超细晶镁合金的腐蚀与防护进展  

Recent Progress on Corrosion and Protection of Ultrafine-grained Magnesium Alloys

作　　者：程青鹏 黄秀玲[1] 张凡 CHENG Qing-peng;HUANG Xiu-ling;ZHANG Fan(College of Mechanical and Electronic Engineering,Nanjing Forestry University,Nanjing 210037,China;School of Materials Science and Engineering,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]南京林业大学机械电子工程学院,南京210037 [2]上海工程技术大学材料科学与工程学院,上海201620

出　　处：《表面技术》2023年第4期112-123,共12页Surface Technology

摘　　要：总结了近年来经剧烈塑性变形加工后的超细晶镁合金的腐蚀与防护研究。镁合金的初始成分可能对剧烈塑性变形加工后样品耐蚀性的变化起主导性作用。对于纯镁及含有铝或稀土等致钝性元素的合金,如AZ系和WE系镁合金,绝大多数剧烈塑性变形加工会促进生成更致密的保护膜,因而可以提升镁合金的耐蚀性。对于不含此类元素的镁合金体系,如Mg-Zn系合金,由于生成了更多的腐蚀微电偶,等通道转角挤压或高压扭转加工引起的第二相颗粒的细化和分布会加速镁合金的腐蚀,但多轴等温锻造可以提升此类合金的耐蚀性,该技术值得更多的关注。在成分相似的情况下,组织的均匀性或者第二相变化情况的影响可能较晶粒尺寸和织构演变的影响更大。对加工后的镁合金进行热处理或者表面改性是进一步提升其耐蚀性的有效手段。相对于粗晶基体,超细晶基体表面改性后的涂层的耐蚀性往往更好,值得更多的研究关注。Magnesium and its alloys are known as the green engineering material in the 21st century,but their low mechanical properties and pool corrosion resistance limit their wide engineering application and industrialization.Severe plastic deformation technology can simultaneously improve the strength and toughness of magnesium alloys through ultrafine microstructure,but the corrosion resistance of ultrafine-grained magnesium alloys varies with the changes of their own composition and microstructure,grain size,corrosion medium and preparation process.This paper summarized the recent research progresses on corrosion and protection of ultrafine-grained magnesium alloys after severe plastic deformation.In the first section,summary of the corrosion behavior of magnesium alloys processed by different severe plastic deformation techniques was introduced.Starting with the commonly used equal channel angular pressing and high-pressure torsion,the effects of chemical composition and strain induced microstructural evolution during severe plastic deformation on the corrosion behavior were clarified.It was found that the initial composition of magnesium alloys may play a dominate role in the change of corrosion resistance of samples after severe plastic deformation.For pure magnesium and magnesium alloys containing passivating elements such as aluminum or rare earth elements(AZ series,AM series,ZE series,WE series,etc.),most processing would promote the formation of a denser protective film,which could improve the corrosion resistance of magnesium alloys.However,for Mg-Zn based alloys without such elements like ZK60 and Mg-Zn-Ca alloys,due to the formation of more micro galvanic couples,the refinement and distribution of second phase particles caused by equal channel angular pressing or high-pressure torsion would accelerate the corrosion of magnesium alloys.However,multiaxial isothermal forging could improve the corrosion resistance of such alloys,which deserved more attention.In the case of similar composition,the effects of micr

关 键 词：镁合金 超细晶 剧烈塑性变形 表面改性 耐蚀性 腐蚀与防护 

分 类 号：TG174[金属学及工艺—金属表面处理]