【国外标准】 Standard Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel

5.1 The rate and uniformity of die cavity filling are related to flow properties, which thus influence production rates and uniformity of compacted parts.5.2 The ability of a powder to flow is a function of interparticle friction. As interparticle friction increases, flow is slowed. Fine powders may not flow. Some powders, often fine powders and lubricated powder mixtures, may not flow through the Hall Flowmeter funnel. Nevertheless, if a larger orifice is provided, such as in the Carney Flowmeter funnel of Test Methods B964, a meaningful flow rate may be determined, providing specific information for certain applications.5.3 Test Methods B213, using the Hall Flowmeter funnel, are the preferred methods for determining the flowability of metal powders and powder mixtures. The Carney Flowmeter funnel of Test Methods B964 should only be used when powder will not flow through the Hall Flowmeter funnel.5.4 Humidity and moisture content influence flow rate. Wet or moist powders may not flow.5.5 These test methods are based on flow of a specified mass of powder. If flow of a specific volume of powder is preferred, Test Method B855 may be used for powders that flow readily through the Hall Flowmeter funnel.5.6 This test method may be part of the purchase agreement between powder manufacturers and powder metallurgy (PM) part producers, or it can be an internal quality control test by either the producer or the end user.1.1 This test method covers the determination of a flow rate, by the use of the Hall Flowmeter funnel of metal powders and powder mixtures. It is suitable only for those powders that will flow unaided through the Hall Flowmeter funnel.1.2 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 long-standing industry practice, the values 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.