Shear Induced Grain Refinement of a Continuously Cast Ingot

In previous investigation [1] has demonstrated the wide variation of grain size found through the cross-section of a Direct-Chill ( DC) cast ingot due to the location-dependent solidification rate inherent to the process. Recently we have demonstrated [2] that the use of a turbulent jet as a metal entrance method has the potential to significantly reduce grain size and its variability upon location. We herein report a series of experiments investigating the influence of jet power on the grain size and distribution in Al4.5Cu DC cast ingots. Our findings indicate that significantly increasing the jet power does not appreciably decrease the grain size. Instead, a threshold jet power required for grain refinement is anticipated, beyond which only marginal improvements are anticipated.