A powder deagglomerator includes a vertical flow chamber, a powder inlet tube, and an ultrasonic horn vibrationally coupled to an ultrasonic transducer. The vertical flow chamber includes an outer wall, powder outlet port, and a mounting port sealably engaging an ultrasonic horn. The powder inlet tube extends through the outer wall and is aligned to dispense agglomerated powder in a gaseous stream downward onto a distal end of the ultrasonic horn. A method of using the powder deagglomerator to deagglomerate a powder is also disclosed.