Studies On Electrodeposition Behavior Of Al-Ti Alloys In Chloroaluminate Ionic Liquids

Due to their excellent corrosion resistance, biocompatibility, high strength ratio, Al-Ti alloys have been widely used in many fields, including Ship industry, aerospace industry,automotive industry, structural materials, electronic products and so on. At present, there have been four methods to produce Al-Ti alloys, for example, direct dissolution method,sintering method, reduction method and molten salt electrolysis method.Due to disadvantages of the synthesis methods mentioned above, it is necessary to find a new theoretical way to prepare Al-Ti alloys. As a result,there are two kinds of electrolytes used for electrodeposition of Al-Ti alloys, one is the molten salt electrolysis, and the other is the ionic liquid. The emergence of ionic liquids provide a chance to findgreen production methods for Al-Ti alloys. We have explored the different kinds of chloroaluminate ionic liquid selectrodeposition process conditions of Al-Ti alloy, and studied the electrochemical behavior of chloroaluminate ionic liquids electrodeposition of Al-Ti alloys.The major research conents and innovative results of this dissertation are listed as follows:(1)After TiF4 is added to [Bmim]Cl:2Al Cl3, the deposition potential is determined by Cyclic Voltammetry Analysis(CV). The results show that the effect of the deposition layer is not ideal, and the process is affected by the slow dissolution rate of Ti F4 in the [Bmim]Cl:2Al Cl3 solution. So it is not a proper way to deposit Al-Ti alloy in the [Bmim]Cl:2Al Cl3+0.2MTi F4 ionic liquid.(2)It is well-known that, compared with other aluminum salt ionic liquids,[Bmim]Cl:2Al Cl3+0.2MTi Cl4 is the best one. With the increase of temperature, the coating of Al-Ti alloy becomes thicker, the deposition layer becomes much more uniform and compact, Al-Ti alloys are formed at 50℃, and Al5Ti3 alloys are formed at 70℃.(3)After the mixed solution,(1≤R{M(Al Cl3):M([Bmim]Cl)}≤2),is placed more than one day,there are two peaks in the Cyclic Voltammetry Curve, Which is not found in the Cyclic Voltammetry Curve of the [Bmim]Cl:2Al Cl3+0.2MTi Cl4 solution.Considering all the relevant circumstances, we speculate that Ti Cl4 complexed with Al Cl4-, instead of Al2Cl7-,which is confirmed by Raman spectroscopy.