1、AEROSPACERECOMMENDED PRACTICEARP1611 REV. A Issued 1980-01Revised 1995-11Reaffirmed 2014-08Superseding ARP1611Quality Inspection Procedure, CompositesTracer Fluoroscopy and RadiographyRATIONALEARP1611A has been reaffirmed to comply with the SAE five-year review policy.1. SCOPE:1.1 Purpose:This docum
2、ent describes an inspection procedure for detecting, by use of a radiographic opaquetracer and fluoroscopy or radiography methods, flaws which have been produced as the result ofcutting, machining, or drilling operations in composite or laminate structures.1.2 Application:These instructions are appl
3、icable to composite materials, such as carbon/epoxy,fiberglass/epoxy, boron/epoxy, and other fibrous reinforcements and resin systems, such asorganic fiber reinforcement and polyimide, polyester, and thermoplastic resins.1.3 Safety - Hazardous Materials:While the materials, methods, applications, an
4、d processes described or referenced in thisspecification may involve the use of hazardous materials, this specification does not address thehazards which may be involved in such use. It is the sole responsibility of the user to ensurefamiliarity with the safe and proper use of any hazardous material
5、s and to take necessaryprecautionary measures to ensure the health and safety of all personnel involved.2. APPLICABLE DOCUMENTS:The following publications form a part of this document to the extent specified herein. The latestissue of SAE publications shall apply. The applicable issue of other publi
6、cations shall be the issuein effect on the date of the purchase order. In the event of conflict between the text of thisdocument and references cited herein, the text of this document takes precedence. Nothing in thisdocument, however, supersedes applicable laws and regulations unless a specific exe
7、mption hasbeen obtained.SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report isentirely voluntary, and its applicability and suitability for any particular use, including any patent infri
8、ngement arising therefrom, is the sole responsibility of the user.“SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments andsuggestions.Copyright 2014 SAE InternationalAll rights reserved.
9、No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical,photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) SAE
10、values your input. To provide feedbackTel: +1 724-776970 (outside USA) on this Technical Report, please visitFax: 724-776-0790http:/www.sae.org/technical/standards/ARP1611AEmail: CustomerServicesae.org |_SAE WEB ADDRESS: http:/www.sae.orgSAE INTERNATIONAL ARP1611A Page 2 of 7 2.1 SAE Publication:Ava
11、ilable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.AMS 2825 Material Safety Data Sheets2.2 U.S. Government Publications:Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue,Philadelphia, PA 19111-5094.MIL-STD-410 Nondestructive Testing Personnel Qualific
12、ations and Certification ReviewerMIL-STD-453 Inspection, Radiographic3. INSPECTION PROCEDURE:3.1 Description:The radiographic opaque (radiopaque) tracer material is applied to the area to be inspected andallowed to penetrate the flaws open to the surface. The tracer penetrates the flawed area bycapi
13、llary action and thereby allows the flaw to be detected and sized by fluoroscopy orradiographic procedures. The diiodobutane (DIB) tracer liquid leaves no trace of its presence48 h after penetration into a flaw (see 5.3 and 5.4).3.2 Types of Flaws:There are five primary types of flaws generated by c
14、utting, machining, or drilling of compositematerials. These flaws, depending on their size and on the design requirements for the part, maynecessitate repair of the composite structure or cause the structure to be rejected.3.2.1 Delamination: A separation between laminate plies as a result of intern
15、al or external stresses.Delaminations may occur on either the tool entrance or exit side of the composite or may bewithin the composite.3.2.2 Breakout: A splintering effect, usually on the exit side of a drilled hole or a cut piece. A breakout may be one or more plies thick.3.2.3 Microcracks: Intral
16、aminar resin cracks, usually running parallel to the cutting or ply direction.These cracks can range from 0.001 to 0.400 in (0.02 to 10.16 mm) in length and are sometimesdifficult to detect visually. Occasionally these cracks may run perpendicular to the ply directionduring certain machining operati
