AECMA PREN 4473-2009 Aerospace series Aluminium pigmented coatings for fasteners Technical specification Edition P 2《航空航天系列.铝涂层紧固件技术规范.版本P2》.pdf

1、ASD STANDARD NORME ASD ASD NORM prEN 4473 Edition P 2 September 2009 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 775 8131 - www.asd-stan.orgICS: Supersedes edition P 1 of Febru

2、ary 1999 Descriptors: ENGLISH VERSION Aerospace series Aluminium pigmented coatings for fasteners Technical specification Srie arospatiale Revtements alumino-organiques pour fixations Spcification technique Luft- und Raumfahrt Aluminium pigmenttete Beschichtungen fr Fixierungen Technische Lieferbedi

3、ngungen This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts of the

4、concerned Domain following member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and

5、 formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the sta

6、tus of a national standard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 30 September 2009 Comments should be sent within six months after the date of publication to ASD-STAN Mechanical Domain Copyright 2009 by ASD-STAN Copyright ASD-STAN Provide

7、d by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 2 Contents Page Foreword2 1 Scope 3 2 Normative references 3 3 Terms and definitions .4 4 Technical specifications .5 5 Quality assurance5 6 Requirements.5 Annex A

8、(normative) Test coupons for paint adhesion test 11 Annex B (normative) Test specimen for ohmic resistance measurement. 12 Annex C (normative) Lightning current simulation and swept lightning. 13 C.1 Lightning current simulation . 13 C.2 Test specimens distribution 13 C.3 Swept lightning (on counter

9、sunk head fastener) 13 C.4 Lightning current transfer condition (on protruding head fastener). 14 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Mechanical Domain. After inquiries and votes carried out in accordance with the rules of ASD-STAN defined in ASD-STAN

10、s General Process Manual, this standard has received approval for Publication. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 3 1 Scope This standard defines the qualification test cond

11、itions for aluminium pigmented coatings applicable to fasteners in titanium, titanium alloys, nickel base alloys and corrosion resisting steels. The aluminium pigmented coatings are not applicable to fasteners in non-corrosion resistant steels. Temperature class: 315 C 1)Type I : Coating with chroma

12、te and a cetyl alcohol lubricant. Type II : Coating without chromate and an cetyl alcohol lubricant. Type III : Coating with chromate, no additional lubricant. Type IV : Coating without chromate, no additional lubricant. 2 Normative references The following referenced documents are indispensable for

13、 the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2409, Paints and varnishes Cross cut test. ISO 9227, Corrosion tests in artificial atmospheres Salt s

14、pray tests. EN ISO 2812-1, Paints and varnishes Determination of resistance to liquids Part 1: Immersion in liquids other than water. EN 3032, Aerospace series Test method for dry film lubricants Thickness measurement. EN 4474, Aerospace series Aluminium pigmented coatings Coating methods. 2)EN 6117

15、, Specification for bolts with cetyl alcohol. 2)EN 9133, Aerospace series Quality management systems Quality Procedure for Aerospace Standards Parts. TR 4676, Aluminium pigmented coatings List of commercial products.3)NASM 1312-5, Fastener Test Methods; Method 5: Stress durability. 4)NASM 1312-12, F

16、asteners Test Methods, Method 12: Thickness of metallic coatings. 4)MIL-A-8625, Anodic coatings for aluminium and aluminium alloys. 5)1) Maximum operating temperature. 2) Published as ASD Prestandard at the date of publication of this standard. 3) Published as ASD Technical Report at the date of pub

17、lication of this standard. 4) Published by: Aerospace Industries Association, 1000 Wilson Boulevard, Suite 1700, Arlington, VA 22209-3928, USA. 5) Published by: Department of Defense (DOD), the Pentagon, Washington, D.C. 20301 USA. Copyright ASD-STAN Provided by IHS under license with AECMA Not for

18、ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 4 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 production lot product quantity of known composition (aluminium pigmented resin) prepared as one m

