1、Designation: E194 10Standard 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 nu
2、mber 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 method2covers the determination of themineral-acid-insoluble matter content of copper and iron pow-ders in amounts under 1.0 %
3、.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
4、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. Summar
5、y 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 ga
6、ngue, 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
7、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 powde
8、r, 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 bec
9、onverted 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 Mu
10、ffle 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 Vap
11、or 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).1This test method is under the jurisd
12、iction 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 May 1, 2010. Published June 2010. Originallyapproved in 1962. Last previous edition approved in 2006 as E194 06. DOI:10.1520/
13、E0194-10.2Based 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 ref
14、erenced 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.1*A Summary of Changes section appears at the end of this standard.Co
15、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.4 Nitric Acid HNO3(1:1).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 sam
16、ple in a tightly stoppered bottle toprotect it 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
17、 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 wi
18、th distilled water to about 100 mL, andbring 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
19、cool it in a desiccator.9.7 Weigh the crucible 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
20、 the residue.NOTE 2If the ignited residue reserved 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.Rem
21、ove the crucible from the heat and cool. Add 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 dete
22、rmined in 9.10 to calculate the insoluble fraction 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 3 100where:A = insoluble matter, g,B = correction for grams of tin oxide, if present (Note 2),andC = sample us
23、ed, g.IRON POWDER11. Procedure11.1 Transfer5gofthesample, 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 s
24、amples.11.2 With caution, add 100 mL of HCl (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 h
25、ot solution, and wash the residue alternatelywith 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 filt
26、ratewill turn blood-red.NOTE 4If it is desired 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
27、g.11.7 Transfer the filter paper and residue 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-lo
28、ws:Insoluble matter, percent 5 A/B 3 100where: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 M
29、ethod E194 froman interlaboratory study that 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 t
30、esting basedon differences in particle size distribution. Practice E691 wasfollowed for the design and analysis of the data; the details aregiven in an ASTM Research Report.44Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:B09-10
31、09.E194 10214.1.1 The precision information given below is for thecomparison of two test results. The results were obtained fromthe running of three replicates in each 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
32、 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 unless theydiffer by more than r, the repeatability interval.14.1.3 Duplicate results from two different laboratoriesshould be considere
33、d 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 procedure in Test Method E194 for measuring the acidinsoluble content of copper and iron powders because nomaterial having an accepted r
34、eference value is available.15. Keywords15.1 acid insolubles; copper powder; iron powderSUMMARY OF CHANGESCommittee B09 has identified the location of selected changes to this standard since the last issue (E194 06)that may impact the use of this standard. (May 1, 2010)(1) Added potassium thiocyanat
35、e as a reagent in Section 7.(2) Added maintain boiling for about 1 min in subection 9.4.(3) Added maintain boiling for about 1 min in subsection 11.3as well as an additional maintain for about 1 min.(4) Deleted the redundant subsection 11.4 from the priorversion of the standard. Renumbered subsequen
36、t subsections.(5) Added a test for the absence of iron salts in the newsubsection 11.4.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of
37、the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Y
38、our comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your commen
39、ts have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or mu
40、ltiple 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 through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E194 103
