1、Designation:C92509(Reapproved 2014)Standard Guide forPrecision Electroformed Wet Sieve Analysis of NonplasticCeramic Powders1This standard is issued under the fixed designation C925;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the
2、 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.Scope*1.1 This guide covers the determination of the particle sizedistribution of pulverized alumina and quartz for particl
3、e sizesfrom 45 to 5 m by wet sieving.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.2.1 The only exception is in the Section 5,Apparatus,5.1where there is no relevant SI equivalent.1.3 This standard does not purport to add
4、ress the safetyconcerns associated with its use.It is the responsibility of theuser of this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Referenced Documents2.1 ASTM Standards:2E161 Specification for Precision
5、Electroformed Sieves3.Summary of Guide3.1 A separate dispersed suspension of the powder is wetsieved through each sieve,using vacuum and vibration.Thesieve and sample are dried and weighed.4.Significance and Use4.1 Both suppliers and users of pulverized ceramic powderswill find this test method usef
6、ul to determine particle sizedistributions for materials specifications,manufacturingcontrol,development,and research.4.2 The test method is simple,although tedious,usesinexpensive equipment,and will provide a continuous curvewith data obtained with standardized woven sieves.5.Apparatus5.1 Precision
7、 Electroformed Sieves,3-in.,mounted in brassframes,having nominal apertures of 45,30,20,10,and 5 mand a support grid having 5.7 lines per centimetre.Intermediatesizes may also be used.5.2 Sieving Device(Fig.1):5.2.1 Filtering Flask(suction flask),1-L,with side arm,5.2.2 Bchner Funnel(for example,Coo
8、rs No.2),5.2.3 O-Ring,7.5-cm,rubber,5.2.4 Graduate,1-L,5.2.5 Rubber Stoppers,one-hole to fit the flask and thefunnel,two-hole to fit the graduate,5.2.6 Quantity of glass tubing and rubber tubing,5.2.7 Metal Rod,15 to 20-cm,about 5 mm in diameter,and,5.2.8 Vacuum Source.5.3 Ultrasonic Cleaner,require
9、d to clean all sieves below20 m.It should be low-powered(for example,100 W).5.4 Analytical Balance,capable of weighing up to 100 g andhaving at least three significant digits after the decimal.5.5 Drying Oven,capable of maintaining 110 6 5C.5.6 Desiccator,containing magnesium perchlorate or othersui
10、table desiccant.6.Reagents and Materials6.1 Water,visually clear and particle free,not necessarilydistilled,at room temperature or slightly above.6.2 Sieving Solution,a dispersing media consisting of 0.1weight%solution of sodium hexametaphosphate or sodiumpyrophosphate in water.6.3 Drying Agents,ace
11、tone or methyl alcohol,commercialgrade.7.Sampling7.1 Since the amount of sample used in the determination isquite small,great care must be taken to avoid segregation.Gross samples must be cut down very carefully using splitters,rifflers,or simple cone and quartering techniques.Adjusting theportion t
12、o an exact weight must be avoided.That is,arepresentative portion must be extracted from the analyticalsample and all of it weighed and used.1This guide is under the jurisdiction of ASTM Committee C21 on CeramicWhitewares and Related Productsand is the direct responsibility of SubcommitteeC21.04 on
13、Raw Materials.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1979.Last previous edition approved in 2009 as C925 09.DOI:10.1520/C0925-09R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Ann
14、ual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.Preparation of
15、 Apparatus8.1 Cleaning of SievesUse sufficient sieving solution tocover the sieve when suspended near the bottom of theultrasonic tank.(Some organic liquids are better but create adefinite explosion hazard.)Turn on the generator for about 30s.Fine sieves may need multiple treatments.(Exposure toultr
16、asonic energy for periods exceeding 30 s at one time maydamage the sieves.)After each cleaning carefully examine thesieve against a light,using a magnifying glass,for blockagesand breaks.(Breaks can be repaired with epoxy resin.)Sievesof 20 m and finer should be cleaned after each analysis.Rinsein clear water and dry at 110C.8.2 Collector and Vacuum ControlAssemble apparatus asshown in Fig.1.9.Calibration and Standardization9.1 Calibration of SievesThis must be done for highlyaccurate analyses o
