Solidification and remelting of Al through Al2O3 fibrous preform under centrifugal force
(1.上海市上海交通大学机械与动力工程学院
2.School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
2.School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract: The solidification and remelting of molten aluminum through a porous preform under centrifugal force field were modeled numerically. The results show that the transient solidification and remelting phenomena appear on the infiltration front and can be divided into two distinct regions: the remelting region and solid-liquid congruent melting region. The decrease of porosity always results in the increase of moving velocity difference between the infiltration front and the remelting front, which leads to the increase of the solid-liquid congruent region extent. But for the decrease of the rotational frequency, the difference of moving velocity between infiltration front and remelting front decreases, which leads to the decrease of regional extent. The infiltration front moving velocity is mainly influenced by the centrifugal infiltration pressure, whereas the remelting front moving velocity is mainly influenced by the material thermodynamics. The transient solidification and remelting phenomena are the intercoupling results between the centrifugal infiltration dynamics and the material thermodynamics.
Key words: fibrous preform; centrifugal infiltration casting; solidification; remelting; heat transfer