急冷凝固法によるAl-Pb合金の重力偏析の低減に関するコンピュータシミュレーション

抄録

The programme of this computer simulation was made by the introduction of new numerical calculation method on gravity segregation in the computer simulation on the structure solidified by rapid cooling for Al-Pb alloys. The control of the gravity segregation by rapid cooling and the formation process were investigated by the present computer simulation. A mechanism of the gravity segregation of Al-Pb alloys is considered as the falling phenomenon of growing L₂ liquid phase during the separating and coexisting reaction. The falling behavior of L₂ depended on density difference between L₁ and L₂ or growth of L₂ at elevated temperatures and the viscosity of L₁ at temperatures below about 1123 K. The rapid solidification method could decrease the gravity segregation of high lead alloys. In low lead alloys, the method was rapid in cooling enough to prevent the gravity segregation. For cooling rates of 50 K/s to 10³ K/s, the calculated condition for the prevention of the gravity segregation was in agreement with the experimental one.