Up to which temperature ultrasound can heat the particle?

Crystallographic property such as crystallite size has been used for evaluation of the temperature up to which high intensity ultrasound can heat metal particles depending on physical properties of sonication medium and particle concentration. We used >100 μm metal particles as an in situ indicator for ultrasonically induced temperature in the particle interior. Based on powder X-ray diffraction monitoring of Al₃Ni₂ crystallite sizes after ultrasound treatment the average minimum temperature T¯particlemin of sonicated particles in various sonication media was estimated. Additionally, it was found that crystallite size in ultrasonically treated metal particle depends on the frequency of interparticle collision. Through the adjustment of particle concentration, it is possible to either accelerate the atomic diffusion or force the melting and recrystallization processes. Overall, the energy released from collapsing cavitation bubble can be controllably transferred to the sonication matter through the appropriate choice of sonication medium and the adjustment of particle concentration.