17、ons, such as routing. In some resins this may appear asrandom matrix cracking not caused by machining.SAE INTERNATIONAL ARP1611A Page 3 of 7 3.2.3.1 Matrix Cracking: Localized cracking confined to the pockets of resin within a composite(R) material. The cracks may cross to adjacent laminate layers b
18、ut remain confined to resinpockets and do not propagate through fibers. Matrix cracking within the interior of a partwould not normally be detected by this method.3.2.4 Fiber/Resin Pullout: Very small pieces of resin or composite fibers pulled away from the matrix.3.2.5 Shredding: Tearing of one or
19、more composite plies as a result of forces pulling materials awayfrom the composite. This problem is most prevalent in organic fiber composites and occurspredominately in the top or bottom plies.4. IMPLEMENTATION OF THE NONDESTRUCTIVE EVALUATION METHOD:4.1 Work Area Requirements: Work areas wherein
20、tracer fluoroscopy is to be performed shouldconform to the premises, equipment, and safety requirements of MIL-STD-453.4.2 Personnel Requirements:4.2.1 Personnel performing tracer fluoroscopy should be certified for radiographic inspection in(R) accordance with applicable specifications, such as MIL
21、-STD-410, and internal companystandards and regulations.4.2.2 Personnel should be instructed in the care, use, and handling of tracer material, and should be(R) thoroughly familiar with the safety recommendations of the material suppliers, including materialsafety data sheets (MSDS) conforming to AM
22、S 2825, or equivalent, for materials being used.4.3 Equipment Requirements:4.3.1 Radiation Source: A portable X-ray tube with a beryllium window is recommended. A focalspot size in the “micro-focus“ range is also recommended. In general, radiographic inspectionof composite materials is best accompli
23、shed utilizing relatively low kV and high mA. Ranges of10 to 110 kV and 5 to 40 mA are recommended and should be continuously variable.4.3.2 Fluoroscopy Screens: The screens should be sensitive to the low-energy X-rays required forcomposite inspection (see 5.2).4.3.3 Television Camera: The TV camera
24、 should be a light, portable unit with very high gain of about5000 Angstroms wavelength light and with a remote controlled focusing system.4.3.4 Video Scanning Display: The display should be capable of resolution of at least 600 lines perinch (23 lines per mm) and have a 14-in (356-mm) or larger dia
25、gonal screen measurement, withan external synchronization for use with edge enhancement.4.3.5 Video Tape System: A video tape system, capable of operating off a video display, andrecording the requirements per 4.3.4 is recommended if a permanent record is required of flawsdetected.SAE INTERNATIONAL
26、ARP1611A Page 4 of 7 4.3.6 Miscellaneous Equipment: An aspirator, rubber gloves, cotton swabs, lead identification tape,wiping cloths, and X-radiation counter are also required.4.4 Material Requirements:4.4.1 Tracer Material: Tracer material recommended is tetramethylene diiodide (1,4 diiodobutane,
27、orDIB) as follows (see 5.3):a. Chemical Formula: l(CH2)4lb. Specific Gravity: 2.33 0.01 at 23 C/4 Cc. Boiling Point: 147 to 152 F (64 to 67 C)4.4.1.1 Alternate Tracer Material: A less toxic tracer material of zinc iodide in alcohol is available.(R) This tracer will leave a residue of zinc iodide wit
28、hin the detected flaws (see 5.4). The solutionmay be prepared as follows:a. By Volume: 49% Zinc iodide (see 5.4)49% Alcohol (Reagent grade)2% Immunol 438 (wetting agent)4.4.1.2 New and/or additional tracer materials may be considered for use provided they exhibit similarradiographic density characte
29、ristics based upon experimentation.4.4.2 Composite Test Samples: Test samples (standards) should be prepared from the samecomposite material and of the same thickness as the parts, or a series of thicknesses toencompass the part thickness, to be inspected. Samples should be sufficiently large to bep
30、repared by drilling, cutting, or other fabrication processes that will be used on the parts.Flaws, such as delaminations or cracks, should be placed into the composite test samples sothey emanate from the hole or cut composite edge. The size of the test sample flaws should besuch that they can be de
31、tected by the tracer fluoroscopy or radiography system with a degreeof confidence required by the design considerations (see 5.5).4.5 Testing Procedure:4.5.1 Tracer Material Application:4.5.1.1 Tracer solution should be applied with a cotton swab or similar applicator and shouldadequately wet the co
