determined by tests on pre-production parts. - Keep the parts immersed for 2 s to 10 s. - Remove the parts at a speed determined by tests on pre-production parts. - Drain parts. - Dry parts avoidi
25、ng handling them. - If necessary, cure the coating in an oven. The temperature and duration shall comply with the values given by the manufacturer of the product to be deposited. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for
26、 ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA PREN 2Li9L-ENGL L99b W LOL23LL OOL23L2 472 Page 6 prEN 2491 : 1996 9.2 Application by spraying - Adjust the viscosity (see IS0 2431 or IS0 2884) to the value given by the manufacturer. - if necessary, pre-heat the
27、parts to approx. 50 OC. - Produce the coating by applying successive passes, the gun setting and its distance being determined by tests on pre-production parts. - Dry parts avoiding handling them. - If necessary, cure the coating in an oven. The temperature and duration shall comply with the values
28、given by the manufacturer of the product to be deposited. 9.3 Other applications Other application methods producing the same quality of deposit may be used (for example : barrel deposition). 10 Post-treatment If the tolerances of the parts necessitate mechanical finishing, it shall be performed by
29、honing, burnishing, barrel finishing or manual brushing according to the size of parts or the batch size. 11 Removal of the film The following processes are generally used separately or as a combination : - removal by dry or wet abrasive blasting with fine grain ; - chemical removal (by pickling or
30、solvents). Following removal of the film, the parts shall be subjected to a visual and dimensional inspection. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from
31、IHS-,-,-STD-AECMA PREN 2LiSL-ENGL L99b LOL23LL OOL23L3 309 m Page 7 prEN 2491 : 1996 1 2 Characteristics, requirements and test methods See table 1, Table 1 Characteristic 4ppearance Thickness Adhesion Heat curing class 2 2) Requirement 1) Uniform colour, a variation of this indicates incorrect dist
32、ribution of the fillers in the film. Absence of defects such as : scratches, pits, blisters, runs, indentations, foreign bodies, accumulation of particles, lack of uniformity or any other surface imperfection Unless otherwise specified (0,Ol f 0,003) rnrn After mechanical finishing (0,005 I0,002) mm
33、 No flaking, blisters, cracks The film shall not be damaged by a brief contact with a solvent. Test method disual inspection. Suitable method or IS0 1463 or with the purchasers agreement, a method based on measurement of the mass of the dry lubricant deposited In the case of dispute, IS0 1463 shall
34、be applied. ASTM D 2510 Procedure A for type A 2) ASTM D 2510 Procedure B for type B 2) Rub with a pad of cotton-wool impre gnated with a solvent (for examplt methy-ethyl-ketone) . 1) On parts, if not possible, on accompanying test pieces. 2) See EN 3021. Copyright Association Europeene des Construc
35、teurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AECMA PREN 2LiSL-ENGL LS7b LOL23LL OOL23L4 245 Page 8 prEN 2491 : 1996 13 Quality assurance 13.1 Approval of the processor See EN 2000 13.2 Pro
36、cess approval Before beginning production, the processor shall apply the coating on pre-production parts and/or test pieces as agreed between the purchaser and processor. All the tests required by this standard (see 12) shall be carried out on these coated pre-production parts and/or test pieces, un
37、less otherwise agreed between the purchaser and processor. If the test results are satisfactory for the purchaser, he shall give his written approval to commence production. The process schedule shall not be changed thereafter without the prior agreement of the purchaser. 14 Acceptance 14.1 Appearan
38、ce and thickness See table 1. Unless otherwise specified, sampling in accordance with IS0 2859-1 : - sample size code letter, table 1, special inspection level S3 ; - simple sampling plan for normal inspection ; - acceptance quality level (AQL) 1,5. 14.2 Adhesion See table 1. The inspection levei, t
39、he sampling pian and the acceptance quality level according to IS0 2859-1 shall be defined by the purchaser. 14.3 Heat curing See table 1. The inspection level, the sampling plan and the acceptance quality level according to IS0 2859-1 shall be defined by the purchaser. 15 Re-treatment After agreement of the purchaser, the parts not meeting the requirements may be reprocessed. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
