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 diffracti...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 inα-Al matrix. The formation mechanism of core-shell structure was further investigated based on Ginstling-Brounstein model.展开更多
基金Project supported by National High Technology Research and Development Program of China(2013AA031001)the National Basic Research Program of China(2012CB619503)International Science&Technology Cooperation Program of China(2012DFA50630)
文摘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 inα-Al matrix. The formation mechanism of core-shell structure was further investigated based on Ginstling-Brounstein model.
