Flowability

Flowability, also known as powder flow is a property that defines an ability of a powdered material to flow, related to cohesion.

Powder flowability depends on many traits:
 * the shape and size of the powder particles due to intermolecular force,
 * porosity
 * electrostatic activity
 * hygroscopy
 * bulk density
 * angle of repose
 * presence of glidants
 * oxidation rate (of a metallic powder)
 * humidity

ISO 4490:2018 norm (and its precedent, ISO 4490:2014) standardizes a method for determining the flow rate of metallic powders. It uses a normalized/calibrated funnel, named Hall flowmeter.