Ostwald ripening of rod-shaped α-Fe particles in a Cu matrix

The coarsening behavior of rod-shaped α-Fe particles in Cu–1.0 wt.% Fe and Cu–1.0 wt.% Fe–1.2 wt.% Sb alloys during aging at 700 °C has been studied by transmission electron microscopy and electric resistivity. The kinetics of the decay of supersaturation with aging time t for both alloys coincide with the t−1/3 law. The coarsening kinetics of the cylindrical radius of the Fe particles obey the t1/3 law. Using the Lifshitz–Slyozov–Wagner theory modified for the case of rod-shaped particles by Speich and Oriani, the maximum value of the Cu/α-Fe interfacial energy γ and the volume diffusivity D of Fe in Cu for the Cu−Fe alloy are independently derived to be 1.3 J/m2 and 3.9×10−16 m2/s. Adding Sb to the Cu−Fe alloy decreases the values of γ and D.