Experimental determination of solid-solid and solid-liquid interfacial energies of solid epsilon (CuZn_5) in the Zn-Cu alloy

摘要

The equilibrated grain boundary groove shapes of solid e (CuZn_5) in equilibrium with Zn-1.75 at. percent Cu peritectic liquid and solid e (CuZn_5) in equilibrium with solid Zn solution (Zn-2.83 at. percent Cu) were observed from a quenched sample. The Gibbs-Thomson coefficient solid-liquid interfacial energy and grain boundary energy of solid s (CuZn_5) in equilibrium with Zn-1.75 at. percent Cu peritectic liquid have been determined to be (4.9+-0.3) X 10~(-8) Km, (76.0+-9.1) X 10~(-3) J m~(-2) and (150.3+_19.5) X 10~(-3) J m~-2), respectively. For the first time, the equilibrated grain boundary groove shapes of solid epsilon (CuZn_5) in equilibrium with solid Zn solution have been observed. The Gibbs-Thomson coefficient, solid-solid interfacial energy and grain boundary energy of solid s (CuZns) in equilibrium with solid Zn have also been determined to be (4.7+-0.3)X 10~(-8)Km, (72.9+-8.7)X 10~(-3) J m~(-2) and (144.1+-18.7)X 10~(-3) J m~(-2), respectively from the observed grain boundary groove shapes. The thermal conductivities of solid Zn solution and solid e (CuZn_5) phase (Zn-12 at. percent Cu) have been measured with radial heat flow apparatus. The thermal conductivity ratios of the equilibrated liquid phase to solid phase for Zn-1.75 at. percent Cu and Zn-12 at. percent Cu alloys have also been measured with Bridgman type growth apparatus.