ASTM_C_1494_-_13.pdf

Designation:C149413Standard Test Methods forDetermination of Mass Fraction of Carbon,Nitrogen,andOxygen in Silicon Nitride Powder1This standard is issued under the fixed designation C1494;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 These test methods cover the determination of massfraction%of carbon,nitrogen and oxygen in silicon nitridepowder having chemical compositions within the followinglimits:ElementMass Fraction%RangeCarbon0.05 to 5.0Nitrogen30 to 45Oxygen0.1 to 1.51.2 Two test methods appear in this standard.1.2.1 Total Carbon by the Direct Combustion-Infrared Mea-surement Method.1.2.2 Nitrogen by the Inert Gas Fusion-Thermal Conductiv-ity Measurement Method and Oxygen by the Inert GasFusion-Infrared Measurement Method.1.3 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 hazardstatements are given in Section 6.2.Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus,Reagents,and Safety Consid-erations for Chemical Analysis of Metals,Ores,andRelated MaterialsE1019 Test Methods for Determination of Carbon,Sulfur,Nitrogen,and Oxygen in Steel,Iron,Nickel,and CobaltAlloys by Various Combustion and Fusion TechniquesE1806 Practice for Sampling Steel and Iron for Determina-tion of Chemical Composition3.Significance and Use3.1 These test methods are for the chemical analysis of massfraction of carbon,nitrogen and oxygen in silicon nitridepowder.They are used in research,development,production,acceptance,and quality control of silicon nitride powders usedto produce ceramic components with silicon nitride content.3.2 It is assumed that all who use these test methods will betrained analysts,capable of performing common laboratoryprocedures skillfully and safely.It is expected that work will beperformed in a properly equipped laboratory.4.Apparatus and Reagents4.1 The procedure was written with commercial carbon andnitrogen/oxygen analyzers in mind.For any other analyzer,theinstrument manual specific to that analyzer shall be consultedfor instrument set-up.4.2 Specific apparatus and reagents required for each deter-mination are listed in separate sections preceding the procedure.5.Sampling5.1 Procedures for sampling the materials refer to thoseparts of Practice E1806 pertaining to solid form samples of thetype used for instrumental analysis.6.Hazards6.1 For hazards to be observed in the use of certain reagentsin this test method,refer to Practice E50.6.2 Use care when handling hot crucibles and operatingfurnaces to avoid personal injury by either burn or electricalshock.7.Total Carbon in Silicon Nitride Powder by DirectCombustionInfrared Detection Method7.1 ScopeThis test method covers the determination ofcarbon in concentrations from 0.05 to 5.0%mass fraction.1These test methods are under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and are the direct responsibility of Subcommittee C28.03 onPhysical Properties and Non-Destructive Evaluation.Current edition approved Aug.1,2013.Published January 2014.Originallyapproved in 2001.Last previous edition approved in 2007 as C1494 01(2007).DOI:10.1520/C1494-13.2For 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 States1 7.2 Summary of Test Method3The carbon is converted tocarbon dioxide by combustion in a stream of oxygen.Theamount of carbon dioxide is measured by infrared(IR)absorption.7.3 ApparatusThis test method is written for use withcommercial carbon analyzers,equipped to carry out the analy-ses operations automatically and calibrated using steel stan-dards with known concentrations of carbon.The operatingprinciples,specifications and descriptions of commercial car-bon analyzers are given in the Practice of E1019.7.4 Reagents and Materials:7.4.1 CruciblesExpendable ceramic(alumina)or similarrefractory crucibles as specified by commercial carbon analyz-ers manufacturers.Both the crucible and cover,if used,mustbe prebaked for a sufficient time to produce constant blankvalues.Use the prebake schedule recommended by the instru-ment manufacturer.7.4.2 Crucible TongsCapable of handling recommendedcrucibles with respect to their sizes,shape and temperature.7.4.3 AcceleratorsCarbon f