ASTM E194-10(2015)

Standard Test Method for Acid-Insoluble Content of Copper and Iron Powders

SIGNIFICANCE AND USE
4.1 The purpose of this test method is to determine the amount of gangue, refractory, inert, etc., materials, that may adversely affect compacting tools and sintered properties of components formed from copper and iron powders.  
4.2 The insoluble matter consists of those nonmetallic substances that do not dissolve in the mineral acid used to dissolve the metal. In copper powder, which is treated with nitric acid, the acid-insoluble matter includes silica, insoluble silicates, alumina, clays, and other refractory materials that may be introduced either as impurities in the raw material or from the furnace lining, fuel, etc.; lead sulfate may also be present. In iron powder, which is treated with hydrochloric acid, the insoluble matter may include carbides in addition to the substances listed above. The test method excludes insoluble material that is volatile at the ignition temperature specified.
SCOPE
1.1 This test method2 covers the determination of the mineral-acid-insoluble matter content of copper and iron powders in amounts under 1.0 %.  
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2015
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E194 − 10 (Reapproved 2015)
Standard Test Method for
Acid-Insoluble Content of Copper and Iron Powders
This standard is issued under the fixed designation E194; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 The insoluble matter consists of those nonmetallic
substances that do not dissolve in the mineral acid used to
1.1 This test method covers the determination of the
dissolve the metal. In copper powder, which is treated with
mineral-acid-insoluble matter content of copper and iron pow-
nitric acid, the acid-insoluble matter includes silica, insoluble
ders in amounts under 1.0 %.
silicates, alumina, clays, and other refractory materials that
1.2 This standard does not purport to address all of the
may be introduced either as impurities in the raw material or
safety problems, if any, associated with its use. It is the
from the furnace lining, fuel, etc.; lead sulfate may also be
responsibility of the user of this standard to establish appro-
present. In iron powder, which is treated with hydrochloric
priate safety and health practices and determine the applica-
acid, the insoluble matter may include carbides in addition to
bility of regulatory limitations prior to use.
thesubstanceslistedabove.Thetestmethodexcludesinsoluble
material that is volatile at the ignition temperature specified.
2. Referenced Documents
5. Interferences
2.1 ASTM Standards:
B215 Practices for Sampling Metal Powders
5.1 Any metallic tin present in the copper powder will be
E50 Practices for Apparatus, Reagents, and Safety Consid-
converted into the insoluble tin oxide by the nitric acid
erations for Chemical Analysis of Metals, Ores, and
treatment; in such cases, provision shall be made for the
Related Materials
determination of tin oxide and the appropriate correction
E691 Practice for Conducting an Interlaboratory Study to
applied.
Determine the Precision of a Test Method
6. Apparatus
3. Summary of Test Method
6.1 Apparatus and reagents shall conform to the require-
3.1 The sample is dissolved in the appropriate acid: nitric
ments prescribed in Practices E50.
acid (HNO ) for copper, hydrochloric acid (HCl) for iron. The
6.2 Hot Plate.
insoluble matter is filtered out and ignited in a furnace at
6.3 Muffle Furnace, capable of operating at 980 °C.
980 °C for 1 h.
6.4 Casseroles (non-metallic), 250 mL and 750 mL.
4. Significance and Use
6.5 Glass Funnel.
4.1 The purpose of this test method is to determine the
6.6 Quart or Porcelain Crucible.
amount of gangue, refractory, inert, etc., materials, that may
6.7 Desiccator.
adversely affect compacting tools and sintered properties of
components formed from copper and iron powders.
6.8 Analytical Balance, having a sensitivity of 0.1 mg.
6.9 Filter Paper, Whatman No. 541 or one of equivalent
pore size and ash content.
This test method is under the jurisdiction of ASTM Committee B09 on Metal
Powders and Metal Powder Products and is the direct responsibility of Subcom-
6.10 Vapor Collection System, suitable to provide adequate
mittee B09.02 on Base Metal Powders.
operator protection from chemical vapors resulting from the
CurrenteditionapprovedOct.1,2015.PublishedJune2010.Originallyapproved
in 1962. Last previous edition approved in 2010 as E194 – 10. DOI: 10.1520/ acid digestion steps and muffle furnace ignition steps.
E0194-10R15.
Based on the method developed by the Metal Powder Association (now the
7. Reagents
Metal Powder Producers Association of the Metal Powder Industries Federation)
7.1 Hydrochloric Acid HCl (1:1).
and described in MPIF Standard 06, “Determination of Acid Insoluble Matter in
Iron and Copper Powders,” which is a standard of the MPIF.
7.2 Hydrochloric Acid HCl (1:25).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
7.3 Nitric Acid (HNO ).
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 7.4 Nitric Acid HNO (1:1).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E194 − 10 (2015)
7.5 Ammonium Iodide (NH I). IRON POWDER
7.6 Potassium Thiocyanate (5%).
11. Procedure
8. Sampling
11.1 Transfer5gofthe sample, weighed to the nearest
0.0001 g, to a 750 mL covered casserole.
8.1 The metal powder shall be sampled in accordance with
Practices B215.
