熔盐电解制备钛锆合金及其反应过程研究

采用熔盐电解法由ZrO_2与TiO_2混合氧化物(Ti, Zr原子比为1∶ 1)一步制备出了TiZr合金, 并探讨了反应机制. 温度为900 ℃, CaCl_2熔盐中以烧结的ZrO_2与TiO_2混合氧化物为阴极,石墨棒为阳极, 3.1 V恒电压电解, 制备出了钛锆合金. 结果表明, 所得产物的组分与投料比例一致, 钛、锆为无限互溶的固溶体, 电解反应是由外向内进行的. 其合金化历程为: 部分ZrO_2先生成CaZrO_3, 然后继续脱氧还原为锆的低价氧化物直至还原为金属锆, 一旦有金属锆生成, TiO_2在金属锆上直接电解还原形成钛的低价氧化物, 直至生成金属钛后与锆形成固溶体; 其余ZrO_2, TiO_2先形成CaZr_mTi_nO_x, 然后直接脱氧还原为TiZr.

Reaction Processes and Preparation of TiZr Alloy by Electrolysis in Molten Salt

Direct preparation of TiZr alloy from ZrO_2, TiO_2 oxide mixture by electrolysis in molten salt of calcium chloride and its reaction mechanism was investigated, constant voltage (3.1 V)electrolysis, with a graphite anode and ZrO_2, TiO_2 oxide mixture as the cathode, was performed in molten salt of CaCl_2 at 900 ℃ for 0.5, 1, 3, 5, 8 and 12 h, respectively. The result showed that the atomic ratio of Ti to Zr in the prepared alloy agreed well with the pre-determined ratio, and Ti-Zr alloy produced a solid solution with complete miscibility in the entire range of composition. There were two kinds of mechanism in the process of electrolysis: part of ZrO_2 was transformed to CaZrO_3 firstly, then CaZrO_3 was reduced to Zr, once Zr metal occured, TiO_2 was reduced to Ti metal on the Zr atoms. The two kinds of metal was dissolved in each other to form TiZr solid solution; The rest of ZrO_2 and TiO_2 oxide mixture formed CaZr_mTi_nO_x firstly, then formed TiZr alloy directly.