Thermodynamics Properties of Ternary Bath of Coloring Hot--Dip Galvanization
三元系彩色热镀锌镀液的热力学性质

The activities and activity interaction parameters of two kinds of ternary alloy baths, Zn-Mn-Me and Zn-Ti-Me, were calculated by using an integral model and an analytic expression of activity coefficient. The results indicate that the activity of color generation element Mn or Ti was increased as adding Ni or Cu, where the effect of Ni is superior to Cu, however, Ti decreased the activity of Mn in Zn-Mn bath, and existed the opposite behavior for Mn in Zn-Ti. There is an inevitable relationship between the activity of components and color generation effectiveness. That is to say, the elements which can increase the activities of color generation elements would be in favor of improving the combination properties of hot-dip bath, and finally improving color generation effectiveness. Therefore, Mn, Ni, and Cu are favorable elements for coloring hot-dip bath, and the advantages and disadvantages of Ti are related with its concentration, which is consistent with the results of technology experiments.