動的過冷却を考慮した過共晶Al-Si合金の初晶凝固モデル Modeling of primary solidification of hypereutectic Al-Si alloy with dynamic undercooling
A simplified numerical model is proposed to simulate the crystallization behavior of facet primary crystals of a hypereutectic Al–Si alloy. The alloy is assumed to be solidified in a cooling medium which is at a given temperature, <i>T</i><sub>B</sub>. The obtained results are summarized as follows: (1) The average crystal size, <i>d</i><sub>3</sub>, decreases as cooling rate, <i>R</i>, increases. When <i>R</i> exceeds a critical level, however, <i>d</i><sub>3</sub> begins to converge to a constant value which depends on <i>T</i><sub>B</sub>. (2) The average crystal size depends on the maximum undercooling degree of the liquid phase, Δ<i>T</i><sub>LM</sub>. (3) The value of Δ<i>T</i><sub>LM</sub> is nearly equal to Δ<i>T</i><sub>m</sub> which corresponds to the undercooling degree at the apparent onset of crystallization which is detected from the cooling curve.
軽金属 47(2), 71-77, 1997-02-28
The Japan Institute of Light Metals