摘要
A novel semi-solid slurry-making process was developed, which was a controlled nucleation and growth technique using a specially designed rotational barrel. Experimental study was undertaken to investigate the effects of pouring temperature and rotation speed of barrel on the microstructure of A356 alloy. Localized rapid cooling, combined with vigorous mixing during the initial stage of solidification enhanced wall nucleation and nuclei survival. High nuclei density combined with a much gradual cooling afterwards led to the formation of the near-ideal semi-solid slurry under a large processing window for the pouring temperature. Primal. phase presented in mean equivalent diameter of 50-701μm and shape factor of 0.812-0.847, and featured zero-entrapped eutectic.
A novel semi-solid slurry-making process was developed, which was a controlled nucleation and growth technique using a specially designed rotational barrel. Experimental study was undertaken to investigate the effects of pouring temperature and rotation speed of barrel on the microstructure of A356 alloy. Localized rapid cooling, combined with vigorous mixing during the initial stage of solidification enhanced wall nucleation and nuclei survival. High nuclei density combined with a much gradual cooling afterwards led to the formation of the near-ideal semi-solid slurry under a large processing window for the pouring temperature. Primal. phase presented in mean equivalent diameter of 50-701μm and shape factor of 0.812-0.847, and featured zero-entrapped eutectic.
基金
This work was supported by the National Natural Science Foundation of China(No.50474007)
Jiangxi Provincial Natural Science Foundation of China(No.0450050)
the Science&Technology Project of Education Department of Jiangxi Province(No.GanJiaoJiZi[2005]24).
作者简介
Corresponding author. Tel.： ＋86 791 E-mail address ： hmguo_email@163.com 3969553; fax： ＋86 791 3969553 （H.M. Guo）
