ASTM_C_1730_-_17.pdf

Designation:C173017Standard Test Method forParticle Size Distribution of Advanced Ceramics by X-RayMonitoring of Gravity Sedimentation1This standard is issued under the fixed designation C1730;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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 the determination of particlesize distribution of advanced ceramic powders.Experience hasshown that this test method is satisfactory for the analysis ofsilicon carbide,silicon nitride,and zirconium oxide in the sizerange of 0.1 up to 50 m.1.1.1 However,the relationship between size and sedimen-tation velocity used in this test method assumes that particlessediment within the laminar flow regime.It is generallyaccepted that particles sedimenting with a Reynolds number of0.3 or less will do so under conditions of laminar flow withnegligible error.Particle size distribution analysis for particlessettling with a larger Reynolds number may be incorrect due toturbulent flow.Some materials covered by this test methodmay settle in water with a Reynolds number greater than 0.3 iflarge particles are present.The user of this test method shouldcalculate the Reynolds number of the largest particle expectedto be present in order to judge the quality of obtained results.Reynolds number(Re)can be calculated using the followingequation:Re5D3 2 0!0g182(1)where:D=the diameter of the largest particle expected to bepresent,in cm,=the particle density,in g/cm3,0=the suspending liquid density,in g/cm3,g=the acceleration due to gravity,981 cm/sec2,and=the suspending liquid viscosity,in poise.1.1.2 A table of the largest particles that can be analyzedwith a suggested maximum Reynolds number of 0.3 or less inwater at 35 C is given for a number of materials in Table 1.Acolumn of the Reynolds number calculated for a 50-m particlesedimenting in the same liquid system is also given for eachmaterial.Larger particles can be analyzed in dispersing mediawith viscosities greater than that for water.Aqueous solutionsof glycerine or sucrose have such higher viscosities.1.2 The procedure described in this test method may beapplied successfully to other ceramic powders in this generalsize range,provided that appropriate dispersion procedures aredeveloped.It is the responsibility of the user to determine theapplicability of this test method to other materials.Notehowever that some ceramics,such as boron carbide and boronnitride,may not absorb X-rays sufficiently to be characterizedby this analysis method.1.3 The values stated in cgs units are to be regarded as thestandard,which is the long-standing industry practice.Thevalues given in parentheses are for information only.1.4 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 applica-bility of regulatory limitations prior to use.Specific hazardinformation is given in Section 8.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C1145 Terminology of Advanced CeramicsE1617 Practice for Reporting Particle Size CharacterizationData3.Terminology3.1 For definitions of terms used in this test method,refer toTerminology C1145.1This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.03 onPhysical Properties and Non-Destructive Evaluation.Current edition approved July 1,2017.Published July 2017.Originally approvedin 2017.DOI:10.1520/C1730-17.2For 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 Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 4.Summary of Test Method4.1 A carefully dispersed homogeneous suspension of thepowder is permitted to settle in a cell scanned by a collimatedX-ray beam of constant intensity.The net X-ray signal isinversely proportional to the sample concentration in thedispe