ASTM C1282-08

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C1282 − 08
StandardTest Method for
Determining the Particle Size Distribution of Advanced
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Ceramics by Centrifugal Photosedimentation
This standard is issued under the fixed designation C1282; 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 aliquot is transferred to the analyzer sample cell, which is
placed in the instrument and subjected to a controlled centrifu-
1.1 This test method covers determination of the particle
gal acceleration at a known or controlled temperature. At
size distribution of advanced ceramic powders specifically
predetermined times related to the sedimentation of specific
silicon nitride and carbides, in the range of 0.1 to 20 µm,
Stokes’ diameters (Note 1), the optical absorbance is recorded
having a median particle diameter from 0.5 to 5.0 µm.
and compared to the initial value to determine the fraction of
1.2 The procedure described in this test method may be
the total sample that has sedimented a specific distance. A
applied successfully to other ceramic powders in this general
volume-based size distribution is calculated from the
size range, provided that appropriate dispersion procedures are
absorbance-time data. The results are reported as equivalent
developed. It is the responsibility of the user to determine the
diameter (spherical) (Note 2) since particles in these powders
applicability of this test method to other materials.
are not truly spherical.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
NOTE 1—This diameter in µm is referred to as D in the equation given
below.
only.
NOTE 2—Refer to Terminology C242 for the ASTM definition of this
1.4 This standard does not purport to address all of the
term. Most equipment manufacturers refer to this as the equivalent
safety concerns, if any, associated with its use. It is the
spherical diameter.
responsibility of the user of this standard to establish appro-
X
priate safety and health practices and determine the applica- 1
18 ·log
η
X
bility of regulatory limitations prior to use.
2
2 8
D 5 310 (1)
2
p 2 p u t
~ !
s f
2. Referenced Documents
where:
2
2.1 ASTM Standards:
η = viscosity of the fluid, cP,
C242 Terminology of Ceramic Whitewares and Related
X = distance from the middle of the centrifugal disc cell to the point
1
Products
in the cell where sedimentation starts,
X = distance from the center of the centrifugal disc cell to the point
2
3. Terminology
where the light beam intersects the particle
t = time for the particle to settle, s
3.1 Definitions—Refer to Terminology C242 for definitions
3
ρ = particle density, g/cm ,
s
of terms used in this test method.
3
ρ = fluid density, g/cm , and
f
u = rotational angular velocity, rad/s.
4. Summary of Test Method
4.1 A homogeneous aqueous dispersion of the powder is 4.2 The instruments that have been found suitable for this
prepared. While kept in a thoroughly mixed condition, a small test method incorporate microcomputers that control instru-
ment operation and perform all required data acquisition and
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This test method is under the jurisdiction of ASTM Committee C28 on computation functions.
Advanced Ceramics and is the direct responsibility of Subcommittee C28.03 on
Physical Properties and Non-Destructive Evaluation.
5. Significance and Use
Current edition approved Jan. 1, 2008. Published January 2008. Originally
approved in 1994. Last previous edition approved in 2006 as C1282 – 00 (2006).
5.1 Manufacturers and users of advanced ceramic powders
DOI: 10.1520/C1282-08.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or will find this test method useful for determining the particle
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
size distribution of these materials for product specification,
Standards volume information, refer to the standard’s Document Summary page on
quality control, and research and development.
the ASTM website.
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C1282 − 08
6. Apparatus inserting the ultrasonic transducer into the dispersing liquid/
sample in a beaker. Ensure that the transducer is approximately
6.1 Centrifugal Particle Size Distribution Analyzer —The
10.0 mm above the bottom of the sample beaker. Apply the
analyzer shall incorporate a centrifuge capable of subjecting an
ultrasonic energy at 40 W or higher for 1.0 min, and allow the
homogeneous dispersion of the sample to centr
...