以TA3钛板为阳极,纯镍板为阴极,在550℃的LiCl-NaCl-KCl-TiClx体系中,研究钛离子阴极电化学行为;同时研究脉冲电解参数对阴极沉积过程的影响.结果表明:阴极上Ti3+的电化学行为是经放电变成Ti2+再进一步被还原成Ti的过程;与恒电流电解相比,脉冲电解更易得到致密沉积产物,且产物结晶度更高、氧氮含量更低;脉冲电解参数对阴极产物沉积形貌有重要影响,电解周期(tc)为10 min时,通断比(n)过大或过小均不利于阴极产物长大,且阴极电流效率低.最佳脉冲电解条件为阴极电流密度0.3 A/cm2、通电周期20 min、通断比(n)1,此时获得的阴极产物结晶度高,颗粒尺寸大且产物致密,电流效率达87.4%.
The pulsed electrodepositon behaviors of titanium on nickel cathode were investigated in LiCl-NaCl-KCl-TiClx molten salt at 550 ℃ by a molten electrolysis method using TA3 titanium plate as anode. And the effects of pulsed electrodeposition parameters on cathode products were also investigated. The results show that the electrochemical behavior of Ti3+ → Ti at cathode is a two-step diffusion-controlled process with intermediate Ti2+ and Ti+. Comparing with galvanostatic electrodeposition, the products obtained by pulsed electrodeposition have higher compactness, higher crystallinity, and lower oxygen and nitrogen contents. The parameters of pulsed electrodeposition have important influences on the deposited products. When the electrolysis cycle time is short (tc=10 min) and the ratio of current on/off (n) is higher or lower, the size of the products is smaller and the current efficiency is lower. The compact titanium products with large grains and current efficiency of 87.4% are obtained at cathodic current density of 0.3 A/cm2 when tc=20 min and n=1.