ASTM B855-22

SIGNIFICANCE AND USE 5.1 The volumetric flow rate is a measure of the flow characteristics of a metal powder. Measuring flow by volume compared with flow per unit mass eliminates the variable of the powder density and relates to the production practice of die filling by volume. 5.2 The ability of a powder to flow and pack is a function of interparticle friction. As the surface area increases, the amount of friction in a powder mass also increases. Consequently, the friction between particles increases, giving less efficient flow and packing. 5.3 Knowledge of the volumetric flow rate permits the part producer to estimate the number of parts that can be compacted per hour. 5.4 This test may be part of the purchase agreement between metal powder producers and powder metallurgy (PM) part producers, or it can be an internal quality control test for any company using metal powders. SCOPE 1.1 This test method covers a laboratory procedure for the quantitative determination of the flow rate of a specific volume of a free-flowing metal powder or lubricated powder mixture. 1.2 Units—With the exception of the values for mass, volume, and density, for which the use of the gram and the cubic centimetre unit is long-standing industry practice, the values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 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. 1.4 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.