Modeling and experimental validation of deagglomeration of ultrafine nanoparticles in liquid al during noncontact ultrasonic casting of Al–Al₂O₃ Nanocomposite

Noncontact ultrasonic casting of nanocomposite has advantages over the contact method. Some of the advantages are (a) relatively uniform intensity of ultrasonic wave within the mold and (b) no dissolution of metal from the probe into the liquid metal. It also has disadvantages over the contact method. Since the ultrasonic action and cooling cum solidification occur simultaneously one needs to ensure completion of deagglomeration before the initiation of solidification. In the current study mathematical models of mold cooling cum solidification and deagglomeration have been developed to identify correct conditions for the noncontact ultrasonic casting. Using this approach a combination of casting parameters that will ensure complete deagglomeration of nanodispersoid was identified and Al–Al₂O₃ nanocomposite, in which Al₂O₃ nanoparticles are separated from each other, was successfully cast using noncontact ultrasonic casting.