単結晶Al₂O₃板を通した液体金属中のAl₂O₃粒子／単結晶Al₂O₃板間の焼結界面のその場観察

In a continuous casting process, the clogging of the immersion nozzle with inclusions occurs as a result of the adhesion, agglomeration, and coalescence of inclusions. The most effective way to understand the behavior of inclusions, i.e. oxide particles, in a liquid steel is the in-situ observation. To our knowledge, however, there is no research on the in-situ observation of the behavior of oxide particles in a liquid steel. In the present work, therefore, the in-situ observation method for sintering interface between Al2O3 particle / single crystalline Al2O3 plate by laser microscope through single crystalline Al2O3 plate is proposed. First, the in-situ observation of sintering interface between Al2O3 particle and single crystalline Al2O3 in Ar atmosphere is conducted to verify the observation method for the interface through single crystalline Al2O3 plate. Then, the in-situ observation of sintering interface between Al2O3 particle and single crystalline Al2O3 in a liquid Ag is challenged. The observations for sintering interface between Al2O3 particle and single crystalline Al2O3 plate in Ar gas atmosphere and a liquid Ag are achieved by our proposed method. It is verified that the growth of sintering interface in liquid Ag is faster than that in an Ar gas atmosphere. This finding indicates that the non-wetting by liquid Ag of alumina particles promotes the growth of sintering interface in liquid Ag.