The influence of TiB2 particles on the effectiveness of Al-3Ti-0.15C grain refiner

This work deals with the influence of TiB2 particles already present, and added in the form of Al-5Ti-1B grain refiner, on the effectiveness of Al-3Ti-0.15C grain refiner in an Al-Fe alloy. We found that Al-3Ti-0.15C grain refiner is ineffective in the case of the addition of both Al-5Ti-1B and Al-3Ti-0.15C grain refiners to an Al-Fe alloy. Despite the presence of TiB2 particles in the Al-Fe alloy, Al-3Ti-0.15C grain refiner is, however, effective when added on its own to an Al-Fe alloy. The effectiveness and ineffectiveness of Al-3Ti-0.15C grain refiner with Al-Fe alloys were also confirmed by the presence of TiC particles and TiB2 particles in the centres of the alpha-Al grains. Recalescence on solidification measured by in-situ thermal analysis can explain the effectiveness and ineffectiveness of Al-3Ti-0.15C grain refiner in Al-Fe alloys. (C) 2008 Elsevier Inc. All rights reserved.