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ASTM C1730-17
Standard Test Method for Particle Size Distribution of Advanced Ceramics by X-Ray Monitoring of Gravity Sedimentation
Přeložit název
NORMA vydána dne 1.7.2017
Informace o normě:
Označení normy: ASTM C1730-17
Poznámka: NEPLATNÁ
Datum vydání normy: 1.7.2017
Kód zboží: NS-688006
Počet stran: 4
Přibližná hmotnost: 12 g (0.03 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Kategorie - podobné normy:
Anotace textu normy ASTM C1730-17 :
Keywords:
advanced ceramics, gravity sedimentation, particle size distribution, silicon carbide, silicon nitride, zirconium oxide,, ICS Number Code 81.060.30 (Advanced ceramics)
Doplňující informace
| Significance and Use | ||||||||||||||||||||||||||||||||||||||||||||||||||
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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,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. |
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| 1. Scope | ||||||||||||||||||||||||||||||||||||||||||||||||||
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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:
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
1.2 The procedure described in this test
method may be applied successfully to other ceramic powders in this
general size range, provided that appropriate dispersion procedures
are developed. It is the responsibility of the user to determine
the applicability of this test method to other materials. Note
however that some ceramics, such as boron carbide and boron
nitride, may not absorb X-rays sufficiently to be characterized by
this analysis method.
1.3 The values stated in cgs units are to be regarded as the standard, which is the long-standing industry practice. The values given in parentheses are for information only. 1.4 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. Specific hazard information is given in Section 8. 1.5 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. |
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