1、AEROSPACE MATERIAL SPECIFICATIONAMS3688 REV. BIssued 1974-03Revised 1988-10Reaffirmed 2014-08Superseding AMS3688AAdhesive, Foaming, Honeycomb Core Splice, Structural-55 C to +82 C (-65 F to +180 F) RATIONALEAMS3688B has been reaffirmed to comply with the SAE five year review policy._SAE Technical St
2、andards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole
3、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 and suggestions.Copyright 2014 SAE InternationalAll rights reserved. No part of this publication may be rep
4、roduced, 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)Tel: +1 724-776-4970 (outside USA)Fax: 724
5、-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AMS3688B1.adhesive in the form of paste or sheet.1.2 Application: Primarily for use in splicing aluminum alloy
6、 or nonmetallichoneycomb core and for providing a shear tie between core edges and insertsor edge members in honeycomb assemblies for use over the range-55 to +82C (-65 to +180F). It is useful for filling gaps between corefaces which are inserted into channels or similar areas where bondingpressure
7、cannot be obtained.1.3 Safety - Hazardous Materials: While the materials, methods, applications,and processes described or referenced in this specification may involve theuse of hazardous materials, this specification does not address the hazardswhich may be involved in such use.It is the sole respo
8、nsibility of theuser to ensure familiarity with the safe and proper use of any hazardousmaterials and to take necessary precautionary measures to ensure the healthand safety of all personnel involved.2. APPLICABLE DOCUMENTS:The following publications form a part of thisspecification to the extent sp
9、ecified herein. The latest issue of AerospaceMaterial Specifications shall apply. The applicable issue of other documentsshall be as specified in AMS 2350.2.1 SAE Publications: Available from SAE, 400 Commonwealth Drive, Warrendale,PA 15096.SCOPE:1.1 Form: This specification covers a foaming-type, h
10、eat-curing, resin-base2.1.1 Aerospace Material Specifications:AMS 2350 - Standards and Test MethodsAMS 2825 - Material Safety Data SheetsAMS 4037 - Aluminum Alloy Sheet and Plate, 4.4Cu - 1.5Mg - 0.60Mn(2024-T3 Flat Sheet, -T351 Plate)AMS 4348 - Honeycomb Core, Aluminum Alloy, Corrosion Inhibited, f
11、orSandwich Construction, 5052, 350 (175)SAE INTERNATIONAL AMS3688B Page 2 of 112.2 U.S. Government Publications: Available from Commanding Officer, NavalPublications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120.2.2.1 Military Specifications:MIL-C-7438 - Core Material, Aluminum, for Sa
12、ndwich ConstructionMIL-A-25463 - Adhesive, Film Form, Metallic Structural SandwichConstruction2.2.2 Military Standards:3. TECHNICAL REQUIREMENTS:3.1 Material: The adhesive shall be a heat-curing, nominally 120C (250F),resin system containing fillers and foaming agents necessary to meet therequiremen
13、ts of 3.2 and 3.3. The adhesive shall have low-sagging propertiesto ensure complete filling of core-splice gaps when splices are cured in avertical position. Adhesive shall be suitable for splicing honeycomb corewithout damage to core node bonds located adjacent to the splice.3.1.1 Sheet Adhesive: S
14、hall be supplied as an unsupported sheet with a suitablenonadhering separator film on both surfaces.3.1.2 Paste Adhesive: Shall be supplied as a thixotropic paste, single-componentor two-part system, suitable for extrusion from a disposable cartridge orcaulking gun.3.2 Properties of Uncured Adhesive
15、: Adhesive, as received, shall conform to thefollowing requirements;tests shall be performed on the adhesive supplied andin accordance with test procedures specified herein:3.2.1 Storage Life:3.2.1.1 Single component adhesive, packaged as specified herein, shall meet the3.2.1.2 Two-part paste system
16、, as specified herein, shall meet the requirements of3.3 after storage at the temperature and for the time specified by themanufacturer, but not less than 3 months. Manufacturers specifiedstorage life shall begin at date of receipt from manufacturer.MIL-STD-794 - Parts and Equipment, Procedures for
17、Packaging and Packing ofrequirements of 3.3 after storage at a maximum temperature of-18C (0F) for up to 3 months from date of receipt from manufacturer.SAE INTERNATIONAL AMS3688B Page 3 of 113.2.2 Working Life: Single-component adhesive, and two-part paste systems mixedin accordance with manufactur
18、ers instructions, shall meet therequirements of 3.3 for any time up to 48 hr after exposure to a relativehumidity of 50 - 70% and a temperature of 21 - 27C (70 - 80F); pasteadhesive shall remain extrudable for this time period.3.3 Properties of Cured Adhesive: Shall be as follows, determined on spec
