Article ID Journal Published Year Pages File Type
1259046 Journal of Rare Earths 2015 8 Pages PDF
Abstract

The Al-5Ti-0.2C-based grain refiners with different contents of rare earth (RE) were successfully prepared via powder metallurgy and vacuum casting. The microstructural evolution has been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the RE addition resulted in the formation of TiAl3/Ti2Al20RE core-shell structured primary particles, and the size of TiAl3 core decreased, while the thickness of Ti2Al20RE increased with increase of RE contents. As compared to Al-5Ti-0.2C grain refiner, the grain refining efficiency was gradually improved with increase of RE contents, which was mainly attributed to the TiAl3/Ti2Al20RE core-shell structured primary particles and insoluble TiC nuclei formed in a-Al matrix. The formation mechanism of core-shell structure was further investigated based on Ginstling-Brounstein model.

Graphical abstractSEM images and line scan elemental profiles across the primary particle of Al-5Ti-0.2C-3.0RE (a, b)Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Chemistry (General)
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