Experimental Zn-rich corner of the Fe-Zn-Cu ternary phase diagram at 460 °C

The zinc-rich corner of the Fe-Cu-Zn ternary system diagram at 460°C was investigated. Two low-carbon steel substrates were prepared where the first substrate was rolled with a copper wire. A copper piece was hammered in the middle of the second one to make a rivet. The samples were then batch galvanized at 460°C for one hour in a zinc bath saturated with iron and added with 2.9% at Cu. The two specimens were either air cooled or water quenched. The microstructure of the coatings was characterized by scanning electron microscopy and analyzed by energy dispersive spectroscopy. All the chemical compositions were then reported in the isothermal section at 460°C of the Fe-Cu-Zn ternary phase diagram. A succession of phases in equilibrium were observed between copper, steel and the other galvanized layer. Moreover, various equilibria between different phases with specific compositions were found.