Mechanical and Structural Characterization of Zn-Ti Colored Coatings

Hot dip galvanizing is one of the most popular processes used to protect steel against corrosion. It produces a coating characterized by intermetallic phases with different hardness and resistance. In this work has been studied a coating provided by a zinc alloy with 0.2 wt% of titanium. Steel samples were coated for a dipping time of 3 minutes at temperatures between 560-640 °C. The high temperatures were chosen as it has been observed a color change on the surface. With this type of bath composition the coatings obtained were characterized by a considerable thickness. By means of EDX (Energy Dispersive X-ray spectroscopy) and XRD (X-ray diffraction) intermediate phases containing FeTiZn formed during the process have been identified.Indentation and impact tests were carried out to show that the ZnTi coating is better than the more used pure zinc hot dip galvanized in terms of hardness and it undergoes decay if subjected to dynamic stresses.