离心渗铸金属铝熔液的瞬态固化与再熔

通过分析离心力场中金属铝熔液在Al2O3短纤维多孔介质内的渗流传热，考虑了离心惯性力对铝熔液的瞬态固化与再熔的影响，建立了旋转多孔介质内的渗流传热理论模型．研究了复合管铸造工艺中不同工况下液固共融区的长度和固化率的瞬态变化规律以及流场压损的分布规律．结果表明：在Al2O3颗粒的预热温度低于铝熔化温度的条件下，当渗透前沿达到一定深度时出现液固共融，随后液固共融区随渗透过程而增长，固化率逐渐提高．随着孔隙率的减小，液固共融区的长度和固化率增大，出现共熔现象的固化率降低，复合层能达到的最大厚度减小．而随着转速的减小，液固共融区长度缩短，共熔区内的固化率水乎提高，出现共熔现象的固化率增大，复合层能达到的最大厚度减小。

Molten Al infiltration and solidification/remelting in a centrifugal force field

Molten aluminum flow with heat transfer through a fibrous preform in a centrifugal force field is described in this paper. The pressure distribution in the preform and the solid volume fraction profiles are presented for difference conditions. The results show that the fiber preheated temperature, the superheat of pouring liquid metal, the fibrous volume fraction and the rotational speed of equipment are very influential on solidification and remelting in the centrifugal force field. The regional extent of eutectic solid metal and its solid volume fraction increase with the moving of infiltrated distance. An increase of rotational speed and porosity results in a decrease of the solid volume fraction, as well as the length of solidification zone during centrifugal casting process. The maximum composite layer depth increases with the rotational speed and the fibrous volume fraction.