镁合金负差数效应的研究进展  

Research Progress on the Negative Difference Effect of Magnesium Alloys

作　　者：侯继禹 王保杰 许凯 许道奎[2] 孙杰[1] HOU Jiyu;WANG Baojie;XU Kai;XU Daokui;SUN Jie(School of Environmental and Chemical Engineering,Shenyang Ligong University,Shenyang 110159,China;Center for Corrosion and Protection of Materials,Institute of Metal Research,Chinese Academy of Science,Shenyang 110016,China)

机构地区：[1]沈阳理工大学环境与化学工程学院,沈阳110159 [2]中国科学院金属研究所材料腐蚀与防护中心,沈阳110016

出　　处：《材料导报》2023年第12期134-140,共7页Materials Reports

基　　金：国家自然科学基金(52071220,51871211,U21A2049);沈阳理工大学高水平成果建设项目(SYLUXM202105)。

摘　　要：随着我国工业水平的不断进步,工程应用领域对轻量化的需求愈加迫切,极大推动了镁合金的快速发展。然而,镁合金的耐蚀性较差,严重阻碍了其实际工程应用。为了有效解决镁合金耐蚀性差的问题,亟需深入研究其腐蚀机理。镁合金电化学腐蚀过程中存在典型的负差数效应(Negative difference effect,NDE),即在阳极极化下镁合金的析氢速度随电位升高而增加,与传统的电化学动力学理论相异。近年来,国内外学者对镁合金的负差数效应开展了大量研究,先后建立了局部保护膜模型、单价镁离子模型、溶解脱落模型、氢化镁促溶理论、综合理论、部分电子外电路消耗机理、析氢交换电流密度i0增大机理和电催化机理八种理论模型。基于上述模型,人们深化了对镁合金析氢过程的认识,提升了镁合金腐蚀机理的研究深度。本文综述了镁合金电化学腐蚀过程中负差数效应的基本原理及研究现状,归纳出八种负差数效应的理论模型,总结了各模型的发展历程,指出了它们各自存在的不足之处,展望了镁合金腐蚀负差数效应的研究方向。With the continuous progress in industrialization,the demand for lightweight components in engineering applications is becoming increasingly urgent,which has significantly promoted the rapid development of Mg alloys.However,the poor corrosion resistance of Mg alloys seriously hinders their practical engineering applications.To effectively solve this issue,it is essential to comprehensively study the corrosion mechanism of Mg alloys.Mg alloys exhibit a typical negative difference effect(NDE)in their electrochemical corrosion process,i.e.,the hydrogen evolution rate increases with the increase in potential under an anodic polarization process,which is different from the traditional electrochemical theory.In recent years,researchers from different countries have conducted several investigations on the NDE of Mg alloys and successively estab-lished eight theoretical models including the local protective film model,monovalent Mg ion model,dissolution and abscission model,MgH2 solu-tion promotion theory,comprehensive theory,partial external electronic circuit consumption mechanism,hydrogen evolution through an exchange current density i0 increase mechanism,and electrocatalysis mechanism.Based on the above models,a deeper understanding of the hydrogen evolution process of Mg alloys is obtained and the depth of research on the corrosion mechanism of Mg alloys is improved.This paper overviews the basic principle and research status of NDE in the electrochemical corrosion of Mg alloys,summarizes the eight theo-retical models of NDE and the development process of each model,highlights their shortcomings,and anticipates the research direction of NDE in the future.

关 键 词：镁合金 负差数效应 腐蚀 单价镁离子 理论模型 阳极极化 

分 类 号：TG178[金属学及工艺—金属表面处理]