1、Designation: B 680 80 (Reapproved 2009)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 () 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 allo
3、ys. 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 The values stated in SI units are to be regarded asst
5、andard. No other units of measurement are included in thisstandard.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 ap
6、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 137 Test Method for Measurement of Coating Mass PerUnit Area on Anodically Coated AluminumD 1193 Specification for Reagent Water3. Significance and Use3.1 This test method describes a destructive test pr
7、ocedurefor 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 This test method is suitable for quality control purposeswithin
8、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 athermometer. There shall be no metal in contact with the testspe
9、cimen 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 with Type IIIReagent Water of Specification D 1193, to makeup to10
10、00 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 the substrate metal.5.2 The test solution may be used repeatedl
11、y 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. Preparation of Test Specimen6.1 Select an uncontaminated specimen
12、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 ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.07 onConversion Coatings.Current e
13、dition approved April 15, 2009. Published June 2009. Originallyapproved in 1980. Last previous edition approved in 2004 as B 680 80 (2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
14、 information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr 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
15、 surface isremoved by a chemical or mechanical process, leaving thesignificant face intact.6.4 Bare, cut edges and other 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 incl
16、uding cut edges or other uncoated surfaces.7.2 Weigh the specimen to the nearest 1 mg ( W1).7.3 Immerse the specimen for 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 Typ
17、e III reagent water ofSpecification D 1193.7.5 Dry the specimen with clean compressed air, or allow itto air-dry.7.6 Reweigh 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 str
18、ipping the remainder of the oxide in thephosphoric-chromic acid solution in accordance with TestMethod B 137.7.8 Rinse 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 Whe
19、n required, report the mass loss in the test as apercent of the total coating mass, calculated as follows:Coating Dissolved 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 thear
20、ea of the anodized surface. When smooth, flat rectangular testspecimens of sheet are used, the reproducibility of test 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
21、 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 their own responsibility.This standar
22、d 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 should be addressed to ASTM International
23、 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 Standards, at the address shown below.Thi
24、s 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 (2009)2
