Change Rules of Γ2 Particles in Hot-dipped Zn-Ti Coating Original Research Article

Hot-dip Zn-Ti galvanizing can restrain the excess growth of the coating which has better corrosion resistances than hot-dip pure Zn. The change rules of Γ2 intermetallic compound in hot-dip Zn-Ti galvanizing is investigated by immersion time, titanium content and the slag test using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). And the mechanism of nucleation and growth of Γ2 intcrmctallic compound is analysed. The results show that, when adding 0.05mass% titanium to the zinc bath, the Γ2 particles form in the η layer, which nucleate by obtaining Ti atoms from the η phase and Fe atoms from the dissolving ζ phase layer. Moreover, the more titanium is added into the bath, the more and bigger Γ2 particles appear. The Γ2 particles in the coatings grow up noticeably with prolonging the immersion time.