ASTM B761-17(2021)
Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation

Standard No.

ASTM B761-17(2021)

Release Date

2021

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM B761-17(2021)

Scope

1.1 This test method covers the determination of particle size distributions of metal powders. Experience has shown that this test method is satisfactory for the analysis of elemental tungsten, tungsten carbide, molybdenum, and tantalum powders, all with an as-supplied estimated average particle size of 6 µm or less, as determined by Test Method B330. Other metal powders (for example, elemental metals, carbides, and nitrides) may be analyzed using this test method with caution as to significance until actual satisfactory experience is developed (see 7.2). The procedure covers the determination of particle size distribution of the powder in the following two conditions: 1.1.1 As the powder is supplied (as-supplied), and 1.1.2 After the powder has been deagglomerated by rod milling as described in Practice B859. 1.2 This test method is applicable to particles of uniform density and composition having a particle size distribution range of 0.1 up to 100 µm. 1.2.1 However, the relationship between size and sedimentation velocity used in this test method assumes that particles sediment within the laminar flow regime. This requires that the particles sediment with a Reynolds number of 0.3 or less. 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 with Reynolds number greater than 0.3 if particles greater than 25 µm 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 flowing equation Re 5 D3 ~ρ 2 ρ0!ρ0g 18η2 (1) where D = the diameter of the largest particle expected to be present, ρ = the particle density, ρ0 = the suspending liquid density, g = the acceleration due to gravity, and η = is the suspending liquid viscosity. A table of the largest particles that can be analyzed with Reynolds number of 0.3 or less in water at 35°C is given for a number of metals in Table 1. A column of the Reynolds number calculated for a 30–µm particle sedimenting in the same liquid system is given for each material also. 1.3 Units—With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimetre (g/cm3 ) and gram (g) units is the longstanding industry practice, the values in SI units are to be regarded as standard. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard information is given in Section 7. 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.

ASTM B761-17(2021) Referenced Document

• ASTM B330 Standard Test Method for Fisher Number of Metal Powders and Related Compounds*， 2024-04-21 Update
• ASTM B821 Standard Guide for Liquid Dispersion of Metal Powders and Related Compounds for Particle Size Analysis
• ASTM B859 Standard Practice for De-Agglomeration of Refractory Metal Powders and Their Compounds Prior to Particle Size Analysis
• ASTM E456 Standard Terminology for Relating to Quality and Statistics
• ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

ASTM B761-17(2021) history

• 2021 ASTM B761-17(2021) Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 2017 ASTM B761-17 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 2011 ASTM B761-06(2011) Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 2006 ASTM B761-06 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 2002 ASTM B761-02e1 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 2002 ASTM B761-02 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation
• 1998 ASTM B761-98 Standard Test Method for Particle Size Distribution of Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation