等离子喷涂法制备Al/TiB_2复合电极及电化学性能研究

Electrochemical Properties of Plasma Sprayed TiB_2-coated Al Composite Electrodes

采用等离子喷涂法制备出Al/TiB_2电极。运用SEM、XRD表征复合电极界面的组织形貌和物相结构,研究在相同送粉电位、喷涂距离条件下不同喷涂功率对复合电极界面电阻率及电化学性能的影响。结果表明:等离子喷涂法制备的Al/TiB_2复合电极表面涂层的物相组成为TiB_2。喷涂后的TiB_2可均匀致密地涂在Al基体表面,但并未与Al发生界面反应,而是形成机械式结合。当喷涂功率、送粉电位和喷涂距离分别为34kW、12V、10cm时试样界面电阻率最小为1.22×10^(-6)Ω·cm,较Ti/Al电极降低66%,腐蚀电流密度(1.47×10^(-4) A/cm^2)较Ti/Al电极降低81%,腐蚀电压(-0.579V)较Ti/Al电极增加35%,其耐腐蚀性能达到最好。

The Al electrode substrates were covered with TiB2 by plasma spraying to form a series of composite electrodes va- ried in spraying power, whose interface microstructures and phase structures were characterized by XRD and SEM. Under the same powder-feeding potential and spraying distance, the effect of spraying power on composite electrode＇s electrochemical performance was analyzed. The results showed that the phase compositions of the electrodes surface coatings prepared by plasma spraying were TiB2. The sprayed TiB2 can evenly and densely coat on surface of Al substrate, but no interface reaction with Al occurred and binding mode is mechanical binding. When spraying power, powder-feeding potential, and spraying distance were 34 kW, 12 V and 10 cm, respectively, the sprayed electrode had the best corrosion resistance, as its interracial resistivity 1.22 × 10^-6Ω cm was the lowest （660） lower than that of Ti/Al electrode）, and had a corrosion current density of 1.47× 10.4 A/cm^2 （81% lower than that of Ti/Al electrode） and a corrosion voltage of --0. 579 V （35% higher than that of Ti/Al electrode）.