混合氧化物涂层钛基阳极的性能及其电子防腐蚀

Preparation of Titanium-Based Anodes Coated with Mixed Metal Oxides and Evaluation of Their Corrosion Resistance

辅助阳极是电子防腐蚀系统的关键部件之一,为提高其性能及寿命,利用热分解法制备了Ru-Ir-Sn-Ti混合氧化物涂层钛基阳极,用SEM,XRD,动电位极化曲线、强化电解寿命试验和热水器内胆电子防腐蚀试验考察了不同Sn含量的混合氧化物涂层钛电极的性能。结果表明:Ru-Ir-Sn-Ti混合氧化物涂层覆盖良好,呈均匀龟裂状;添加适量的Sn能提高涂层的电化学活性,含10%(摩尔分数)Sn涂层的电化学性能最优;含30%(摩尔分数)Sn涂层的强化电解寿命达58 h;混合氧化物涂层钛阳极在输入很小的电压时,能有效防止水下搪瓷碳钢在高硬度热水中的腐蚀,且能使阴极材料表面沉淀一层钙质层,增强了保护效果。

Ti anodes coated with mixed oxides RuO2-IrO2-SnO2-222 TiO2 were prepared via thermal decomposition route.The microstructure and phase composition of resultant Ti-based anodes were analyzed by scanning electron microscopy and X-ray diffraction.The corrosion resistance of the Ti-based anodes was evaluated by conducting potentiodynamic polarization curve measurement,accelerated life test,and electronic anti-corrosion test of water heater inner tank.It was found that crack-like coatings of mixed oxides well covered the Ti-based anodes.Introducing a certain content of Sn could increase the electrocatalytic activity of the coatings,and the coating anode containing 10% Sn(molar fraction,the same hereafter) possessed the best electrochemical performance.The coated Ti-based anode containing 30% Sn had an accelerated electrolysis life of 58 h.In the meantime,the coated Ti-based anodes could prevent enamel steel from corrosion in hot water with a high hardness even at a very low applied voltage,and could also form Ca-containing deposited layer on the surface of cathode,resulting in improved protection efficacy.