Tribochemical applications of high-intensity ultrasound: Sonochemical production of intermetallic coatings in heterogeneous media

An energy-dispersive X-ray (EDX) study of binary mixtures of mixed composition metal powders exposed to high-intensity ultrasound in decane indicates that metal particles are fused hy the action of ultrasound and develop intermetallic coatings. The principal mechanism behind both processes is interparticle collision caused by the rapid movement of particles propelled by Shockwaves generated at cavitation sites. By examination of systems with differing metallurgical compatibilities (Ni/Co, Cu/Cr, and Cu/Mo), it has been determined that the intermetallic coatings are generated by both adhesive wear and direct impact. The mechanisms of ultrasound-induced coatings are discussed.