1、Designation: D6905 03 (Reapproved 2012)Standard Test Method forImpact Flexibility of Organic Coatings1This standard is issued under the fixed designation D6905; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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,cracking
3、, 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 D522, another testmethod for flexibility. Since the impact of the coating is almostinstantaneous, all of th
4、e 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 D2794.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.
5、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 Doc
6、uments2.1 ASTM Standards:2D522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish,
7、and Related Products on Test PanelsD1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base (Withdrawn 2006)3D1400 Test Method for Nondestructive Measurement of DryFilm Thickness of Nonconductive Coatings Applied to aNonferrous Metal Bas
8、e (Withdrawn 2006)3D2240 Test Method for Rubber PropertyDurometer Hard-nessD2794 Test Method for Resistance of Organic Coatings tothe Effects of Rapid Deformation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 areaincreas
9、e required to produce cracking 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 coati
10、ng and the substrate. Thepercent 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 imp
11、act resistance test method 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. 1and 2. The instrument contains a 1.63 kg (3.6 lb) weight/indenter,
12、a rubber pad and an aluminum 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 slides1This test method is under the jurisdiction of ASTM Committee D01 on Paintand
13、 Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Nov. 1, 2012. Published November 2012. Originallyapproved in 2003. Last previous edition approved in 2008 as D6905 03 (2008).DO
14、I: 10.1520/D6905-03R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this his
15、torical standard is referenced onwww.astm.org.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. First Street, Pompano Beach, FL 33060. If you are aware of alternativesuppliers, plea
16、se provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1i
17、n a vertical, slotted guide and serves as a falling weight toimpact a test panel with the “embossed” end. When positionedproperly, the lifting knob on the weight/indenter coincides withthe bottom of the guide tube.7. Test Specimens7.1 Apply uniform coatings of the material to be tested tometal panel
18、s treated as specified. Prepare a minimum of fourcoated panels for the material.NOTE 1The coatings should be applied in accordance with PracticesD823, 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 pr
19、oducer and the user.NOTE 2The thickness of the dry coatings should be measured inaccordance with Test Methods D1186, Test Method D1400 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
20、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 environment or immediately onremoval therefrom.9. Procedure9.1 Install the weight/indenter having the specific heads intothe slotted guide tube. Install the aluminum plate wit
21、h the toprubber anvil head in place on the base. This rubber anvil has aShore A hardness of 60 6 5. Determine hardness in accordwith Test Method D2240. 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 h
22、eight of drop for each end of the weight/indenter to show on the panel slight evenly spaced segmentmarks of the weight/indenter 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
23、determinedheight onto the panel so that the impression of the entire rim ofthe weight/indenter is made on the panel surface.9.4 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 th
24、eweight/indenter from the above determined height.9.6 Remove the panel from the tester after the first impact.9.7 Using the naked eye or magnification, as agreed uponbetween the producer and the user, visually inspect the impactcoating area to detect fine surface cracking and record themaximum perce
25、nt elongation, that is, the area increase accom-modated by the coating without cracking or other failure, usingvalues in Table 1.TABLE 1 Table of Percent Area IncreaseSphericalSegmentEndBaseDiameter,mm (in.)SegmentRadius,mm (in.)SegmentElevation,mm (in.)%AreaIncrease1 A 9.5 (0.375) 4.85 (0.194) 3.65
26、 (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)
27、 0.32 (0.013) 0.5FIG. 1 Full View Impact Flexibility TesterFIG. 2 Base View Impact Flexibility TesterD6905 03 (2012)210. 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
28、from the panelsurface,10.1.3 Thickness of coating,10.1.4 Substrate thickness and type of metal,10.1.5 Method of panel 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 TestMet
29、hod D6905 for measuring flexibility is being determined.11.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod, bias cannot be determined.12. Keywords12.1 cracking failure; extrusion indentation; impact failure;intrusion indentati
30、onASTM International 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, a
31、re entirely 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 stand
32、ardsand should 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 Commi
33、ttee on Standards, 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 aboveaddres
34、s or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. 3 Intregal Indenter, Rubber Pad, Aluminum BaseFIG. 4 Indenter End “A”FIG. 5 Indenter EndD6905 03 (2012)3