NOTE 3—Some operators report better reproducibility when increasing
8.2 Store the test sample in a tightly stoppered bottle to the metal powder sample size to 10 g. Nevertheless, the precision
statement listed in Section 14 was based on 5 g samples.
protect it from moisture which promotes oxidation of copper
and iron.
11.2 With caution, add 100 mL of HCl (1:1) (Note 4), and
let stand at room temperature until the reaction is complete.
COPPER POWDER
11.3 Heat the solution to boiling on a hot plate. Maintain
9. Procedure
boiling for about 1 min. Then add 150 mLof water, and reheat
to boiling and maintain for about 1 min.
9.1 Transfer5gofthe sample, weighed to the nearest
0.0001 g, to a 250 mL covered casserole.
11.4 Filter the hot solution, and wash the residue alternately
withhotHCl(1:25)andhotdistilledwater,sixtimeswitheach,
NOTE 1—Some operators report better reproducibility when increasing
the metal powder sample size to 10 g. Nevertheless, the precision
to ensure the removal of all iron salts.The absence of iron salts
statement listed in Section 14 was based on 5 g samples.
in the filtrate may be checked by t
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E194 − 10 E194 − 10 (Reapproved 2015)
Standard Test Method for
Acid-Insoluble Content of Copper and Iron Powders
This standard is issued under the fixed designation E194; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*Scope
1.1 This test method covers the determination of the mineral-acid-insoluble matter content of copper and iron powders in
amounts under 1.0 %.
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
B215 Practices for Sampling Metal Powders
E50 Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Summary of Test Method
3.1 The sample is dissolved in the appropriate acid: nitric acid (HNO ) for copper, hydrochloric acid (HCl) for iron. The
insoluble matter is filtered out and ignited in a furnace at 980 °C for 1 h.
4. Significance and Use
4.1 The purpose of this test method is to determine the amount of gangue, refractory, inert, etc., materials, that may adversely
affect compacting tools and sintered properties of components formed from copper and iron powders.
4.2 The insoluble matter consists of those nonmetallic substances that do not dissolve in the mineral acid used to dissolve the
metal. In copper powder, which is treated with nitric acid, the acid-insoluble matter includes silica, insoluble silicates, alumina,
clays, and other refractory materials that may be introduced either as impurities in the raw material or from the furnace lining, fuel,
etc.; lead sulfate may also be present. In iron powder, which is treated with hydrochloric acid, the insoluble matter may include
carbides in addition to the substances listed above. The test method excludes insoluble material that is volatile at the ignition
temperature specified.
5. Interferences
5.1 Any metallic tin present in the copper powder will be converted into the insoluble tin oxide by the nitric acid treatment; in
such cases, provision shall be made for the determination of tin oxide and the appropriate correction applied.
6. Apparatus
6.1 Apparatus and reagents shall conform to the requirements prescribed in Practices E50.
6.2 Hot Plate.
6.3 Muffle Furnace, capable of operating at 980 °C.
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.02
on Base Metal Powders.
Current edition approved May 1, 2010Oct. 1, 2015. Published June 2010. Originally approved in 1962. Last previous edition approved in 20062010 as
E194 – 06.E194 – 10. DOI: 10.1520/E0194-10.10.1520/E0194-10R15.
Based on the method developed by the Metal Powder Association (now the Metal Powder Producers Association of the Metal Powder Industries Federation) and described
in MPIF Standard 06, “Determination of Acid Insoluble Matter in Iron and Copper Powders,” which is a standard of the MPIF.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E194 − 10 (2015)
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 equivalent pore size and ash content.
6.10 Vapor Collection System, suitable to provide adequate operator protection from chemical vapors resulting from the acid
digestion steps and muffle furnace ignition steps.
7. Reagents
7.1 Hydrochloric Acid HCl (1:1).
7.2 Hydrochloric Acid HCl (1:25).
7.3 Nitric Acid (HNO ).
7.4 Nitric Acid HNO (1:1).
7.5 Ammonium Iodide (NH I).
7.6 Potassium Thiocyanate (5%).
8. Sampling
8.1 The metal powder shall be sampled in accordance with Practices B215.
8.2 Store the test sample in a tightly stoppered bottle to protect it from moisture which promotes oxidation of copper and iron.
COPPER POWDER
9. Procedure
9.1 Transfer 5 g of the sample, weighed to the nearest 0.0001 g, to a 250 mL covered casserole.
NOTE 1—Some operators report better reproducibility when increasing the metal powder sample size to 10 g. Nevertheless, the precision statement
listed in Section 14 was based on 5 g samples.
9.2 Add 100 mL of HNO (1:1) and let stand at room temperature until the reaction is complete.
9.3 Place the casserole on a hot plate and boil until the volume is reduced to 50 mL.
9.4 Cool, dilute with distilled water to about 100 mL, and bring to a boil. Maintain boiling for about 1 min.
9.5 Filter the hot solution, and wash with hot distilled water until all traces of blue color (copper salts) disappear.
9.6 Prepare a quartz or porcelain crucible by pre-heating for 40 min in air at 980 °C and then 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 nearest
0.0001 g. The difference in mass is the insoluble matter. Reserve the residue.
NOTE 2—If the ignited residue reserved from 9.2 is suspected to contain tin oxide, add 5 g of NH I to the crucible. Reheat the crucible and contents
...