TiAlSi intermetallic formation and its impact on the casting processing in Al-Si alloys

The effect of titanium additions on the formation of primary TiAlSi intermetallics and resulted cast microstructure in Al-Si alloys has been studied. The precipitation temperature, growth kinetic and morphology of TiAlSi intermetallics as well as the solubility limit of Ti in Al-Si alloys were experimentally evaluated. The impact of primary TiAlSi intermetallic particles on the casting process related problems was investigated on the large scale of industrial production. The influence of Ti in the occurrence of feeding blockage and wormhole defect during ingot casting was described. The perspectives of Ti addition in Al-Si cast alloys were discussed. It is proposed that the Ti level in the most Al-Si cast alloys should be controlled within 0.10 wt.%. (C) 2010 Elsevier B.V. All rights reserved.