铀表面脉冲偏压MSIP铝镀层的电化学腐蚀行为

Electrochemical Corrosion Behaviours of Pulsed Bias MSIP Aluminum Coating on Depleted Uranium Surface

采用脉冲偏压磁控溅射离子镀(MSIP)技术在贫铀表面制备铝镀层,利用电化学测试技术、扫描电镜(SEM)及X射线能谱(EDS)对铝镀层在50μg/g Cl-水溶液中的电化学腐蚀行为进行研究。结果表明:铝镀层的腐蚀电位-534.8 mV高于贫铀的腐蚀电位-641.2 mV,它对贫铀是一种阴极性镀层;镀铝贫铀样品的极化电阻和电化学阻抗幅值远大于贫铀,腐蚀电流远小于贫铀,铝镀层对贫铀基体具有良好的防腐蚀性能;镀铝贫铀样品的腐蚀特征为局部腐蚀,并出现镀层破裂、剥落,抗腐蚀性能变差;铝/铀界面伪扩散层具有一定的抗腐蚀能力。

Aluminum coating was prepared by magnetron sputtering ion plating （MSIP） with pulsed bias on depleted uranium surface. Its electrochemical corrosion behaviours were studied by electrochemical technology, scanning electron microscope （SEM） and X-ray energy dispersive spectroscope （EDS）. The corrosion potential of aluminum coating （-534.8 mV） is higher than that of depleted uranium （-641.2 mV）. The aluminum coating is a cathodic deposit to depleted uranium. Depleted uranium coated aluminum has much higher polarization resistance, greater magnitude of electrochemical impedance and much lower corrosion current than that of depleted uranium. The aluminum coating has a good corrosion resistance to depleted uranium. Corrosion characteristic of depleted uranium coated aluminum is a typical local corrosion. Meanwhile, the aluminum coating cracks and flakes off from depleted uranium substrate, which deteriorates its anti-corrosion property. Pseudo-diffusion layer on interface between aluminum coating and uranium substrate has some degree of anti-corrosion effect.