Control of microstructure and macrosegregation of large-sized aluminium alloy billet by uniform direct chill casting

摘要

By coupling annular electromagnetic stirring with intercooling, a uniform direct chill (UDC) casting process has been developed to achieve fine and uniform microstructure for the large-sized aluminium alloy billets. In this study, the solidification behaviour of phi 508 mm 7005 alloy during UDC casting process was investigated, and the effect of the processing parameters on the microstructures and segregation of the billets were examined. The results indicated that, the solidification structure could be remarkably refined in the UDC casting process, and subsurface segregation could be alleviated by adjusting the vertical position of the stirring coils.