Effects of Irradiation by CO2-Laser on the Alloying of Zn/Ni Double Coated Films

A new method of Zn-Ni alloy coating has been developed in which Zn/Ni double coated films were electroplated onto steel substrates, and then irradiated by a high-power CO2-laser to alloy the Zn/Ni.Alloying conditions of the laser-irradiated films were then examined. X-ray diffraction analysis revealed that the irradiated films were of the Ni5Zn21 (γ-phase) structure. EPMA line analysis showed that the surface of the irradiated films was produced by diffusion from the Ni in the underlying film to the surface of the Zn overlying film.This demonstrated the utility of alloying Zn/Ni double coated films by CO2-laser irradiation.