Influence of Growth Rate on the Solute Distribution of Directionally Solidified Cu-Ag-Zr Alloy

Abstract

Cu-2wt.Ag-2wt.%Zr alloy was directionally solidified with different growth rates(V=10-200 um/s) at a constant temperature gradient(G=3.1 K/mm) in a modified Bridgman furnace. The influence of growth rate was investigated by observing the microstructure and measuring the solutes’ compositions within the Cu-matrix and dendrite boundaries. The experimental results show that increasing the growth rate, decreased both the primary and secondary arm spacing and increased micro-Vickers hardness. The solutes’ concentration also increased as a result of the back diffusion caused by a decreasing growth rate. The electrical conductivity depends on the solutes’ distribution.