Abstract | It is recognized that electrostatic charging can affect the flowability of powders. Tribocharging is generally associated with the exchange of electrons during friction between dissimilar materials. While charging is usually more important for nonconductive materials, it has been observed that electrostatic (i.e., coulombic) forces can also affect the flow of metallic powders. Tribocharging may be associated with powder handling but may also arise during the characterization and processing of the powders. Interparticle interactions are affected by charge distribution (i.e., the attraction coming from particles having different polarities) that is difficult to measure experimentally. Powder flowability and rheology have recently been used to demonstrate the effect of coulombic forces on particle interaction and flowability. This paper presents an evaluation of the effect of tribocharging on the rheology of different metallic powders (Inconel 718, Al-Mg, Ti-6Al-4V, SS-316L, and glass). Results show that charging is dependent of the nature of the materials in contact. In some cases, the effect of charging can be significant and affect the rheology of the powders. |
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