Rapid eutectic growth of Al₂O₃/Er₃Al₅O₁₂ nanocomposite prepared by a new method: Melt falling-drop quenching

A novel melt falling-drop quenching method with rapid cooling rate is carried out to prepare the Al₂O₃/Er₃Al₅O₁₂ nanoeutectic ceramic based on laser floating zone melting. The regular eutectic structure with minimum interphase spacing of 30 nm is obtained, which is much smaller than previous reports. The continuous transition of irregular eutectic to regular eutectic and to amorphous structure is found under rapid solidification, and the instability mechanism of eutectic growth is discussed. On the basis, the corresponding eutectic growth rate during rapid solidification, which is calculated by Jackson-Hunt model and Trivedi-Magnin-Kurz model, is between 8.65 μm/s ~ 5.32 × 10⁴ μm/s.