1、Designation: F 21 65 (Reapproved 2007)Standard Test Method forHydrophobic Surface Films by the Atomizer Test1This standard is issued under the fixed designation F 21; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the detection of the presence ofhydrophobic (nonwetting) films on surfaces and the presenceof hyd
3、rophobic organic materials in processing ambients.When properly conducted, the test will enable detection offractional molecular layers of hydrophobic organic contami-nants. On very rough or porous surfaces the sensitivity of thetest may be significantly decreased.1.2 The values stated in inch-pound
4、 units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 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
5、 practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 351 Classification for Natural Muscovite Block Mica andThins Based on Visual Quality3. Terminology3.1 Definitions:3.1.1 hydrophilichaving a strong affinity for water; wet-t
6、able.3.1.2 hydrophobichaving little affinity for water; nonwet-table.4. Summary of Test Method4.1 The atomizer test3is performed by subjecting the drysurface to be tested to a fine water spray. The interpretation ofthe test is based upon the pattern of wetting. In the absence ofhydrophobic films, th
7、e impinging water droplets will wet thesurface and spread immediately to form a continuous waterfilm. In areas where hydrophobic materials are present on thesurface, the sprayed droplets will not wet the surface andspread but will tend to remain as fine droplets.5. Significance and Use5.1 The atomiz
8、er test as described in this test method isnondestructive and may be used for control and evaluation ofprocesses for the removal of hydrophobic contaminants. Thetest may also be used for the detection and control ofhydrophobic contaminants in processing ambients. For thisapplication, a surface free
9、of hydrophobic films is exposed tothe ambient and subsequently tested.46. Interferences6.1 Loss of sensitivity may result from either of the follow-ing factors:6.1.1 The presence of hydrophilic substances on the surfaceto be tested, test equipment, or test materials, or6.1.2 An unusually rough or po
10、rous surface condition.7. Apparatus7.1 Spray Gun Atomizer.57.2 Low Power Microscope (53 to 503), and light sourcefor observation of small piece parts.8. Reagents and Materials8.1 Acetone, reagent grade.8.2 Mica Blanks, preferably 1 in. (25 mm) by 2 in. (50 mm)by 0.015 in. (0.38 mm) or larger, having
11、 a minimum ASTMquality V6 as described in Classification D 351.8.3 Oleic or Stearic AcidA 0.005 to 0.05% solution inacetone.8.4 OxygenFiltered low-pressure (15 psi min) oxygen orother suitable gas that is free of hydrophobic and hydrophilicsubstances.NOTE 1The freedom of the water and the gas from h
12、ydrophobic andhydrophilic contamination may be determined in accordance with Section9.1This test method is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition appr
13、oved April 1, 2007. Published April 2007. Originallyapproved in 1962. Last previous edition approved in 2002 as F 21 65(2002).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,
14、 refer to the standards Document Summary page onthe ASTM website.3Linford, H. B., and Saubestre, E. B., “A New Degreasing Evaluation Test: TheAtomizer Test,” ASTM Bulletin, May 1953, p. 47.4Feder, D. O., and Koontz, D. E., “Detection, Removal and Control of OrganicContaminants in the Production of E
15、lectron Devices,” ASTM STP 246, Am. Soc.Testing Mats., p. 40 (1959).5PaascheAir Brush Model VL-1 or its equivalent has been found satisfactory forthis purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8.5 WaterDeionized or dist
16、illed water is preferred. Waterof higher ionic content may render the test destructive. Thewater used must be free of hydrophobic and hydrophilicsubstances (see Note 1).9. Calibration and Standardization9.1 The degree of freedom of the test equipment andmaterials from hydrophobic contamination is pr
17、oportional tothe number of alternate spraying and drying cycles required toproduce detectable hydrophobic contamination on a freshlycleaved mica surface. This test may be performed with greatersensitivity by masking a portion of the freshly cleaved surfaceunder test with a mica sheet (having both su
18、rfaces freshlycleaved) during the sequential test cycle. After the desirednumber of sprays, the mask shall be removed and the entiresurface retested for a detectable difference in wetting behaviorbetween the two areas.9.2 To assure that test results are not obscured by floodingor by hydrophilic cont
19、aminants, a freshly cleaved mica surfacefrom which the solvent from one drop (0.05 to 0.10 mL) of a0.005 to 0.05% solution of oleic or stearic acid in acetone hasbeen allowed to evaporate shall, when tested, clearly show thedemarkation between the clean and contaminated areas.10. Procedure10.1 Testi
20、ng of SurfacesHold the test surface 10 in. (250mm) to 20 in. (500 mm) from the atomizer and spray with afine mist of water for a period of 1 to 10 s.10.2 Testing of AmbientsExpose a freshly cleaved micasurface to the ambient and subsequently perform the test asdescribed in 10.1.NOTE 2Exposure may be
21、 by immersion of the mica surface in theambient or by deposition of a sample of the ambient on the mica surface.The procedure described in 9.1 may be used to increase the sensitivity ofthis test.11. Interpretation of Results11.1 Surfaces tested as described in 10.1 shall be consideredfree of hydroph
22、obic contaminants by this test if the impingingwater droplets spread immediately to form a thin, continuousuniform water film as shown in Fig. 1. If hydrophobiccontaminants are present, as evidenced by discontinuous ornonuniform water films, the degree of contamination may beestimated by comparison
23、of the pattern of wetting with Figs.2-5.F 21 65 (2007)2FIG. 1 Atomizer Test of Nickel Specimen with No Detectable Hydrophobic Contaminant (32 Reduced One-Half in Reproduction)FIG. 2 Atomizer Test of Nickel Specimen Showing Trace of Hydrophobic Contaminant (32, Reduced One-Half in Reproduction). Note
24、Slight Discontinuities in Otherwise Uniform Water FilmF 21 65 (2007)3FIG. 3 Atomizer Test of Nickel Specimen Showing Traces of Hydrophobic Contaminant (32, Reduced One-Half in Reproduction)FIG. 4 Atomizer Test of Partially Contaminated Nickel specimen (32, Reduced One-Half in Reproduction)F 21 65 (2
25、007)4ASTM 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
26、, 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 andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional st
27、andardsand 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 Co
28、mmittee 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).FIG. 5 Atomizer Test of Nickel Specimen with Hydrophobic Film Covering Surface (32, Reduced One-Half in Reproduction)F 21 65 (2007)5
