Abstract:The Al₂O_3(p)/Al nano-composites were fabricated from Al−K₂ZrF₆−Na₂B₄O₇ system by sonochemistry in situ reaction. The fabrication mechanisms, including high intensity ultrasonic influence on microstructures and reinforcement particles-aluminum matrix interface, were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD results show that the component of the as-prepared composites is Al₂O₃ reinforcement. The SEM analysis results indicate that Al₂O₃ particles are uniformly distributed in the aluminum matrix. The TEM results show that the morphologies of Al₂O₃ particles present in nearly sphere-shape, the sizes are in the range of 20−100 nm, and the interfaces are net and no interfacial outgrowth is observed. Analysis with secondary development Image-J software shows that Al₂O₃ recoveries are firstly improved and then decreased with increasing ultrasonic power. When the power is 0.4 kW, the distribution is the best, and a maximum number of particles are obtained. The reaction mechanisms were investigated.

Key words: sonochemistry; nano-composites; in situ reaction; reaction mechanism