A new method for evaluating powder flowability using constant volume shear tester

Abstract

A new method for evaluating powder flowability is developed using a constant volume shear tester; this tester measures the upper and lower normal stresses and the shear stress acting on a powder bed. A single shear test provides a series of characteristics, such as powder yield locus (PYL), consolidation yield locus (CYL), critical state line (CSL), shear cohesion, stress relaxation ratio, stress transmission ratio, and void fraction. The values of the shear stress as a function of the normal stress and the void fraction are visualized in three-dimensional diagrams. Furthermore, powder flowability is evaluated using a flow function obtained from the PYL.