The Importance of Solute-Induced Interdendritic Fluid Flow in Macrosegregation

Abstract

Experimental studies have been conducted on alloys of the tin-gallium system in order to evaluate the relative contributions of the inverse segregation, solute pushing, and solute induced fluid flow mechanisms to macrosegregation during directional solidification. Alloys that were calculated to either expand or contract during the solid–liquid transformation were solidified upwards and downwards. The patterns of solute redistribution indicate that the effect of soluteinduced fluid flow on macrosegregation is exceedingly small in this system. The implications of these observations with respect to current theories of macrosegregation in ingots are discussed.