定向凝固μ-PD法的研究进展

Research Progress of Micro-pulling-down Method

各种定向凝固方法中Micro-pulling-down(μ-PD)法发展很快,生长出的纤维的晶体组织、物理性能和光学性能较好。介绍了μ-PD法的特点、基本原理、溶质分凝特性、凝固组织及其制备的纤维晶体性能,针对μ-PD法在金属熔体生长时弯月面不稳定而使晶体表面出现不光滑的问题,提出了采用恒定磁场调节使弯月面稳定的改进措施。

Micro-pulling-down method （μ-PD） is a new directional solidification technique and developed for the growth of fiber crystals characterized with crystal microstructures, excellent mechanical and functional properties. The features and mechanism of micro-pulling-down method, solute redistribution, grown microstructure and fiber crystal properties are illustrated and discussed. Considering the instability of meniscus in micro-pulling-down method leading to facet formation in grown fiber crystals, a permanent magnetic field imposed on the meniscus that can maintain the fiber crystals growth stable with good quality surface are presented.