The effect of focused ultrasonic power on particles produced by the ultrasonic-assisted electrical discharge process

Metallic micro-powder mixed nanoparticles are applied as original materials in additive manufacturing (AM) and powder sintering because of the thermodynamic size effect of nanoparticles. Mechanical properties can be improved by using high density powder. The ultrasonic-assisted electrical discharge is a green and easily controlled method to generate mixed metallic powder. A new lab-made device was designed and experiments were carried out to investigate the influence of focused ultrasonic power on the dense degree and size distribution of particles. It is found that nickel particles with larger size and higher dense degree were generated by the high-density ultrasound-assisted process. The ultrasonic shock wave generated an instantaneous great force and high temperature to lead the collision and sinter between particles, which results in forming a sinter neck between particles with a large size. Meanwhile, the size and dense degree of particles increased with the increase of sound intensity.