ASTM D6412-99(R2020) pdf free download

ASTM D6412-99(R2020) pdf free download.Standard Specification for Epoxy (Flexible) Adhesive For Bonding Metallic And Nonmetallic Materials
1. Scope
1.1 The specification covers a two-part modified epoxy paste adhesive for bonding metallic and nonmetallic materials. The adhesive should be suitable for forming bonds that can withstand environmental exposure to temperatures from –184 to 82 °C [–300 to 180 °F] when exposed to an expected combination of stress, temperature, and relative humidity to be encountered in service. N OTE 1—When coordinated through the Department of Defense (DoD) and the National Aeronautics and Space Administration (NASA), this practice will be a direct replacement of MIL-A-82720 (OS), MIS-26872, and MSFC-SPEC-2037. 1.2 The values stated in SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification. 1.3 The following precautionary statement pertains to the test method portion only, Section 8, of this specification: This standard does not purport to address all ofthe safety concerns, ifany, associated with its use. It is the responsibility ofthe user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
7. Test Requirements
7.1 Material—The adhesive shall be thermosetting and, when tested using the tests described in Section 8 shall meet the strength requirements of this specification. The adhesive shall not have a detrimental effect on the surfaces being bonded over the range of temperatures at which the adhesives will be used. 7.2 Qualification—The adhesive shall be qualified at the time for opening of bids. The qualification shall only apply to the formulation on which the qualification tests have been made (see 6.2). Any changes by the manufacturer in formula- tion or in the method of manufacturing, shall be cause of designating the adhesive as a new product. 7.3 Processing—Methods of specimen surface preparation, that is, cleaning and etching adherends, cure time, temperature and pressure shall be in accordance with the manufacturer’s recommendation. 7.4 The physical, mechanical and outgassing properties of the adhesive shall meet the requirements specified in Table 1. Although, it is not listed in Table 1, Type II materials shall meet the same requirements as Type I materials.
8. Test Methods
8.1 Qualification Tests—For qualification, the adhesive shall be tested using the tests described in this section. Test methods and requirements are included in Table 1. 8.2 Preparation ofTest Specimens: 8.2.1 Tensile Shear: 8.2.1.1 Adherend—The metal bonded shall be 6061-T6 or 2024-T3 aluminum alloy. N OTE 3—The use of steel substrates for the evaluation and lot acceptance of the material is optional at the discretion of the procuring agency. Use Specification A109/A109M Grade 2 Steel or Specification A167, Type 302 corrosion resistant steel. 8.2.1.2 Surface Treatment—Adherend surfaces shall be cleaned and etched in accordance with Guide D2651. 8.2.1.3 Cure—Cure time, temperature and pressure shall be in accordance with the adhesive manufacturer’s recommenda- tion.N OTE 4—Test panels or specimens, or both, other than the breakaway type shall be cut in such a manner that minimum vibration or heat is generated during the cutting operation. N OTE 5—Adhesive bondline thickness for tensile shear specimens shall be 0.05 to 0.13 mm [0.002 in. to 0.005 in.] and 0.25 to 0.43 mm [0.010 to 0.017 in.] for T-Peel specimens. Control of bondline thickness shall be accomplished by placing two lengths of appropriate diameter stainless wire [0.13 mm for tensile shear and 0.43 mm for T-Peel] in the lengthwise direction on the specimen bond area during the adhesive bonding operation; the use of the same diameter glass beads approximately 0.5 % by weight, thoroughly mixed in the adhesive may also be used to maintain uniform bondine thickness. 8.2.2 Hardness specimens shall be prepared using a mixture of resin and catalyst for Type I Grades 1 or 2 in the ratios specified by the manufacturer or Type II premixed. Pour the thoroughly mixed material into an aluminum foil cup approxi- mately 7.6 cm [3.0 in.] in diameter to a minimum thickness of 6.3 mm [0.25 in.]; cure per manufacturer’s recommendation.