Microstructure and refining performance of an Al-5Ti-0.25C refiner before and after equal-channel angular pressing

Refining experiments were conducted to evaluate the grain refining performance of an Al-5Ti-0.25C refiner before and after equal-channel angular pressing (ECAP) with the use of a high-purity Al. The results show that the Al-5Ti-0.25C refiner has remarkable and stable grain refining performance when the holding times are within 5 to 30 minutes and the melt temperatures are within 1003 to 1073 K. Furthermore, some Al-5Ti-0.25C refiner samples were subjected to severe plastic deformation by using the ECAP technique at 298 K. It was found that Al^sub 3^Ti and TiC particles were significantly fragmented and their mean sizes were decreased to 10 and 1.08 µm, respectively, and the Al-5Ti-0.25C refiner appeared to have a double grain refining effect in comparison with that of before ECAP. It is also testified that the Vickers microhardness (Hv) value of the pure Al samples refined by the Al-5Ti-0.25C refiner after ECAP processing has a significant increment than that of before ECAP processing. It is concluded that the Al-5Ti-0.25C refiner with ECAP technique has a very useful practical application in refining industrial Al alloys. [PUBLICATION ABSTRACT]