NUCLEATION BEHAVIOR OF Al_8Fe_4Nd PHASE IN RAPIDLY SOLIDIFIED Al-Fe-V-Si-Nd ALLOY

摘要

The microstructure of Al-Fe-V-Si-Nd alloy prepared by rapid solidification (RS) processing was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The phase selection of the alloy during solidification and the nucleation behavior of Al_8Fe_4Nd phase were analyzed within the framework of time-dependent nucleation theory. The incubation time for Al_8Fe_4Nd phase was found shorter and the nucleation rate higher than those of alpha-Al. The results indicate the nucleation of Al_8Fe_4Nd phase is heterogeneous and the dispersoids of Al_8Fe_4Nd form as primary particles from the liquid, which is consistent with experimental observation.