pH对锆基底AlCrNbSiTi高熵合金涂层高温电化学行为的影响

Effect of pH on High-temperature Electrochemical Corrosion Behavior of AlCrNbSiTi High Entropy Alloy Coatings on Zr-Sn-Nb Alloy

为了提高压水堆Zr-Sn-Nb合金包壳材料的耐腐蚀性,本文使用电弧离子镀法在Zr-Sn-Nb合金基底上制备了AlCrNbSiTi高熵合金涂层,并分别在3种不同pH的水环境中进行了开路电位和动电位极化电化学的测量,通过微观表征分析了表面氧化膜的形貌、化学成分和结构,研究了pH值变化对AlCrNbSiTi高熵合金涂层高温电化学行为的影响。研究结果表明,随着pH值(7.4~8.5)的增加,涂层的开路电位下降,极化曲线的腐蚀电流密度增加,涂层表面腐蚀程度加剧。因此,AlCrNbSiTi高熵合金涂层的耐腐蚀性随着pH值(7.4~8.5)的增加而下降。

In order to improve the corrosion resistance of Zr-Sn-Nb alloy cladding material in PWR,the AlCrNbSiTi high entropy alloy coatings were prepared on Zr-Sn-Nb alloy substrates by arc ion plating,and the open-circuit potential and potentiodynamic polarization electrochemistry were measured in three different pH water environments.The morphology,chemical composition and structure of the surface oxide film were analyzed by microscopic characterization,and the influence of pH change on the high-temperature electrochemical behavior of AlCrNbSiTi high entropy alloy coating was studied.The results show that with the increase of pH(7.4-8.5),the open circuit potential of the coating decreases,the corrosion current density of polarization curve increases and the corrosion degree of the coating surface intensifies.Therefore,the corrosion resistance of AlCrNbSiTi high entropy alloy coating decreases with the increase of pH(7.4~8.5).