Microstructure of A1-5Ti-0.6C-1Ce master alloy and its grain-refining performance

Al-5Ti-0.6C-1Ce master alloy has been successfully prepared by a method of thermal explosion reaction in pure molten aluminum. The microstructure of the alloy was characterized by means of optical microscopy, X-ray diffraction and scanning electron microscopy equipped with energy-dispersive spectrometry. The results showed that the Al-5Ti-0.6C-1Ce alloy was composed of alpha-Al, granular TiC, lump-like TiAl3 and block-like Ti2Al20Ce. When compared with the Al-5Ti-0.6C master alloy, the formation of Ti2Al20Ce compounds and the addition of Ce accelerated the formation of TiC. An excellent grain-refining performance was obtained when the addition level of Al-5Ti-0.6C-1Ce reached 0.5 wt.%. The effect of Ce on the synthesis of TiC and refinement mechanism of Al-5Ti-0.6C-1Ce has also been discussed.