Designation:C1730−17StandardTestMethodforParticleSizeDistributionofAdvancedCeramicsbyX-RayMonitoringofGravitySedimentation1ThisstandardisissuedunderthefixeddesignationC1730;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofparticlesizedistributionofadvancedceramicpowders.Experiencehasshownthatthistestmethodissatisfactoryfortheanalysisofsiliconcarbide,siliconnitride,andzirconiumoxideinthesizerangeof0.1upto50µm.1.1.1However,therelationshipbetweensizeandsedimen-tationvelocityusedinthistestmethodassumesthatparticlessedimentwithinthelaminarflowregime.ItisgenerallyacceptedthatparticlessedimentingwithaReynoldsnumberof0.3orlesswilldosounderconditionsoflaminarflowwithnegligibleerror.ParticlesizedistributionanalysisforparticlessettlingwithalargerReynoldsnumbermaybeincorrectduetoturbulentflow.SomematerialscoveredbythistestmethodmaysettleinwaterwithaReynoldsnumbergreaterthan0.3iflargeparticlesarepresent.TheuserofthistestmethodshouldcalculatetheReynoldsnumberofthelargestparticleexpectedtobepresentinordertojudgethequalityofobtainedresults.Reynoldsnumber(Re)canbecalculatedusingthefollowingequation:Re5D3~ρ2ρ0!ρ0g18η2(1)where:D=thediameterofthelargestparticleexpectedtobepresent,incm,ρ=theparticledensity,ing/cm3,ρ0=thesuspendingliquiddensity,ing/cm3,g=theaccelerationduetogravity,981cm/sec2,andη=thesuspendingliquidviscosity,inpoise.1.1.2AtableofthelargestparticlesthatcanbeanalyzedwithasuggestedmaximumReynoldsnumberof0.3orlessinwaterat35°CisgivenforanumberofmaterialsinTable1.AcolumnoftheReynoldsnumbercalculatedfora50-µmparticlesedimentinginthesameliquidsystemisalsogivenforeachmaterial.Largerparticlescanbeanalyzedindispersingmediawithviscositiesgreaterthanthatforwater.Aqueoussolutionsofglycerineorsucrosehavesuchhighervisco...