19、imensprepared as in 4.5 and cured at 120C 5 (250F 10) for 60 min 5 usinga heat-up rate of 2 - 3C (3 - 5F) minute.3.3.1 Curing Properties:3.3.1.1 Sagging, maximum 0.05 in. (1.3 mm) 4.5.13.3.1.2 Expansion Ratio, minimum 1.7 4.5.2 or4.5.33.3.1.3 Peak ExothermTemperature, maximum 177C (35OF)3.3.2 Cured
20、Properties:3.3.2.1 Density, maximum3.3.2.2 Beam ShearStrength, minimumAt -55C ( -65F)At +24C (+75F)At +82C (+180F)40 lb per cu ft (640 kg/m3)720 psi (4.95 MPa)720 psi (4.95 MPa)500 psi (3.45 MPa)4.5.54.5.63.4 Quality: Adhesive, as received by purchaser, shall be uniform in qualityand condition, smoo
21、th, homogeneous, and free from foreign materials and fromimperfections detrimental to usage of the adhesive.(O.25 mm). Width and length shall be 12 x 24 in. (300 x 600 mm) or3.5 Tolerances of Sheet Adhesive: Thickness shall be as specified, O.010 inchas specified, +0.250 inch (+6 mm), -0.125 in. (-3
22、 mm). Width and length ofspecially slit foam shall be as specified, 0.030 in. (0.75 mm).4 QUALITY ASSURAN PROVISIONS:4.1 Responsibility forInspection:The vendor of adhesive shall supply allsamples for vendors tests and shall be responsible for performing allrequired tests.required by 4.6.Results of
23、such tests shall be reported to the purchaser asPurchaser reserves the right to sample and to perform anyconfirmatory testing deemed necessary to ensure that the adhesive conformsto the requirements of this specification.SAE INTERNATIONAL AMS3688B Page 4 of 114.2 Classification of Tests:4.2.1 Accept
24、ance Tests: Tests to determine conformance to requirements forexpansion ratio (3.3.1.2) and beam shear strength at 24C (75F) (3.3.2.2) are classified as acceptance tests and shall be performed to representeach lot.4.2.2 Preproduction Tests: Tests to determine conformance to all technicalrequirements
25、 of this specification are classified as preproduction testsand shall be performed prior to or on the initial shipment of adhesive toa purchaser, when a change in material, processing, or both requiresreapproval as in 4.4.2, and when purchaser deems confirmatory testing tobe required.4.2.2.1 For dir
26、ect U.S. Military procurement, substantiating test data, and,when requested, preproduction test material shall be submitted to thecognizant agency as directed by the procuring activity, contractingofficer, or request for procurement.4.3 Sampling: Shall be as follows:4.3.1 For Acceptance Tests: Suffi
27、cient adhesive shall be taken at random fromeach lot to perform all required tests. The number of determinations foreach requirement shall be as specified in the applicable test procedureor, if not specified therein, not less than three.4.3.1.1 A lot shall be all adhesive produced in a single produc
28、tion run from thesame batches of raw materials and presented for vendors inspection atone time. An inspection lot shall not exceed 500 lb (225 kg) and may bepackaged in smaller quantities and delivered under the basic lotapproval provided lot identification is maintained.4.3.1.2 When a statistical s
29、ampling plan and acceptance quality level (AQL) forthe adhesive have been agreed upon by purchaser and vendor, samplingshall be in accordance with such plan in lieu of sampling as in 4.3.14.3.2 For Preproduction Tests: As agreed upon by purchaser and vendor. Onlyone panel need be tested for peak exo
30、therm temperature (3.3.1.3).4.4 Approval:4.4.1 Sample adhesive shall be approved by purchaser before adhesive forproduction use is supplied, unless such approval be waived by purchaser.Results of tests on production adhesive shall be essentially equivalent tothose on the approved sample.and the repo
31、rt of 4.6.1 shall state that such plan was used.SAE INTERNATIONAL AMS3688B Page 5 of 114.4.2 Vendor shall use ingredients, manufacturing procedures, processes, andmethods of inspection on production adhesive which are essentially thesame as those used on the approved sample adhesive. If necessary to
32、 makeany change in ingredients, in type of equipment for processing, or inmanufacturing procedures, vendor shall submit for reapproval a statementof the proposed changes in material, processing, or both and, whenrequested, sample adhesive. Production adhesive made by the revisedprocedure shall not b
33、e shipped prior to receipt of reapproval.4.5 Test Methods:4.5.1 Sagging: The sagging characteristics of an adhesive shall be determinedby fabricating a beam shear specimen in accordance with 4.5.6.1, with noface bonding adhesive between the upper facing and the core and using a0.020 inch (0.50 mm) t
34、hick upper facing. After curing as in 3.3, removethe upper facing, observe the degree of fill of the splice, and measurethe sag of the splice adhesive from the upper face of the core. Evidenceof adherence of foam adhesive on the upper face over the entire splicearea will also constitute evidence of