32、mposite edge, hole, or other area to be inspected with sufficient liquid topenetrate flaws. In the case of zinc iodide tracer, the solution may be applied with an eyedropper, disposable pipette, or syringe.4.5.1.2 When applying DIB tracer material, as with any toxic material, personnel should wear r
33、ubber(R) gloves, aspirator, protective clothing, and eye protection and work in a well-ventilated area,especially if considerable tracer material is used.SAE INTERNATIONAL ARP1611A Page 5 of 7 4.5.1.3 Excess tracer material, which runs down the side of the composite part from the edge or hole,should
34、 be wiped dry immediately so as not to cause false positive indications. Use anindustrial wipe or similar absorbing material.4.5.1.4 Tracer material should be effective within 2 min and will retain most of its absorptioncharacteristics up to 6 h after application. No evidence of the DIB tracer mater
35、ial should bepresent after approximately 24 h and all DIB tracer material should evaporate within 48 h.4.5.1.5 Dispose of wipes, used to absorb excess tracer material, in accordance with the tracermanufacturers instruction.4.5.2 Area Marking: Each hole or edge to be inspected should be marked and id
36、entified with leadtape or other effective radiographic marking procedure to maintain adequate traceability to thepart and material, when such traceability is required.4.5.3 Fluoroscopic Inspection:4.5.3.1 Arrange the work piece, X-ray generation source, fluoroscopic screen (or X-ray film), TVcamera,
37、 and video output display as shown in Figure 1, or in a logical arrangement formaximum convenience and good visibility of the parts being inspected.4.5.3.2 If fluoroscopy or radiography is being undertaken in an exposed area, shielding of the X-raysource and subsequent radiation scatter monitoring m
38、ust be accomplished. Subsequentradiation leakage checks should be made with appropriate survey meter.4.5.3.3 Calibrate the system by applying tracer material onto the test sample as specified in 4.5.1 and(R) establish the correct voltage of the system to observe adequately the flaw in the standard.N
39、ote the voltage and distance settings for the test sample. The calibration sample should beof a thickness equivalent to the part and contain flaws of the minimum rejectable size andorientation.4.5.3.4 Set the image enhancement controls to give the best contrast and edge enhancement of theflawed area
40、. Note the settings and remove the test sample.4.5.3.5 Place the composite structure to be inspected into the fixture when an automated system isbeing used, or place the structure into the fluoroscopy or radiography unit for manualinspection. Check the settings developed on the standard and proceed
41、to inspect thecomposite, noting the indication of flaws from the video scanning display or film (see 5.5).4.5.3.6 Record the video scanning display (monitor) data onto video tape when permanent record ofthe flaws found by fluoroscopy is required.4.5.3.7 Recheck the calibration of the system with the
42、 appropriate standard after each production run.SAE INTERNATIONAL ARP1611A Page 6 of 7 FIGURE 1 - Schematic of Tracer Fluoroscopy System4.5.4 Inspected Part Marking: Acceptable parts which have satisfactorily passed inspection shouldbe marked in a manner and in a location that is harmless to the par
43、t; the markings should notbe removed, smeared, or obliterated by subsequent handling or fabrication processes.5. NOTES:5.1 The (R) is for the convenience of the user in locating areas where technical revisions, not editorialchanges, have been made to the previous issue of this specification. If the
44、symbol is next to thespecification title, it indicates a complete revision of the specification.5.2 Cesium iodide or gadolinium oxysulfide screens have been found to be satisfactory.5.3 The DIB in the tracer material (see 4.4.1) may react with some sealants and rubber compounds.When such compounds a
45、re present, the effect of the diiodobutane should be determined prior toproduction application of the tracer material.SAE INTERNATIONAL ARP1611A Page 7 of 7 5.4 Zinc iodide solution may be detrimental to further adhesive or painting processes. The potentialfor problems of this nature arising from in
46、spection with this tracer should be addressed prior totesting.5.5 Flaws, such as cracks and delaminations, which are widely separated may not be easily detecteddue to the lack of capillary action with the tracer material. Zinc iodide solution may be applied tothese areas with a syringe to enhance penetration.5.6 The fluoroscopic inspection process described herein has been classified under FederalStandardization Area Symbol “MISC.PREPARED BY AMS COMMITTEE “P
