1、Designation: F7 95 (Reapproved 2011)Standard Specification forAluminum Oxide Powder1This standard is issued under the fixed designation F7; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in parent
2、heses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers aluminum oxide (alumina)powder in two classes of particle size, two chemical grades,and two levels of acidity, for use as an in
3、sulating coating or asan ingredient of ceramic mixtures for components of electronicdevices as follows:1.1.1 Particle Sizes:1.1.1.1 Class AParticle size No. 500 nominal mesh(nominal average particle size = 24.3 m).1.1.1.2 Class BParticle size No. 900 nominal mesh(nominal average particle size = 1.7
4、m).1.1.2 Chemical GradesGrades 1 and 2 as specified underchemical requirements in Section 3.1.1.3 Acidity Levels: pH (acid) 4.5 to 6.5 and pH (neutral)6.5 to 7.5.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 The follow
5、ing safety hazards caveat pertains only to thetest methods in this specification. This standard does notpurport to address all of the safety concerns, if any, associatedwith its use. It is the responsibility of the user of this standardto establish appropriate safety and health practices anddetermin
6、e the applicability of regulatory limitations prior touse.2. Referenced Documents2.1 ASTM Standards:2C183 Practice for Sampling and the Amount of Testing ofHydraulic CementE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3. Chemical Composition3.1 For a specified particle size and
7、level of acidity, thealuminum oxide shall conform to the requirements of Table 1as to chemical composition.4. Physical Properties4.1 The alumina shall be “chalk white,” dry, free fromlumps, and of particle size distribution as agreed upon betweenpurchaser and seller.5. Sampling5.1 Each lot of alumin
8、a shall be properly sampled inaccordance with standard techniques, such as Practice C183.6. Test Methods6.1 Water-Soluble Content:6.1.1 ProcedureDetermine the total water-soluble contentby measuring the electrical conductivity of a 100-mL distilledor deionized water extract from a 5-g sample of alum
9、ina.Elutriate by vigorously shaking the alumina suspension in aflask for 1 to 2 min, allowing the solids to settle and decantingthe clear supernatant liquid after 60 min. Measure the conduc-tivity of the liquid with a standard cell and bridge. Correct thismeasurement for the “blank” reading on a sim
10、ilarly treatedequal volume of the same pure water. Convert the net increasein conductivity of the water extract first to parts of water-soluble content as sodium chloride (NaCl) per million parts ofwater (factor is 1 micromho = 0.5 ppm NaCl), then relate to theactual weight of elutriated alumina. Fo
11、r example, on a typical100-mL extract 10 micromhos (net) or 5 parts of NaCl permillion of water in this volume of liquid is equivalent to 100parts of NaCl per million of alumina on the basis of a 5-gsample.1This specification is under the jurisdiction of ASTM Committee F01 onElectronics and is the d
12、irect responsibility of Subcommittee F01.03 on MetallicMaterials.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 1958. Last previous edition approved in 2006 as F7 95 (2006). DOI:10.1520/F0007-95R11.2For referenced ASTM standards, visit the ASTM website, www.astm.or
13、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume 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.6.1.2 Calcula
14、tion Determine the parts per million ofwater-soluble content as follows:ppm 5 107KcRb2 Rx! /RbRx (1)where:Kc= cell constant, cm1,Rb= specific resistance of test water, Vcm, andRx= specific resistance of alumina extract in test water,Vcm.6.2 Particle Size:6.2.1 Determine particle size distribution by
15、 any of thefollowing methods: (a) Coulter counter, (b) M.S.A. centrifugemethod, (c) Cahn Sedimentometer, or (d) Sharples Micromero-graph.NOTE 1Procedures for determining particle size by the methodsshown in Table 2 are described in the operating manuals of the equipmentlisted.6.2.2 Number average pa
16、rticle size may be taken as the50 % point on the particle size distribution curve or may bemeasured by the Fisher sub-sieve sizer.6.2.3 A density of 3.97 g/cm3for aluminum oxide will beused in all calculations.6.2.4 Particle size distribution of acceptable material in bothClass A and Class B will be
17、 by agreement between purchaserand seller. Sample size and method of dispersion will beidentical in all test correlations, as specified in Table 2. Typicalresults are shown in Table 3.6.2.5 Number average particle size of acceptable material inboth Class A and Class B will be by agreement betweenpur
18、chaser and seller.6.2.6 Complete dispersion of samples is essential and rec-ommended procedure in Table 2 shall be followed.6.3 Hydrogen-Ion Concentration (pH):6.3.1 Weigh out 20 g of the sample and transfer to a clean100-mL beaker. Add 20 mL of distilled or deionized water andmake into a slurry usi
19、ng a clean stirring rod. Stir for 1 to 2 min.Wash electrodes thoroughly with distilled or deionized water,remix slurry, immerse electrodes into slurry approximately 6 to12 mm, and measure pH in accordance with Test Method E70.6.3.2 Any weight of slurry in the above ratio may be usedprovided there is
20、 sufficient slurry to immerse electrodes to theproper depth.6.3.3 Wash electrodes immediately after using with severalhundred millilitres of distilled or deionized water, removing theadhered slurry with the aid of a pipe cleaner. It is important foraccuracy to prevent buildup of the slurry on the el
21、ectrodes.7. Keywords7.1 alumina; particle sizing methods; powderTABLE 1 Chemical RequirementsElement or CompoundComposition, %Grade 1 Grade 2Alumina (Al2O3), min 99.65 99.65Silica (SiO2), max 0.03 0.12Magnesia (MgO), max 0.02 0.01Ferric oxide (Fe2O3), max 0.04 0.04Total alkali (as Na2O), max 0.04 0.
22、04Carbon (C), max 0.01 0.01Calcium oxide (CaO), max 0.02 0.01Zirconium oxide (ZrO2), max 0.01 0.01Boron (B), max 0.001 0.002Gallium oxide (Ga2O3), max 0.3No other single metallic impurityto exceed0.02 0.02Composition, ppmWater-soluble matter (as NaCl), max 300 300F7 95 (2011)2TABLE 2 Requirements fo
23、r Sample Sizes and Dispersing AgentsMethodSampleSize, gSampleConcentrationWeight%DispersingMediumDispersing AgentCoulter counterA0.25 0.1 methanol LiCl-38g/galM.S.A. centrifuge 1.0 0.03 H2ONa2SiO3to pH = 10.5Cahn Sedimentometer 0.4 0.03 H2O 0.1 % Na2P4O7Sharples Micromerograph 0.06 N2noneAThe instru
24、ment manufacturer recommends the following: sample size0.0025 g, sample concentration0.001 weight%,dispersing medium0.9 % NaCl in H2O,and dispersing agent0.1 % Na2P4O7.F7 95 (2011)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item
25、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 standard is subject to revision at any time by the responsible technical commit
26、tee 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 Headquarters. Your comments will receive careful consideration at a mee
27、ting 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.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive,
28、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).
29、 Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 3 50 % Point Results of Particle Size DistributionAnalysis on Typical MaterialDiameter in MicrometersA , BMethodMaterial (ClassGrade)A-1 A-2 B-1 B-2Sharples Micromerograph 13.2 6.2 5.1 4.8Cahn Sedimentometer 15.5 7.0 4.7 4.7M.S.A. centrifuge 14.0 7.1 4.2 4.2Coulter counter 17.1 8.1 6.6 5.2AFrom Subcommittee I round-robin test resultsNov. 8, 1967.BVariations between laboratories should not exceed 3 % on similar instruments. Editorally corrected.F7 95 (2011)4
