ASTM C925-09(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C925 − 09 (Reapproved 2019)
Standard Guide for
Precision Electroformed Wet Sieve Analysis of Nonplastic
Ceramic Powders
This standard is issued under the fixed designation C925; 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. Significance and Use
4.1 Both suppliers and users of pulverized ceramic powders
1.1 This guide covers the determination of the particle size
will find this test method useful to determine particle size
distribution of pulverized alumina and quartz for particle sizes
distributions for materials specifications, manufacturing
from 45 to 5 µm by wet sieving.
control, development, and research.
1.2 The values stated in SI units are to be regarded as
4.2 The test method is simple, although tedious, uses
standard. No other units of measurement are included in this
inexpensive equipment, and will provide a continuous curve
standard.
with data obtained with standardized woven sieves.
1.2.1 The only exception is in the Section 5,Apparatus, 5.1
where there is no relevant SI equivalent.
5. Apparatus
1.3 This standard does not purport to address all of the
5.1 Precision Electroformed Sieves , 3-in., mounted in brass
safety concerns, if any, associated with its use. It is the
frames, having nominal apertures of 45, 30, 20, 10, and 5 µm
responsibility of the user of this standard to establish appro-
andasupportgridhaving5.7linespercentimetre.Intermediate
priate safety, health, and environmental practices and deter-
sizes may also be used.
mine the applicability of regulatory limitations prior to use.
5.2 Sieving Device (Fig. 1):
1.4 This international standard was developed in accor-
5.2.1 Filtering Flask (suction flask), 1-L, with side arm,
dance with internationally recognized principles on standard-
5.2.2 Büchner Funnel (for example, Coors No. 2),
ization established in the Decision on Principles for the
5.2.3 O-Ring, 7.5-cm, rubber,
Development of International Standards, Guides and Recom-
5.2.4 Graduate, 1-L,
mendations issued by the World Trade Organization Technical
5.2.5 Rubber Stoppers, one-hole to fit the flask and the
Barriers to Trade (TBT) Committee.
funnel, two-hole to fit the graduate,
5.2.6 Quantity of glass tubing and rubber tubing,
2. Referenced Documents
5.2.7 Metal Rod, 15 to 20-cm, about 5 mm in diameter, and,
2.1 ASTM Standards: 5.2.8 Vacuum Source.
E161 Specification for Electroformed Material and Test
5.3 Ultrasonic Cleaner, required to clean all sieves below
Sieves
20 µm. It should be low-powered (for example, 100 W).
5.4 AnalyticalBalance,capableofweighingupto100gand
3. Summary of Guide
having at least three significant digits after the decimal.
3.1 A separate dispersed suspension of the powder is wet
5.5 Drying Oven, capable of maintaining 110 6 5 °C.
sieved through each sieve, using vacuum and vibration. The
5.6 Desiccator, containing magnesium perchlorate or other
sieve and sample are dried and weighed.
suitable desiccant.
6. Reagents and Materials
This guide is under the jurisdiction of ASTM Committee C21 on Ceramic
6.1 Water, visually clear and particle free, not necessarily
Whitewares and Related Productsand is the direct responsibility of Subcommittee
distilled, at room temperature or slightly above.
C21.04 on Raw Materials.
Current edition approved Oct. 1, 2019. Published October 2019. Originally
6.2 Sieving Solution, a dispersing media consisting of 0.1
approved in 1979. Last previous edition approved in 2014 as C925 – 09 (2014).
weight % solution of sodium hexametaphosphate or sodium
DOI: 10.1520/C0925-09R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or pyrophosphate in water.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.3 Drying Agents, acetone or methyl alcohol, commercial
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. grade.
*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
C925 − 09 (2019)
within the quoted 2-µm tolerance. The calibration procedure is
given in Appendix X1 of Specification E161.
10. Procedure
10.1 Wash the sieves with the sieving solution, rinse with
water and then with the drying agent, dry at 110 °C for 15 min,
cool in the desiccator, and weigh to at least the nearest 1 mg.
10.2 Sample Size is somewhat dependent upon density, but
the following schedule is satisfactory for alumina and quartz:
Nominal Sieve Sample Weight
Apertures, µm (approximate), g
45, 30, 20 1.0
15, 10 0.4
5 0.15
10.3 Weigh the required amount of sample into a 100-mL
beaker, fill half with sieving solution (containing the dispersing
agent), and disperse by placing beaker in ultrasonic bath for 1
min. Microscopical examination of the particles after disper-
sion may be helpful in determining if the dispersion is
complete.
10.4 Wash the dispersed sample onto the sieve using a wash
bottle containing the sieving solution, turn on vacuum
...