19、ixing using the same equipment 3.2 seam open surface defect 3.3 blister local convexity caused by a sub-surface inclusion of gas or liquid 3.4 nodule localized buildup or unmixed solid particles 3.5 pit void, hole in the surface as caused, for example, by corrosion 3.6 porosity fine holes or pores w

20、ithin the coating 3.7 functional surfaces functional surfaces are defined as surfaces in contact with mating structure and threaded portion such as screws: under head bearing surface, shank, lead-in radius and thread surface if applicable; nuts: bearing surfaces, thread surface; spherical washers: b

21、earing surfaces; swaged collars: all surfaces. 3.8 generic part familly of similar parts such as: screws; nuts and threaded collars; lockbolts; swaged collars; solid rivets; blind bolts; bushes; spherical washers. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduct

22、ion or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 5 4 Technical specifications 4.1 Product TR 4676 gives the list of aluminium pigmented coating commercial products. Product to be applied shall conform to environmental, work safety and public health European regulations. 4.

23、2 Product composition The preparation method and product composition shall be defined by the manufacturer. The latter must peremptorily notify its users of any change subsequent to qualification. The product shall not contain chemical compounds as listed below : lead, graphite, type II and IV shall

24、not contain hexavalent chromate. 4.3 Product application Product must be applied in accordance with EN 4474. The resin curing temperature must be lower than the last ageing treatment of the material to be coated by at least 10 C. Product may be applied in several coats but shall only have one curing

25、 (polymerization), pre heating (flash-off) is acceptable for each coat. 5 Quality assurance 5.1 Qualification EN 9133 All coating qualification tests shall be done on fasteners and according to Table 1. For fastener qualification only paragraphes 6.1 to 6.3 apply. 5.2 Acceptance Acceptance is done t

26、hrough fasteners lots for appearance, thickness and adhesion. Sampling 3 per generic part or coating application process and test method in accordance with sections 6.1 (Appearance), 6.2 (Thickness) and 6.3 (Adhesion). 6 Requirements See Table 1. All the tests are to be carried out after application

27、 according to EN 4474. When cetyl alcohol is added to type III or IV, they shall be qualified according to type I or II. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 6 Table 1 Section

28、 Characteristic Requirement Inspection and test method Sampling for qualification 6.1 Appearance The coating shall be smooth, uniform color, and shall be free of pinholes, porosity, blisters, nodules, pits, or other harmful imperfections. Visual examination 10 per generic part External threaded fast

29、eners:The coating thickness shall be between 5 m and 13 m on all functional surfaces as defined in 3.7. Determination of coating thickness shall be made by any of the methods specified in NASM 1312-12. 6.2 Thickness Internal threaded fasteners: The coating thickness shall be between 5 m and 20 m on

30、all functional surfaces as defined in 3.7. In case of conflict the micrographic examination shall be chosen. 10 per generic partor coating application process 6.3 Adhesion The coating must remain continuously bonded to the basis material. Class 0 ISO 2409 If fastener geometry does not alllow ISO 240

31、9 adhesion test, the coating must be cut through to the base material on the largest plain surface of the part. Press the tape firmly to the cut on the plain surface of the fastener and remove the tape in one abrupt motion perpendicular to the fastener surface. Any evidence of coating separation whe

32、n examined at approximately 4X is cause for rejection. 5 per generic part, material type or coating application process 6.4 Heat resistance The coating must remain continuously bonded to the basis material. No powder shall be detected by visual inspection. Class 0 Expose the coated test part to 315

33、C for 4 h. Air cool and carry out the adhesion test (see 6.3). ISO 2409. 4 screws continued Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 7 Table 1 (continued) Section Characteristic R

34、equirement Inspection and test method Sampling for qualification Immersion according to EN ISO 2812-1 inside : Kerosene: Method 1 = Full immersion 1 000 h at 70 C min in Kerosene or equivalent containing 0,2 % methyl cellosolve; Hydraulic fluid: Method 1 = Full immersion 1 000 h at 70 C min in phosp

