ASTM B822-97

Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering

SCOPE
1.1 This test method covers the determination of the particle size distribution by light scattering, reported as volume percent, of particulate materials including metals and compounds.
1.2 This test method applies to analyses with both aqueous and nonaqueous dispersions. In addition, analysis can be performed with a gaseous dispersion for materials that are hygroscopic or react with a liquid carrier.
1.3 This test method is applicable to the measurement of particulate materials in the range of 0.4 to 2000 m, or a subset of that range, as applicable to the particle size distribution being measured.
1.4 The values stated in SI units are to be regarded as the standard.
1.5 This standard does not purport to address all of the safety concerns, 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: 09-Apr-2002
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Relations

• Replaced By: ASTM B822-02 - Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering
• Effective Date: 10-Apr-2002
• Referred By: ASTM F3049-14(2021) - Standard Guide for Characterizing Properties of Metal Powders Used for Additive Manufacturing Processes
• Effective Date: 10-Apr-2002
• Referred By: ASTM B859-21 - Standard Practice for De-Agglomeration of Refractory Metal Powders and Their Compounds Prior to Particle Size Analysis
• Effective Date: 10-Apr-2002
• Referred By: ASTM F3554-22 - Standard Specification for Additive Manufacturing – Finished Part Properties – Grade 4340 (UNS G43400) via Laser Beam Powder Bed Fusion for Transportation Applications
• Effective Date: 10-Apr-2002
• Referred By: ASTM F3560-22 - Standard Specification for Additive Manufacturing – Data – Common Exchange Format for Particle Size Analysis by Light Scattering
• Effective Date: 10-Apr-2002
• Referred By: ASTM B821-23 - Standard Guide for Liquid Dispersion of Metal Powders and Related Compounds for Particle Size Analysis
• Effective Date: 10-Apr-2002
• Referred By: ASTM F1377-21 - Standard Specification for Cobalt-28Chromium-6Molybdenum Powder for Medical Devices (UNS R30075, UNS R31537, and UNS R31538)
• Effective Date: 10-Apr-2002
• Referred By: ASTM G211-14(2020) - Standard Test Method for Conducting Elevated Temperature Erosion Tests by Solid Particle Impingement Using Gas Jets
• Effective Date: 10-Apr-2002
• Referred By: ASTM F3456-22 - Standard Guide for Powder Reuse Schema in Powder Bed Fusion Processes for Medical Applications for Additive Manufacturing Feedstock Materials
• Effective Date: 10-Apr-2002
• Referred By: ASTM C750-18 - Standard Specification for Nuclear-Grade Boron Carbide Powder
• Effective Date: 10-Apr-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: B 822 – 97
Standard Test Method for
Particle Size Distribution of Metal Powders and Related
Compounds by Light Scattering
This standard is issued under the fixed designation B 822; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope large compared to the wavelength of the incident light.
3.2.3 Mie Scattering—the complex electromagnetic theory
1.1 This test method covers the determination of the particle
that describes the scattering of light by spherical particles. It is
size distribution by light scattering, reported as volume per-
usually applied to particles with diameters that are close to the
cent, of particulate materials including metals and compounds.
wavelength of the incident light. The real and imaginary
1.2 This test method applies to analyses with both aqueous
indices of light refraction of the particles are needed.
and nonaqueous dispersions. In addition, analysis can be
3.2.4 multiple scattering—the rescattering of light by a
performed with a gaseous dispersion for materials that are
particle in the path of light scattered by another particle. This
hygroscopic or react with a liquid carrier.
usually occurs in heavy concentrations of a particle dispersion.
1.3 This test method is applicable to the measurement of
particulate materials in the range of 0.1 to 1000 μm, or a subset
4. Summary of Test Method
of that range, as applicable to the particle size distribution
4.1 A prepared sample of particulate material is dispersed in
being measured.
water, or a compatible organic liquid, and circulated through
1.4 The values stated in SI units are to be regarded as the
the path of a light beam or some other suitable light source. A
standard.
dry sample may be aspirated through the light in a carrier gas.
1.5 This standard does not purport to address all of the
The particles pass through the light beam and scatter it.
safety concerns, if any, associated with its use. It is the
Photodetector arrays collect the scattered light that is converted
responsibility of the user of this standard to establish appro-
to electrical signals, which are then analyzed in a micropro-
priate safety and health practices and determine the applica-
cessor. The signal is converted to a size distribution using
