1、Designation: D 6905 03 (Reapproved 2008)Standard Test Method forImpact Flexibility of Organic Coatings1This standard is issued under the fixed designation D 6905; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure for determining theability of a coating film and its substrate to resist shattering,cracki
3、ng, or chipping when the film and substrate are distendedbeyond their original form by impact.1.2 This test method does not measure impact resistance butuses rapid impact to improve Test Methods D 522, another testmethod for flexibility. Since the impact of the coating is almostinstantaneous, all of
4、 the problems associated with time vari-ables in the mandrel tests are eliminated.1.3 This test method is similar in content but not technicallyequivalent to Test Method D 2794.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonl
5、y.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced
6、 Documents2.1 ASTM Standards:2D 522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD 609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD 823 Practices for Producing Films of Uniform Thicknessof Paint, Va
7、rnish, and Related Products on Test PanelsD 1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base3D 1400 Test Method for Nondestructive Measurement ofDry Film Thickness of Nonconductive CoatingsApplied toa Nonferrous Metal Base3D 2240
8、Test Method for Rubber PropertyDurometerHardnessD 2794 Test Method for Resistance of Organic Coatings tothe Effects of Rapid Deformation (Impact)3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 impact flexibility, nof a coating, the percent areaincrease required to produce crac
9、king in the deformed coating.4. Summary of Test Method4.1 The organic coating under test is applied to suitable thinmetal panels. After the coating has cured, a standard weight/indenter is dropped from a measured distance so as to strike thesubstrate which deforms the coating and the substrate. Thep
10、ercent elongation is the highest area of distensibility in whichthere is no film breaks that the film can stand.5. Significance and Use5.1 Coatings attached to substrates are subjected to damag-ing impacts during the manufacture of articles and their use inservice. This impact resistance test method
11、 has been found tobe useful in predicting the performance of organic coatings fortheir ability to resist cracking caused by impacts.6. Apparatus6.1 Impact Flexibility Tester4, assembly illustrated in Figs.1 and 2. The instrument contains a 1.63 kg (3.6 lb) weight/indenter, a rubber pad and an alumin
12、um pad, Fig. 3. The roundrod weight/indenters two spherical ends (Marked “A” and“B”) are shown in Figs. 4 and 5. The dimensions for theSpherical weight/indenter are shown in Table 1. The rod slidesin a vertical, slotted guide and serves as a falling weight toimpact a test panel with the “ embossed”
13、end. When positionedproperly, the lifting knob on the weight/indenter coincides withthe bottom of the guide tube.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.23 on Physi
14、cal Properties of Applied Paint Films.Current edition approved July 1, 2008. Published July 2008. Originally approvedin 2003. Last previous edition approved in 2003 as D 6905 - 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org
15、. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4The sole source of supply of the apparatus known to the committee at this timeis the IM-172-GE Impact Tester, available from the Paul N. Gardner Company, Inc.,316 N.E. F
16、irst Street, Pompano Beach, FL 33060. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.1Copyright ASTM International,
17、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Test Specimens7.1 Apply uniform coatings of the material to be tested tometal panels treated as specified. Prepare a minimum of fourcoated panels for the material.NOTE 1The coatings should be applied in accordance
18、 with PracticesD 823, or as agreed upon between the producer and the user.7.2 Cure the coated panels under conditions of humidity andtemperature agreed upon between the producer and the user.NOTE 2The thickness of the dry coatings should be measured inaccordance with Test Methods D 1186, Test Method
19、 D 1400 or any othertest method as agreed upon between the producer and the user.8. Conditioning8.1 Unless otherwise agreed upon between the producer andthe user, condition the coated test panels for at least 24 h at 236 2C (73.5 6 3.5F) and 50 6 5 % relative humidity.Conduct the test in the same en
20、vironment or immediately onremoval therefrom.9. Procedure9.1 Install the weight/indenter having the specific heads intothe slotted guide tube. Install the aluminum plate with the toprubber anvil head in place on the base. This rubber anvil has aShore A hardness of 60 6 5. Determine hardness in accor
21、dwith Test Method D 2240. Replace rubber anvil if outsidehardness specifications or if worn or damaged.9.2 With an uncoated panel in place on the rubber anvil,determine the height of drop for each end of the weight/indenter to show on the panel slight evenly spaced segmentmarks of the weight/indente
22、r circumference. The heights sodetermined will always be used.9.3 Place the coated panel to be tested face down against therubber anvil and drop the weight/indenter from the determinedheight onto the panel so that the impression of the entire rim ofthe weight/indenter is made on the panel surface.9.
23、4 Remove the panel from the tester after the first bounce.9.5 Replace the coated panel to be tested face down againstthe rubber anvil, reverse the weight/indenter and drop theweight/indenter from the above determined height.9.6 Remove the panel from the tester after the first impact.9.7 Using the na
24、ked eye or magnification, as agreed uponbetween the producer and the user, visually inspect the impactcoating area to detect fine surface cracking and record themaximum percent elongation, that is, the area increase accom-modated by the coating without cracking or other failure, usingvalues in Table
25、 1.10. Report10.1 Report the following for each coating tested:10.1.1 The maximum percent elongation or flexibilitywhich the film will stand,10.1.2 Height the weight/indenter was raised from the panelsurface,10.1.3 Thickness of coating,10.1.4 Substrate thickness and type of metal,10.1.5 Method of pa
26、nel preparation, and10.1.6 Atmospheric conditions under which the coated pan-els were conditioned and tested.11. Precision and Bias11.1 PrecisionThe precision of the procedure in TestMethod D 6905 for measuring flexibility is being determined.11.2 BiasSince there is no accepted reference materialsui
27、table for determining the bias for the procedure in this testmethod, bias cannot be determined.FIG. 1 Full View Impact Flexibility TesterFIG. 2 Base View Impact Flexibility TesterD 6905 03 (2008)212. Keywords12.1 cracking failure; extrusion indentation; impact failure;intrusion indentationASTM Inter
28、national takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely
29、their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand shou
30、ld be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Stan
31、dards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-
32、832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 3 Intregal Indenter, Rubber Pad, Aluminum BaseFIG. 4 Indenter End “A”FIG. 5 Indenter EndTABLE 1 Table of Percent Area IncreaseSphericalSegmentEndBaseDiameter,mm (in.)SegmentRadius,mm (in
33、.)SegmentElevation,mm (in.)%AreaIncrease1 A 9.5 (0.375) 4.85 (0.194) 3.65 (0.146) 602 A 9.5 (0.375) 5.20 (0.208) 2.98 (0.119) 403 A 9.5 (0.375) 6.30 (0.252) 2.10 (0.084) 204 A 9.5 (0.375) 8.15 (0.326) 1.48 (0.059) 105 B 9.5 (0.375) 11.0 (0.440) 1.05 (0.042) 56 B 9.5 (0.375) 16.9 (0.676) 0.68 (0.027) 27 B 9.5 (0.375) 23.7 (0.947) 0.48 (0.019) 18 B 9.5 (0.375) 33.3 (1.332) 0.32 (0.013) 0.5D 6905 03 (2008)3