35、hate ester hydraulic fluid type IV A. 6.5 Resistance to fuels and hydraulic fluids The coating shall not show evidence of blistering or loss of adhesion. Class 0 Adhesion test as per ISO 2409 2 screws Immersion of the coated test pieces: 24 h at room temperature in three products: benzylic alcohol a

36、nd dimer acid; diestone. 6.6 Resistance to stripper agents and to solvents The coating shall no show evidence of blistering or loss of adhesion. Class 0 Adhesion test as per ISO 2409 2 screws 6.7 Embrittlement 72 h at a tensile load of 80 % of minimum specified UTS, fasteners shall withstand the imp

37、osed loading conditions without any breaking or craking. NASM 1312-5 4 screws per material type identified as sensitive 6.8 Galvanic corrosion The countersinks and the surface area of the aluminium blocks around the coated fasteners shall show, by visual observations, no more corrosion than the corr

38、esponding areas with the cadmium plated fastener control blocks. General surface corrosion on the back of the panels shall not be considered in evaluating the protective qualities of the coating. Place coated countersunk head titanium bolts in a 7075 T6 aluminium alloy block defined in Annex A. The

39、assembled block shall be exposed for 336 h in neutral salt spray (NSS) ISO 9227. 3 screws continued Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 8 Table 1 (continued) Section Characte

40、ristic Requirement Inspection and test method Sampling for qualification Place coated countersunk head bolts in a 7075 T6 aluminium alloy block defined in Annex A: Specimen manufacture: plate shall be anodised and coated with aircraft primer paint prior to drilling and countersinking; fastener insta

41、llation; appropriate solvent cleaning + scouring pad + tack rag + chromate free external paint scheme. Tests preparation: Cross cut according to ISO 2409. Adhesion tests: 6.9 Paint Adhesion Class 0 at initial stage Class 3 after water immersion on initial stage; after water immersion 336 h at room t

42、emperature (Distilled or deionised water with 5,5 1 M.cm). 6 screws 6.10 Electrical conductivity and lightning The ohmic resistance shall be below 10 m. No overheating above 50 C shall be detected. No sparking shall occurrs during lightning test. The lightning test is not mandatory. Tests to be perf

43、ormed on 4,8 mm bolt diameter with interference of (40 10) m. The coating to qualify shall be applied to the element on which it is applicable (bolt, nut, lockbolt, collar, ). In case the coating shall be qualified on bolt, the nut to be used shall be cadmium plated steel. In case the coating shall

44、be qualified on lockbolt, the collar to be used shall be Chemical Conversion Coating on aluminium. In case the coating shall be qualified on nut, the bolt to be used shall be Resin Based Aluminium on titanium. Ohmic resistance to be measured between points A and B (see specimen in Annex B) under a c

45、urrent of 10 A. Swept lightning current and lightning current transfer in accordance with Annex C. 48 per generic part continued Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 4473:2009 (E) 9 Table 1

46、 (continued) Section Characteristic Requirement Inspection and test method Sampling for qualification 6.11 Interference fit This test is only applicable to the following generic parts: screws; lockbolts. Types I and II: The average of the 5 installations shall have an installation force of 34 000 N

47、or less, without a single installation force higher than 37 000 N. Types III and IV: The average of the 5 installations shall have an installation force of 11 000N or less, without a single installation force higher than 13 000 N. For all coating types, insertion load versus travel F = f (l) curves

48、shall be recorded and shall not present any discontinuities except at the interface. The removal load shall not exceed more than 25 % of the highest value measured during installation. Cetyl alcohol additional lubrication per EN 6117. Types I and II: Five samples of 12,7 mm (1/2“) diameter fasteners shall be coated per the requirements of this specification. Samples shall be installed in two 7075 T6 plates 25,4 mm thick each (both plates must be positioned and then assembled prior to holes drilling and chamfering). Hole surface texture Ra 0,8 m. Interfe