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.