35、acceptable sagging characteristics.4.5.2 Expansion Ratio for Sheet Adhesives:4.5.2.1 Cut three 2 x 2 inches (50x 50 mm) pieces of sheet adhesive and measurethe thickness of each piece at each corner and at the center to thenearest 0.01 inch (0.25 mm).4.5.2.2 Place the specimens separately on a caul
36、plate which has been coveredwith a suitable parting agent to prevent adhesion of the test pieces tothe plate.4.5.2.3 Place the caul plate with the specimens in a circulating-air oven whichis at a temperature not higher than 27C (8OF) and raise thetemperature to 120C 5 (250F 10) at a rate of 2 - 3C (
37、3 - 5F)perminute Maintain the specimens at 120C 5 (250 F 10) for60 min. 5 and cool to room temperature,4.5.2.4 Measure the thickness of each specimen at each quadrant to the nearest0.01 inch (0.25 mm) and calculate the expansion ratio as follows:Expansion Ratio =Average thickness of each specimen af
38、ter cureAverage original thickness of the specimen4.5.3 Expansion Ratio for Paste Adhesives:4.5.3.1 Clamp a sheet of 0.100 inch (2.50 mm) thick aluminum alloy, having a 2.0.inches (50 mm) diameter hole in the center, to a caul plate. All metalsurfaces, including the inside edges of the hole, shall b
39、e covered witha suitable parting agent to prevent adhesion of the test specimen to thetool.SAE INTERNATIONAL AMS3688B Page 6 of 114.5.3.2 Extrude sufficient paste adhesive to fill the hole in the sheet. Usinga knife blade or suitable scraper, wipe across the hole to fair theadhesive flush with the u
40、pper surface of the sheet.4.5.3.3 Place the caul plate with the specimens in a circulating-air oven whichis at a temperature not higher than 27C (80 F) and raise thetemperature to 120C 5 (25OF 10) at a rate of 2 - 3 C (3 -5 F) perminute. Maintain the specimens at 120C 5 (250F 10) for 60 min. 5 and c
41、ool to room temperature.4.5.3.4 Measure the thickness of each specimen at each quadrant to the nearest0.01 inch (0.25 mm) and calculate the expansion ratio as follows:Expansion Ratio =Average thickness in in. (mm) of each specimen after cure0.10 in. (2.5 mm)4.5.4 Peak Exotherm Temperature: Shall be
42、determined on a test panel consistingof two 0.020 x 12.0 x 12.0 inches (0.50 x 300 x 300 mm) aluminum alloyfaces and a 2.00-inches (50 mm) thick, 3/16-inch (4.8-mm) cell sizenonmetallic core as shown in Figure 1. The core shall be spliced in thecenter of the panel. A suitable thermocouple shall be i
43、nserted in theapproximate geometric center of the splice. The panel shall be cured asspecified in 3.3. The maximum temperature of the thermocouple during cureof the test panel shall be reported.4.5.5 Density of Cured Adhesive:4.5.5.1 Measure the width and length or the diameter of the cured specimen
44、s usedin the expansion ratio determinations (4.5.3) to the nearest 0.01 inch(0.25 mm).4.5.5.2 Weigh each specimen to the nearest milligram.4.5.5.3 Using the average thickness of each specimen obtained during theexpansion ratio determination, calculate the density of the curedadhesive as follows:Dens
45、ity, lb/cu ft3= x 3.81Volume, cu in.Density, kg/m3=Weight, g3x 1000Volume, cmWeight, gSAE INTERNATIONAL AMS3688B Page 7 of 114.5.6 Beam Shear Strength:4.5.6.1 Specimen Preparation: Test panels shall be prepared using 0.125 inch(3.18 mm) thick AMS 4037, or equivalent, aluminum alloy sheet facingsand
46、0.625 inch (15.88 mm) thick 7.9-l/4-40 (5052) T aluminum alloyhoneycomb core conforming to AMS 4348 or to MIL-C-7438. Butting of coresections and splice locations shall be as shown in Figure 2. Testpanels shall be bonded using a face-to-core adhesive conforming toMIL-A-25463, Type I, suitable for cu
47、ring at 120C (250F). Test panelsshall be cured in accordance with 3.3 using a pressure of 50 psi 5(345 kPa 35).4.5.6.2 Beam shear testing shall be conducted as specified in MIL-C-7438 forflexural shear. Tests shall be conducted at the temperature specifiedin 3.3.2.2 within lC(2F) after not less than
48、 10 min. at the testtemperature as verified by a thermocouple attached to the specimen inthe splice material.4.6 Reports:4.6.1 The vendor of adhesive shall furnish with each shipment a report showingthe results of tests to determine conformance to the acceptance testrequirements of this specificatio
49、n and stating that the adhesive conformsto the other technical requirements of this specification. The reportshall include the purchase order number, AMS 36888, vendors materialdesignation, lot number, date of manufacture, form, and quantity. Fortwo-part paste adhesives, it shall also include the manufacturersrecommended time and temperature storage cond
