Formation and capturing of nanoparticles in Cu-1wt. %Fe alloy melt during directional solidification process

Abstract

A single crystal Cu-1wt. %Fe alloy with finely dispersed iron-rich nanoparticles which keep coherent interface with the copper matrix was prepared under directional solidification. Formation of nanoparticles in the alloy melt was investigated by performing differential scanning calorimeter tests and designed water quenching experiment at a certain temperature. Results show that iron-rich nanoparticles are formed in the Cu-1wt. %Fe alloy melt before primary α-Cu forms, which is not consistent with equilibrium phase diagram. Mechanism that iron-rich nanoparticles are uniformly captured in the matrix was described, which is that numerous nanoparticles follow Brownian motions and are engulfed in the solidified matrix which makes it possible to form uniformly distributed nanoparticles reinforced single crystal Cu-1wt. %Fe alloy.