ASTM C1282-00

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Designation:C 1282–00
Standard Test Method for
Determining the Particle Size Distribution of Advanced
1
Ceramics by Centrifugal Photosedimentation
This standard is issued under the fixed designation C 1282; 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 4. Summary of Test Method
1.1 This test method covers determination of the particle 4.1 A homogeneous aqueous dispersion of the powder is
size distribution of advanced ceramic powders specifically prepared. While kept in a thoroughly mixed condition, a small
silicon nitride and carbides, in the range of 0.1 to 20 µm, aliquot is transferred to the analyzer sample cell, which is
having a median particle diameter from 0.5 to 5.0 µm. placed in the instrument and subjected to a controlled centrifu-
1.2 The procedure described in this test method may be gal acceleration at a known or controlled temperature. At
applied successfully to other ceramic powders in this general predetermined times related to the sedimentation of specific
size range, provided that appropriate dispersion procedures are Stokes’ diameters (Note 1), the optical absorbance is recorded
developed. It is the responsibility of the user to determine the and compared to the initial value to determine the fraction of
applicability of this test method to other materials. the total sample that has sedimented a specific distance. A
1.3 The values stated in SI units are to be regarded as the volume-based size distribution is calculated from the
standard. The values given in parentheses are for information absorbance-time data. The results are reported as equivalent
only. diameter (spherical) (Note 2) since particles in these powders
1.4 This standard does not purport to address all of the are not truly spherical.
safety concerns, if any, associated with its use. It is the
NOTE 1—This diameter in µm is referred to as D in the equation given
responsibility of the user of this standard to establish appro-
below.
priate safety and health practices and determine the applica-
NOTE 2—Refer to Terminology C 242 for the ASTM definition of this
bility of regulatory limitations prior to use.
term. Most equipment manufacturers refer to this as the equivalent
spherical diameter.
2. Referenced Documents
X
1
2
18 · log
h
2.1 ASTM Standards:
X
2
2 8
D 5 3 10 (1)
2
C 242 Terminology of Ceramic Whitewares and Related
~p – p !u t
s f
Products
where:
E 177 Practice for Use of the Terms Precision and Bias in
h = viscosity of the fluid, cP,
ASTM Test Methods
X = distance from the middle of the centrifugal disc cell to the point
1
E 691 Practice for Conducting an Interlaboratory Study to
in the cell where sedimentation starts,
Determine the Precision of a Test Method
X = distance from the center of the centrifugal disc cell to the point
2
where the light beam intersects the particle
3. Terminology
t = time for the particle to settle, s
3
r = particle density, g/cm ,
3.1 Definitions—RefertoTerminologyC 242fordefinitions s
3
r = fluid density, g/cm , and
f
of terms used in this test method.
u = rotational angular velocity, rad/s.
1
This test method is under the jurisdiction of ASTM Committee C28 on
4.2 The instruments that have been found suitable for this
Advanced Ceramics and is the direct responsibility of Subcommittee C28.03 on
test method incorporate microcomputers that control instru-
Physical Properties and Performance.
ment operation and perform all required data acquisition and
Current edition approved Oct. 10, 2000. Published January 2001. Originally
published as C 1282 – 94. Last previous edition C 1282 – 94. computation functions.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
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C 1282–00
5. Significance and Use 8.1.1.1 Sample Dispersion—Place the beaker containing
sample in an ice water bath so that the temperature of the
5.1 Manufacturers and users of advanced ceramic powders
sample does not exceed approximately 30°C.Adjust the pH of
will find this test method useful for determining the particle
the sample to 9.06 0.2 to ensure adequate dispersion aided by
size distribution of these materials for product specification,
the chemical environment. Deagglomerate the sample by
quality control, and research and development.
inserting the ultrason
...