1、Designation: E194 10 (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 l
2、ast 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 am
3、ounts 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 u
4、se.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 Tes
5、t 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 determin
6、e 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
7、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 beprese
8、nt. 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 coppe
9、r 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
10、 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
11、 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
12、(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 editi
13、on 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 Po
14、wders,” 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 Intern
15、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17.5 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 i
16、t from moisture which promotes oxidation of copperand iron.COPPER POWDER9. Procedure9.1 Transfer5gofthesample, weighed to the nearest0.0001 g, to a 250 mL covered casserole.NOTE 1Some operators report better reproducibility when increasingthe metal powder sample size to 10 g. Nevertheless, the preci
17、sionstatement 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 mL, andbring
18、to a boil. Maintain boiling for about 1 min.9.5 Filter the hot solution, and wash with hot distilled wateruntil all traces of blue color (copper salts) disappear.9.6 Prepare a quartz or porcelain crucible by pre-heating for40 min in air at 980 C and then cool it in a desiccator.9.7 Weigh the crucibl
19、e to the nearest 0.0001 g.9.8 Transfer the filter paper and residue to the crucible.9.9 Dry, and then ignite in a furnace at 980 C for 1 h.9.10 Cool in a desiccator and reweigh to the nearest0.0001 g. The difference in mass is the insoluble matter.Reserve the residue.NOTE 2If the ignited residue res
20、erved from 9.2 is suspected to containtin oxide, add5gofNH4I to the crucible. Reheat the crucible and contentsin air with a bunsen burner to a dull-red temperature or place in a furnaceat 600 C minimum for 15 min or until all fumes have been dispelled.Remove the crucible from the heat and cool. Add
21、2 to 3 mL of HNO3,evaporate to dryness, ignite and weigh to the nearest 0.0001 g. Repeat thetreatment with NH4I and HNO3until constant mass is obtained. The lossin mass represents tin oxide. Subtract this loss in mass from the mass ofinsoluble matter determined in 9.10 to calculate the insoluble fra
22、ction thatis free of tin oxide.10. Calculation10.1 Calculate the percentage of insoluble matter as fol-lows:Insoluble matter, percent 5 A 2 B!/C# 3100where:A = insoluble matter, g,B = correction for grams of tin oxide, if present (Note 2),andC = sample used, g.IRON POWDER11. Procedure11.1 Transfer5g
23、ofthesample, weighed to the nearest0.0001 g, to a 750 mL covered casserole.NOTE 3Some 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.11.2 With caution, add 100 mL of HCl (
24、1:1) (Note 4), andlet stand at room temperature until the reaction is complete.11.3 Heat the solution to boiling on a hot plate. Maintainboiling for about 1 min. Then add 150 mL of water, and reheatto boiling and maintain for about 1 min.11.4 Filter the hot solution, and wash the residue alternately
25、with hot HCl (1:25) and hot distilled water, six times with each,to ensure the removal of all iron salts. The absence of iron saltsin the filtrate may be checked by the addition of a 5 % solutionof potassium thiocyanate. If iron salts are present the filtratewill turn blood-red.NOTE 4If it is desire
26、d to exclude carbides from the reported insolublematter, add 20 mL of HNO3to the HCl (1:1).11.5 Prepare a quartz or porcelain crucible by pre-heatingfor 40 min in air at 980 C and then cool it in a dessicator.11.6 Weigh the crucible to the nearest 0.0001 g.11.7 Transfer the filter paper and residue
27、to the crucible.11.8 Dry, and then ignite in a furnace at 980 C for 1 h.11.9 Cool in a desiccator and reweigh to the nearest0.0001 g. The difference in mass is the insoluble matter.12. Calculation12.1 Calculate the percentage of insoluble matter as fol-lows:Insoluble matter, percent 5 A/B# 3100where
28、:A = insoluble matter, g, andB = sample used, g.13. Report13.1 Report the total insoluble matter as a percentage to thenearest 0.01 %.14. Precision and Bias14.1 PrecisionThe following precision data were devel-oped using the procedures contained in Test Method E194 froman interlaboratory study that
29、performed six sets of tests. Thepercent insoluble was determined for four samples: a 325mesh iron, a 60 mesh iron, a 325 mesh copper, and a 60mesh copper. The different particle sizes were used to deter-mine if there were any effects on the precision of testing basedon differences in particle size d
30、istribution. Practice E691 wasE194 10 (2015)2followed for the design and analysis of the data; the details aregiven in an ASTM Research Report.414.1.1 The precision information given below is for thecomparison of two test results. The results were obtained fromthe running of three replicates in each
31、 test on each sample.325Iron60Iron325Copper60CopperAverage, % 0.29 0.08 0.11 0.09Sr, % 0.022 0.012 0.013 0.019SR, % 0.051 0.025 0.036 0.063r, % 0.06 0.03 0.04 0.05R, % 0.14 0.07 0.10 0.1814.1.2 Duplicate results from the same laboratory should beconsidered acceptable at the 95 % confidence level unl
32、ess theydiffer by more than r, the repeatability interval.14.1.3 Duplicate results from two different laboratoriesshould be considered acceptable at the 95 % confidence levelunless they differ by more than R, the reproducibility interval.14.2 BiasNo information can be presented on the bias ofthe pro
33、cedure in Test Method E194 for measuring the acidinsoluble content of copper and iron powders because nomaterial having an accepted reference value is available.15. Keywords15.1 acid insolubles; copper powder; iron powderASTM International takes no position respecting the validity of any patent righ
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37、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or
38、 through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:B09-1009.E194 10 (2015)3
