1、Designation: B 680 80 (Reapproved 2004)Standard Test Method forSeal Quality of Anodic Coatings on Aluminum by AcidDissolution1This standard is issued under the fixed designation B 680; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a test for the quality of seal ofporous anodic coatings on aluminum and its all
3、oys. It is basedupon the loss in mass of the coating after immersion in a warmphosphoric-chromic acid solution.1.2 This test method is applicable to anodic coatings in-tended for exposure to the weather, or for protective purposesin corrosive media, and where resistance to staining is impor-tant.1.3
4、 This test method is not applicable to:1.3.1 Hard coatings, which normally are not sealed.1.3.2 Anodic coatings that have been sealed only in dichro-mate solutions.1.3.3 Anodic coatings that have undergone a treatment torender them hydrophobic.1.4 This standard does not purport to address all of the
5、safety 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 Documents2.1 ASTM Standards:2B 137 Test Method for Measur
6、ement of Coating Mass PerUnit Area on Anodically Coated AluminumD 1193 Specification for Reagent Water2.2 International Standard:ISO 3210 Anodizing of Aluminum and Its AlloysAssessment of Sealing Quality by Measurement of theLoss of Mass After Immersion in Phosphoric-ChromicAcid Solution33. Signific
7、ance and Use3.1 This test method describes a destructive test procedurefor measuring the degree of seal of the porosity in anodic oxidecoatings. Low coating mass loss is an indication of good sealquality and of the ability of the coating to resist staining and“blooming” in many types of service.3.2
8、This test method is suitable for quality control purposeswithin manufacturing operations and for determining whetheranodized parts meet seal quality requirements in applicablespecifications.4. Apparatus4.1 Laboratory Balance, accurate to 1 mg.4.2 Glass Container, means of heating and stirring, and a
9、thermometer. There shall be no metal in contact with the testspecimen or the solution.5. Acid Test Solution5.1 The test solution shall have the following makeup:Chromic acid anhydride (CrO3)206 0.5 gOrthophosphoric acid of 85 mass %, density 1.69 35 6 0.5 mLDistilled or deionized water conforming wi
10、th Type IIIReagent Water of Specification D 1193, to makeup to1000 mLNOTE 1This solution is commonly referred to as a “stripping solu-tion” for anodic coatings and is of the same composition as that employedin Test Method B 137. This solution dissolves the anodic coating with nosignificant attack of
11、 the substrate metal.5.2 The test solution may be used repeatedly but shall bediscarded after1gofanodic coating has been dissolved perlitre of solution.NOTE 2The solution may be used for as many as 20 test specimensper litre provided that the average mass loss does not exceed 50 mg perspecimen.6. Pr
12、eparation of Test Specimen6.1 Select an uncontaminated specimen having an areaabout 1 dm2of the anodized surface to be tested.6.2 The mass of the specimen shall not exceed 200 g.1This test method is under the jurisdiction of ASTM Committee B08 on Metallicand Inorganic Coatings and is the direct resp
13、onsibility of Subcommittee B08.07 onChromate Conversion Coatings.Current edition approved Oct. 1, 2004. Published October 2004. Originallyapproved in 1980. Last previous edition approved in 2000 as B 680 80 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C
14、ustomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr
15、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 When it is desired to conduct the test on one face onlyof the specimen, the anodic coating on the other surface isremoved by a chemical or mechanical process, leaving thesignificant face intact.6.4 Bare, cut edges and oth
16、er uncoated surfaces of thespecimen shall be left bare and shall not be given a protectivecoating.7. Procedure7.1 Measure the area (A) in square decimetres of the coatingwithout including cut edges or other uncoated surfaces.7.2 Weigh the specimen to the nearest 1 mg ( W1).7.3 Immerse the specimen f
17、or 15 6 0.1 min in the stirredacid test solution maintained at a temperature of 38 6 1C.7.4 Remove the specimen and wash thoroughly in deionizedor distilled water conforming with Type III reagent water ofSpecification D 1193.7.5 Dry the specimen with clean compressed air, or allow itto air-dry.7.6 R
18、eweigh the specimen to the nearest 1 mg (W2).7.7 When it is desired to express the mass loss in the test asa percent of the total coating mass, use the above procedurefollowed by stripping the remainder of the oxide in thephosphoric-chromic acid solution in accordance with TestMethod B 137.7.8 Rinse
19、 and dry the specimen as above and reweigh it tothe nearest 1 mg (W3).8. Report8.1 Report the mass loss per square decimetre calculated asfollows:Mass Loss, mg/dm25W12 W2!A(1)8.2 When required, report the mass loss in the test as apercent of the total coating mass, calculated as follows:Coating Diss
20、olved in Test, % 5W12 W2W12 W33 100 (2)9. Precision and Bias9.1 The precision and accuracy of coating mass loss per unitarea are most affected by the accuracy of measurement of thearea of the anodized surface. When smooth, flat rectangular testspecimens of sheet are used, the reproducibility of test
21、 resultsamong experienced operators is usually within 62 mg/dm2,or610 % of the arithmetic mean of the test values, whichever isgreater.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this stand
22、ard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are 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 andi
23、f not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, wh
24、ich 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 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).B 680 80 (2004)2
