Microstructure of hot-dipped Zn-Ti-Al coating

摘要

In order to study the effect of Ti、Al addition on microstructure of hot-dip zinc coatings, the Zn-Ti-Al alloy coatings were galvanized by the hot-dip method in zinc baths containing aluminum and titanium.The coatings were examined with scanning electron microscopy (SEM) equipped with EDS analyzer.The results indicated that the addition of 0.04％ Ti, 0.04％ Ti + 0.02％ Al could suppress the growth of ζ phase in the coating, therefore, compact ζ layer was found, and both ζ layer thickness and alloy layer thickness were greatly reduced.While dipping in the Zn-0.04％ Ti-0.02％ Al bath for 60 s, T phase composed of Zn, Fe, Ti, Al forms at the interface between ζ layer and Zn overlay.While dipping in the Zn-Ti-Al bath for 240 s, block T phase or T phase islet was found at the ζ/η interface or in η phase region.