bility of regulatory limitations prior to use.
Fraunhofer Diffraction or Mie Scattering, or a combination of
2. Referenced Documents both. Scattering information is analyzed assuming a spherical
model. Calculated particle sizes are therefore presented as
2.1 ASTM Standards:
equivalent spherical diameters.
B 215 Practices for Sampling Finished Lots of Metal Pow-
ders
5. Significance and Use
B 243 Terminology of Powder Metallurgy
5.1 It is important to recognize that the results obtained by
B 821 Guide for Liquid Dispersion of Metal Powders and
2 this test method, or any other method for particle size deter-
Related Compounds for Particle Size Analysis
mination using different physical principles, may disagree. The
3. Terminology results are strongly influenced by the physical principles
employed by each method of particle size analysis. The results
3.1 Definitions—Definitions of powder metallurgy terms
of any particle sizing method should be used only in a relative
can be found in Terminology B 243.
sense; they should not be regarded as absolute when comparing
3.2 Definitions of Terms Specific to This Standard:
results obtained by other methods.
3.2.1 background—extraneous scattering of light by ele-
5.2 Light scattering theory has been available for many
ments other than the particles to be measured; includes
years for use in the determination of particle size. Several
scattering by contamination in the measurement path.
manufacturers of testing equipment now have units based on
3.2.2 Fraunhofer Diffraction—the optical theory that de-
these principles. Although each type of testing equipment uses
scribes the low-angle scattering of light by particles that are
the same basic principles for light scattering as a function of
particle size, different assumptions pertinent to application of
the theory, and different models for converting light measure-
This test method is under the jurisdiction of ASTM Committee B09 on Metal
ments to particle size, may lead to different results for each
Powders and Metal Powder Productsand is the direct responsibility of Subcommit-
tee B09.02on Base Metal Powders.
Current edition approved April 10, 1997. Published June 1997. Originally
published as B 822 – 92. Last previous edition B 822 – 92. Muly, E. C., Frock, H. N., “Industrial Particle Size Measurement Using Light
Annual Book of ASTM Standards, Vol 02.05. Scattering,” Optical Engineering, Vol 19, No 6, 1980, pp. 861–869.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
B 822
instrument. Therefore, the use of this test method cannot 8. Reagents and Materials
guarantee directly comparable results from different types of
8.1 Purity of Reagents—Reagent grade chemicals shall be
instruments.
used in all tests. Unless otherwise indicated, it is intended that
5.3 Knowledge of the particle size distribution of metal
all reagents shall conform to the specifications of the Commit-
powders is useful in predicting the powder-processing behavior
tee on Analytical Reagents of the American Chemical Society.
and ultimate performance of powder metallurgy parts. Particle
Other grades may be used, provided it is first ascertained that
size distribution is related closely to the flowability, moldabil-
the reagent is of sufficiently high purity to permit its use
ity, compressibility, and die-filling characteristics of a powder,
without lessening the accuracy of the determination.
as well as to the final structure and properties of finished
8.2 Appropriate Application-Specific Carrier, as determined
powder metallurgy (P/M) parts.
by Guide B 821. The carrier shall meet the following condi-
5.4 This test method is useful to both suppliers and users of
tions:
powders in determining the particle size distributions for
8.2.1 It shall be chemically compatible with the construc-
product specifications, manufacturing control, development,
tion material of the sample delivery system,
and research.
8.2.2 It shall not cause dissolution of the particles, and
5.5 This test method may be used to obtain data for
8.2.3 It shall be sufficiently clean to achieve acceptable
comparison between lots of the same material or for establish-
background levels.
ing conformance, as in acceptance testing.
8.3 Antifoaming Agent, or equivalent.
5.6 Reported particle size measurement is a function of both
8.4 Dry, Clean Gas, for gaseous dispersions.
the actual particle dimension and shape factor as well as the
8.5 Appropriate Surfactant, as determined by Guide B 821,
particular physical or chemical properties being measured.
subject to the conditions listed in 8.2.
Caution is required when comparing data from instruments
9. Sampling and Sample Size
operating on different physical or chemical parameters or with
different particle size measurement ranges. Sample acquisition,
9.1 A representative test sample shall be obtained according
handling, and preparation can also affect reported particle size
to Practices B 215. The test portion shal
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