ASTM_E_159_-_10.pdf

Designation:E15910Standard Test Method forLoss of Mass in a Reducing Gas Atmosphere for Cobalt,Copper,Tungsten,and Iron Powders(Hydrogen Loss)1This standard is issued under the fixed designation E159;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.Scope*1.1 This test method covers the determination of the mass ofhydrogen-reducible constituents in the following metal pow-ders:cobalt,copper,iron,and tungsten.1.2This test method is useful for cobalt,copper,and ironpowders in the range from 0.05 to 3.0%oxygen,and fortungsten powder in the range from 0.01 to 0.50%oxygen.1.3 This test method does not measure the oxygen containedin oxides such as silicon oxide(SiO2),aluminum oxide(Al2O3),magnesium oxide(MgO),calcium oxide(CaO),titanium dioxide(TiO2),etc.that are not reduced by hydrogenat the test temperatures.1.4 For total oxygen content,vacuum or inert gas fusionmethods are available(see Test Methods E1019).1.5 The values stated in SI units are to be regarded as thestandard.1.6 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.2.Referenced Documents2.1 ASTM Standards:2B215 Practices for Sampling Metal PowdersB243 Terminology of Powder MetallurgyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1019 Test Methods for Determination of Carbon,Sulfur,Nitrogen,and Oxygen in Steel,Iron,Nickel,and CobaltAlloys by Various Combustion and Fusion Techniques3.Terminology3.1 DefinitionsDefinitions of powder metallurgy termscan be found in Terminology B243.Additional descriptiveinformation on powder metallurgy is available in the RelatedMaterial section of Vol 02.05 of the Annual Book of ASTMStandards.4.Summary of Test Method4.1 This test method consists of subjecting a sample ofpowder to the action of a hydrogen-containing gas understandard conditions of temperature and time and measuring theresulting loss of mass.5.Significance and Use5.1 The oxygen content of a powder affects both its greenand sintered properties.5.2 Hydrogen loss is a term widely used in the powdermetallurgy industry even though the measurement representsan approximate oxygen content of the powder.5.3 Oxygen is the most common hydrogen-reducible con-stituent of metal powders,and this procedure may be used as ameasure of oxygen,reducible under the test conditions,if otherinterfering elements are absent.6.Interferences6.1 If carbon or sulfur is present,or both,are present,theywill be largely removed in the test.Their loss in mass isincluded in the total loss in mass measurement and must besubtracted from the total mass loss.6.2 If metals or compounds are present that vaporize at thetest temperature(such as cadmium,lead,zinc,etc.),their effectis included in the loss of mass measurement and must besubtracted from the total mass loss.6.3 If some components are present that are oxidized orhydrided during the test,there is a gain in mass that must beadded to the total mass loss.7.Apparatus7.1 Furnace,capable of operating at the prescribed tem-perature.1This test method is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.02 on Base Metal Powders.Current edition approved July 1,2010.Published August 2010.Originallyapproved in 1986.Last previous edition approved in 2006 as E159 06.DOI:10.1520/E0159-10.2For 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.*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 7.2 Temperature Control,capable of maintaining tempera-tures to 615 C.7.3 Gastight Ceramic or Metallic Combustion Tube.7.4 Flow Meter,to measure flow of hydrogen.7.5 Combustion Boat,composed of alundum,quartz,ornickel,depending on the test conditions.The boat shall be ofsuch dimensions,for example 75 mm long and 12 mm wide,that the thickness of powder,when uniformly distributed,doesnot exceed 3 mm.7.6 Balance,suitable for determining mass to the nearest0.0001 g.8.Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may be