|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Defects and Properties of Cast Metals
||Influence of Fe-rich Intermetallics on the Formation of Solidification Defects
||Chedtha Puncreobutr, Surada Chuaypradit, André Phillion, Julie L. Fife, Peter D. Lee
|On-Site Speaker (Planned)
The enrichment of iron during aluminium recycling increases the quantity of Fe-rich intermetallics formed, particularly plate-like β-Al5FeSi intermetallics. This often promotes porosity formation and hot tearing susceptibility, limiting the production yield during the casting of recycled aluminium. To better understand the influence of Fe-rich intermetallics on solidification defect formation, fast in situ synchrotron X-ray tomographic microscopy experiments were performed for a range of iron levels and grain refining conditions in a commercial Al-Si-Cu alloy. Direct observations during solidification and semi-solid deformation experiments, together with CFD simulations, reveal that β-intermetallics contribute to defect formation via several different mechanisms. The presence of β-intermetallics strongly blocks the interdendritic channels and induces porosity formation and hot-tearing tendency as a result of permeability reduction and stress concentration. These novel insights into influence of intermetallics on defect formation highlight the very complex effect of secondary phase formation on the rheology and mechanical behaviour of semi-solid microstructures.
||Planned: Supplemental Proceedings volume