Modified Scheil equation for the Cu-Sn system and comparison of hardness and electrical conductivity of Cu-8.5wt% Sn alloy directionally solidified

Abstract

The Scheil equation, which estimates the concentration of solute in the solid at the solid/liquid interface, does not account for the curvatures of liquidus and solidus lines. We modified the equation to account for these curvatures and compared some microsegregation indexes obtained by the original and the new equations with data from the literature about the Cu-Sn system. The new one can furnish a better approximation of the range of concentration of solute, but a poorer estimate of the maximum volume fraction of the eutectoid mixture. At last, we compared the hardness and electrical conductivity of an upward solidified alloy of this system with its equivalent commercial one. The as-cast alloy has a lower hardness and a higher conductivity due to its columnar structure.