ASTM_E_194_-_10_2015.pdf

Designation:E19410(Reapproved 2015)Standard Test Method forAcid-Insoluble Content of Copper and Iron Powders1This standard is issued under the fixed designation E194;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 method2covers the determination of themineral-acid-insoluble matter content of copper and iron pow-ders in amounts under 1.0%.1.2 This standard does not purport to address all of thesafety problems,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:3B215 Practices for Sampling Metal PowdersE50 Practices for Apparatus,Reagents,and Safety Consid-erations for Chemical Analysis of Metals,Ores,andRelated MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Summary of Test Method3.1 The sample is dissolved in the appropriate acid:nitricacid(HNO3)for copper,hydrochloric acid(HCl)for iron.Theinsoluble matter is filtered out and ignited in a furnace at980 C for 1 h.4.Significance and Use4.1 The purpose of this test method is to determine theamount of gangue,refractory,inert,etc.,materials,that mayadversely affect compacting tools and sintered properties ofcomponents formed from copper and iron powders.4.2 The insoluble matter consists of those nonmetallicsubstances that do not dissolve in the mineral acid used todissolve the metal.In copper powder,which is treated withnitric acid,the acid-insoluble matter includes silica,insolublesilicates,alumina,clays,and other refractory materials thatmay be introduced either as impurities in the raw material orfrom the furnace lining,fuel,etc.;lead sulfate may also bepresent.In iron powder,which is treated with hydrochloricacid,the insoluble matter may include carbides in addition tothe substances listed above.The test method excludes insolublematerial that is volatile at the ignition temperature specified.5.Interferences5.1 Any metallic tin present in the copper powder will beconverted into the insoluble tin oxide by the nitric acidtreatment;in such cases,provision shall be made for thedetermination of tin oxide and the appropriate correctionapplied.6.Apparatus6.1 Apparatus and reagents shall conform to the require-ments prescribed in Practices E50.6.2 Hot Plate.6.3 Muffle Furnace,capable of operating at 980 C.6.4 Casseroles(non-metallic),250 mL and 750 mL.6.5 Glass Funnel.6.6 Quart or Porcelain Crucible.6.7 Desiccator.6.8 Analytical Balance,having a sensitivity of 0.1 mg.6.9 Filter Paper,Whatman No.541 or one of equivalentpore size and ash content.6.10 Vapor Collection System,suitable to provide adequateoperator protection from chemical vapors resulting from theacid digestion steps and muffle furnace ignition steps.7.Reagents7.1 Hydrochloric Acid HCl(1:1).7.2 Hydrochloric Acid HCl(1:25).7.3 Nitric Acid(HNO3).7.4 Nitric Acid HNO3(1:1).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 Oct.1,2015.Published June 2010.Originally approvedin 1962.Last previous edition approved in 2010 as E194 10.DOI:10.1520/E0194-10R15.2Based on the method developed by the Metal Powder Association(now theMetal Powder Producers Association of the Metal Powder Industries Federation)and described in MPIF Standard 06,“Determination of Acid Insoluble Matter inIron and Copper Powders,”which is a standard of the MPIF.3For 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 7.5 Ammonium Iodide(NH4I).7.6 Potassium Thiocyanate(5%).8.Sampling8.1 The metal powder shall be sampled in accordance withPractices B215.8.2 Store the test sample in a tightly stoppered bottle toprotect it from moisture which promotes oxidation of copperand iron.COPPER POWDER9.Procedure9.1 Transfer 5 g of the sample,weighed to the nearest0.0001 g,to a 250 mL covered casserole.NOTE1Some operators report better reproducibility when increasingthe metal powder sample size to 10 g.Nevertheless,the precisionstatement listed in Section 14 was based on 5 g samples.9.2 Add 100 mL of HNO3(1:1)and let stand at roomtemperature until the reaction is complete.9.3 Place the casserole on a hot plate and boil until thevolume is reduced to 50 mL.9.4 Cool,dilute with distilled water to about 100 m