ASTM C1730-17
(Test Method)Standard Test Method for Particle Size Distribution of Advanced Ceramics by X-Ray Monitoring of Gravity Sedimentation
Standard Test Method for Particle Size Distribution of Advanced Ceramics by X-Ray Monitoring of Gravity Sedimentation
SIGNIFICANCE AND USE
5.1 This test method is useful to both suppliers and users of powders, as outlined in 1.1 and 1.2, in determining particle size distribution for product specifications, manufacturing control, development, and research.
5.2 Users should be aware that sample concentrations used in this test method may not be what are considered ideal by some authorities, and that the range of this test method extends into the region where Brownian movement could be a factor in conventional sedimentation. Within the range of this test method, neither the sample concentration nor Brownian movement is believed to be significant. Standard reference materials traceable to national standards, of chemical composition specifically covered by this test method, are available from NIST,3 and perhaps other suppliers.
5.3 Reported particle size measurement is a function of the actual particle dimension and shape factor as well as the particular physical or chemical properties being measured. Caution is required when comparing data from instruments operating on different physical or chemical parameters or with different particle size measurement ranges. Sample acquisition, handling, and preparation can also affect reported particle size results.
5.4 Suppliers and users of data obtained using this test method need to agree upon the suitability of these data to provide specification for and allow performance prediction of the materials analyzed.
SCOPE
1.1 This test method covers the determination of particle size distribution of advanced ceramic powders. Experience has shown that this test method is satisfactory for the analysis of silicon carbide, silicon nitride, and zirconium oxide in the size range of 0.1 up to 50 µm.
1.1.1 However, the relationship between size and sedimentation velocity used in this test method assumes that particles sediment within the laminar flow regime. It is generally accepted that particles sedimenting with a Reynolds number of 0.3 or less will do so under conditions of laminar flow with negligible error. Particle size distribution analysis for particles settling with a larger Reynolds number may be incorrect due to turbulent flow. Some materials covered by this test method may settle in water with a Reynolds number greater than 0.3 if large particles are present. The user of this test method should calculate the Reynolds number of the largest particle expected to be present in order to judge the quality of obtained results. Reynolds number (Re) can be calculated using the following equation:
where:
D = the diameter of the largest particle expected to be present, in cm, ρ = the particle density, in g/cm3, ρ0 = the suspending liquid density, in g/cm3, g = the acceleration due to gravity, 981 cm/sec2, and η = the suspending liquid viscosity, in poise.
1.1.2 A table of the largest particles that can be analyzed with a suggested maximum Reynolds number of 0.3 or less in water at 35 °C is given for a number of materials in Table 1. A column of the Reynolds number calculated for a 50-µm particle sedimenting in the same liquid system is also given for each material. Larger particles can be analyzed in dispersing media with viscosities greater than that for water. Aqueous solutions of glycerine or sucrose have such higher viscosities.
TABLE 1 Maximum Diameter of Ceramic Powders That Can Be Analyzed with Reynolds Number of 0.3 or Less in Water at 35 °C
Particle Composition
Particle Density
Maximum Particle Diameter, µm
Reynolds Number for 50 µmA
Aluminum Nitride
3.26
50.36
0.29
Aluminum Oxide
3.965
46.01
0.39
Cerium Dioxide
7.132
36.13
0.80
Silicon Carbide
3.217
50.68
0.29
Silicon Nitride
3.44
49.09
0.32
Yttrium Oxide
5.01
41.61
0.52
Zirconium Oxide
5.89
38.95
0.63(A) A Reynolds number calculated for 50-µm particles sedimenting in water at 35 °C, with...
General Information
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C1730 − 17
Standard Test Method for
Particle Size Distribution of Advanced Ceramics by X-Ray
1
Monitoring of Gravity Sedimentation
This standard is issued under the fixed designation C1730; 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 with viscosities greater than that for water. Aqueous solutions
of glycerine or sucrose have such higher viscosities.
1.1 This test method covers the determination of particle
size distribution of advanced ceramic powders. Experience has
1.2 The procedure described in this test method may be
shown that this test method is satisfactory for the analysis of
applied successfully to other ceramic powders in this general
silicon carbide, silicon nitride, and zirconium oxide in the size
size range, provided that appropriate dispersion procedures are
range of 0.1 up to 50 µm.
developed. It is the responsibility of the user to determine the
1.1.1 However, the relationship between size and sedimen-
applicability of this test method to other materials. Note
tation velocity used in this test method assumes that particles
however that some ceramics, such as boron carbide and boron
sediment within the laminar flow regime. It is generally
nitride, may not absorb X-rays sufficiently to be characterized
accepted that particles sedimenting with a Reynolds number of
by this analysis method.
0.3 or less will do so under conditions of laminar flow with
1.3 The values stated in cgs units are to be regarded as the
negligible error. Particle size distribution analysis for particles
standard, which is the long-standing industry practice. The
settling with a larger Reynolds number may be incorrect due to
values given in parentheses are for information only.
turbulent flow. Some materials covered by this test method
1.4 This standard does not purport to address all of the
may settle in water with a Reynolds number greater than 0.3 if
safety concerns, if any, associated with its use. It is the
large particles are present. The user of this test method should
responsibility of the user of this standard to establish appro-
calculate the Reynolds number of the largest particle expected
priate safety and health practices and determine the applica-
to be present in order to judge the quality of obtained results.
bility of regulatory limitations prior to use. Specific hazard
Reynolds number (Re) can be calculated using the following
information is given in Section 8.
equation:
1.5 This international standard was developed in accor-
3
D ρ 2 ρ ρ g
~ !
0 0
Re 5 (1) dance with internationally recognized principles on standard-
2
18η
ization established in the Decision on Principles for the
where:
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
D = the diameter of the largest particle expected to be
Barriers to Trade (TBT) Committee.
present, in cm,
3
ρ = the particle density, in g/cm ,
3
ρ = the suspending liquid density, in g/cm ,
2. Referenced Documents
0
2
g = the acceleration due to gravity, 981 cm/sec , and
2
2.1 ASTM Standards:
η = the suspending liquid viscosity, in poise.
C1145 Terminology of Advanced Ceramics
1.1.2 A table of the largest particles that can be analyzed
E1617 Practice for Reporting Particle Size Characterization
with a suggested maximum Reynolds number of 0.3 or less in
Data
water at 35 °C is given for a number of materials in Table 1.A
columnoftheReynoldsnumbercalculatedfora50-µmparticle
3. Terminology
sedimenting in the same liquid system is also given for each
3.1 For definitions of terms used in this test method, refer to
material. Larger particles can be analyzed in dispersing media
Terminology C1145.
1
This test method is under the jurisdiction of ASTM Committee C28 on
2
Advanced Ceramics and is the direct responsibility of Subcommittee C28.03 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Physical Properties and Non-Destructive Evaluation. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved July 1, 2017. Published July 2017. Originally approved Standards volume information, refer to the standard’s Document Summary page on
in 2017. DOI: 10.1520/C1730-17. the ASTM website.
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C1730 − 17
TABLE 1 Maximum Diameter of Ceramic Powders That Can Be Analyzed with Reynolds Number of 0.3 or Less in Water at 35 °C
A
Particle Composition Particle Density Ma
...
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