Ionic Liquid The Electrodeposited Zinc Titanium Alloy

Ionic liquid with energy saving, environment friendly, high solubility and selectivity characteristics played an important role in electrochemical deposition of metals as a new type of green solvent.In this paper, deep eutectic based ionic liquid was synthesized with zinc chloride and urea, and its physical properties such as melting point, conductivity, viscosity were determined. The relationship among melting point and composition, conductivity and composition, electrical conductivity and temperature as well as the viscosity and temperature were investigated. The result indicated that, in the Urea-ZnCl2 eutectic solvent type ionic liquid, the system reached the lowest eutectic point of 20℃when XZnCl2 equals to 0.25.The conductivity of Urea-ZnCl2 ionic liquid increases with the increase of the XZnCl2 when XZnCl2<0.25, whereas the conductivity of Urea-ZnCl2 ionic liquid decreases with the increase of the XZnCl2 when XZnCl2>0.25. The conductivity of Urea-ZnCl2 ionic liquid is highest when XZnCl2=0.25. The conductivity of Urea-ZnCl2 deep eutectic based ionic liquids increases rapidly with the increasing of temperature and the viscosity is adverse. Moreover, electrical conductivity further increases with containing TiCl4. Both conductivity and viscosity of ionic liquids could be described with Arrhenious equation: Where k is electrical conductivity in S/ m,k0,η0 is pre-exponential factor, R is gas constant in 8.314 J·K-1·mol-1,is activation energy for conduction and Eηis activation energy for viscous flow in kJ/mol.The electrochemical window of Urea-ZnCl2 ionic liquid was determined, the electrochemical window was 2.4 V compared to Pt electrode, which the anodic limit potential was +1.2V and the cathodic one was -1.2V.The process of the Zn-Ti alloys electrodeposition on copper substrates from Urea-ZnCl2 ionic liquid was studied by the cyclic valtammetry. The result indicated that the cathodic electrode process is quasi-reversible process.In this article, the deep eutectic based ionic liquid Urea-ZnCl2 used as the electrolyte which electrodeposition of Zn-Ti alloys, the effect of process variables such as substrate materials, temperature and so forth on current efficiency, composition and morphology of Zn-Ti alloys, set the single-factor electrolysis conditions, and the layers were analyzed by XRD, SEM and EDS and other test methods. Finally, we obtained as follows:At low applied voltage, current density, temperature (1.3V,1.0mA·cm-2,60℃), leads to uniform paticle size, independent, but leads to lower productivity, In contrast, at high applied voltage, current density, temperature (1.8～2.0V 5.0mA·cm-2,80～90℃), obtain larger particle size, the most smooth, good adhesion, the best surface morphology of electrodeposited layer; it is easy to form large grains, serious dendrites and poor adhesion when they too high (2.2V,100℃)...