熔盐电解SiO2/TiO2制备硅钛合金的研究

采用熔盐电解法通过直接电解SiO2、TiO2混合物料来制备硅钛合金。热力学计算结果表明,在700℃下,SiO2和TiO2的理论分解电压分别为1.28V和1.37V,生成的单质硅和钛在高温下能够自发进行合金化反应,生成硅钛系列合金,且容易倾向于生成稳定合金相TiSi2合金。研究表明,以摩尔比50∶1的SiO2/TiO2混合物料为原料,在等摩尔比的CaCl2-NaCl混合熔盐中,在700℃、2.4V槽电压下,经过5h电解后,制备得到TiSi2/Si合金,微观形貌为粒径0.2~2.5μm的多孔颗粒堆积,单质硅颗粒覆盖在TiSi2合金颗粒表面。

Study on Electrochemical Preparation of Si-Ti Alloy from SiO2/TiO2 in Molten Salt

Silicon-titanium alloy was prepared by direct electrolysis of SiO2 and TiO2 mixture through molten salt electrolysis.According to thermodynamic calculation,theoretical decomposition voltage of SiO2 and TiO2 at 700°C is 1.28 V and 1.37 V respectively.Reduced metallic Si and Ti can react spontaneously to form Si-Ti alloys at high temperature,and stable TiSi2 alloy phase is produced more easily than other alloyed phases.Experimental results suggest that TiSi2/Si can be produced applying SiO2/TiO2 with molar ratio of 50:1 as raw material in equimolar CaCl2-NaCl molten salt under 2.4 V cell voltage at 700°C for 5 h.Morphology of TiSi2/Si is accumulation of porous particles with particle size of 0.2?2.5 μm,and metallic silicon covers surface of TiSi2 alloy.