Flow characteristics of fine metal powders are important in filling dies for pressing of powder metallurgy compacts, which are later sintered and sometimes machined into finished parts. The flow rate, as measured by a new ASTM standard, determines the flow necessary for a precise quantity of powder to be introduced into the die.

“The B964 test method has already proved useful in measuring the flow characteristics of several relatively fine tungsten powders, with excellent precision,” says Frank Venskytis, former standards manager, Global Tungsten & Powders Corp., and a member of Committee B09. He also notes that B964 will serve as a complement to B213, Test Method for Flow Rate of Metal Powders, when B213 cannot be used due to fine powders not flowing through the small-orifice Hall funnel. The Carney funnel has an orifice twice the diameter of the Hall.

According to Venskytis, in future revisions of B964, the subcommittee plans to develop a reference powder for calibration of the Carney flow apparatus. All interested parties are invited to join in the effort to develop this reference powder, as well as to participate in interlaboratory studies to develop a precision and bias statement for B964.  

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