1、Designation: F 7 95 (Reapproved 2006)Standard Specification forAluminum Oxide Powder1This standard is issued under the fixed designation F 7; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in pare
2、ntheses indicates the year of last reapproval.Asuperscriptepsilon (e) 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
3、 insulating 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
4、.7 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 following safety hazards caveat pertains only to thetest methods in this specification. This standard does notpurport to addres
5、s 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 anddetermine the applicability of regulatory limitations prior touse.2. Referenced Documents2.1 ASTM Standards:2C 183 Practice for S
6、ampling 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 level of acidity, thealuminum oxide shall conform to the requirements of Table 1as to chemical composition.4. Physical P
7、roperties4.1 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 alumina shall be properly sampled inaccordance with standard techniques, such as Practice C 183.6. Test Methods6.1 Water-Solub
8、le 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 alumina.Elutriate by vigorously shaking the alumina suspension in aflask for 1 to 2 min, allowing the solids to settle and
9、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 similarly treatedequal volume of the same pure water. Convert the net increasein conductivity of the water extract first t
10、o 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. For example, on a typical100-mL extract 10 micromhos (net) or 5 parts of NaCl permillion of water in this volume of liqui
11、d 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 F1 onElectronics and is the direct responsibility of Subcommittee F01.03 on MetallicMaterials.Current edition approved Jan. 1, 2006. Published Januar
12、y 2006. Originallyapproved in 1958 as F758T. Last previous edition approved in 2000 asF795(2000).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 Docum
13、ent Summary page onthe ASTM website.TABLE 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 0.04Carbon (C), max 0.01 0.01C
14、alcium 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 3001Copyright ASTM International, 100 Barr Harbor Drive, PO Box C70
15、0, West Conshohocken, PA 19428-2959, United States.6.1.2 Calculation 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
16、.6.2 Particle Size:6.2.1 Determine particle size distribution by any of thefollowing methods: (a) Coulter counter, (b) M.S.A. centrifugemethod, (c) Cahn Sedimentometer, or (d) Sharples Micromer-ograph.NOTE 1Procedures for determining particle size by the methodsshown in Table 2 are described in the
17、operating manuals of the equipmentlisted.6.2.2 Number average particle 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 distri
18、bution of acceptable material in bothClass A and Class B will be 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 mat
19、erial inboth Class A and Class B will be by agreement betweenpurchaser 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、 20 mL of distilled or deionized water andmake into a slurry using 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
21、weight of slurry in the above ratio may be usedprovided there is 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
22、important foraccuracy to prevent buildup of the slurry on the electrodes.7. Keywords7.1 alumina; particle sizing methods; powderASTM 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
23、 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 andif not r
24、evised, 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, which you
25、 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
26、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).TABLE 2 Requirements for Sample Sizes and Dispersing
27、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 instrument manufacturer recommends t
28、he following: sample size0.0025 g, sample concentration0.001 weight%,dispersing medium0.9 % NaCl in H2O,and dispersing agent0.1 % Na2P4O7.TABLE 3 50 % Point Results of Particle Size DistributionAnalysis on Typical MaterialDiameter in MicrometersA , BMethodMaterial (ClassGrade)A-1 A-2 B-1 B-2Sharples
29、 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.F 7 95 (2006)2
