镁合金的应力腐蚀开裂:机理、影响因素、防护技术  

Stress Corrosion Cracking of Magnesium Alloys: Mechanism,Influencing Factors,and Prevention Technology

作　　者：宋雨来[1] 付洪德 王震 杨鹏聪 SONG Yulai;FU Hongde;WANG Zhen;YANG Pengcong(College of Materials Science and Engineering,Jilin University,Changchun 130022)

机构地区：[1]吉林大学材料科学与工程学院,长春130022

出　　处：《材料导报》2019年第5期834-840,共7页Materials Reports

基　　金：国家自然科学基金(50901035);吉林省自然科学基金(20140101051JC)~~

摘　　要：随着节能、环保要求的日益提高,环境友好型结构材料的开发及应用受到越来越高的关注。镁合金由于对环境污染小、可回收利用率高等优点而极受世人青睐,成为21世纪最具发展前景的商用轻质材料,被广泛应用于航空航天、计算机、通讯等工业领域。然而,镁合金在应用过程中暴露出许多问题。由于镁活泼的化学性质导致镁合金在服役环境下极易受到腐蚀,例如在潮湿大气、海洋、含硫气氛中都能使镁合金发生点蚀、电偶腐蚀、晶间腐蚀等,使得镁合金结构件的整体或局部受到破坏。特别是在腐蚀和外力的双重作用下,镁合金将发生应力腐蚀开裂,导致结构件发生脆断。近年来,由于镁合金应力腐蚀开裂引起的结构失效案例逐年上升,造成了巨大的经济损失。目前,关于镁合金应力腐蚀开裂的研究主要集中于机理、影响因素和防护措施等方面。国内外学者相关研究表明,镁合金应力腐蚀开裂的机理总体上主要分为阳极溶解和氢脆两种理论,其中滑移溶解和氢局部增塑分别为两种理论的主流观点。但由于镁合金材料、服役环境的多样性以及力学、电化学腐蚀行为的复杂性,现有理论机理缺乏普遍适用性,且部分缺少直接实验验证,急需进一步系统研究。镁合金抗应力腐蚀性能受到镁合金服役环境、镁合金本身的加工工艺以及镁合金中的合金元素等诸多因素的影响。因此,依据应力腐蚀机理,结合影响因素,通过合理添加合金元素开发出新的镁合金,镁合金表面激光冲击改性或表面涂层,镁合金热处理、变质处理等方法都能够很好地降低镁合金应力腐蚀开裂的敏感性。特别是添加稀土元素,例如铒、铈等,能够使得镁合金组织优化,且能形成新的稀土相,对降低其应力腐蚀开裂敏感性的效果显著。本文系统归纳了镁合金应力腐蚀开裂的研究进展,分别对镁合金应�With the increasing requirements for energy saving and environmental protection,the development and application of environmentally friendly structural materials have attracted enormous attention.Thanks to their low environmental pollution and high recycling efficiency.Magnesium alloys have become the most promising commercial lightweight materials in the 21st century,with widespread application in aerospace,computer,communications and other industrial fields.Unfortunately,many problems have also been exposed duringthe application of magnesium alloys.Suffering from the active chemical nature of magnesium,magnesium alloys are highly susceptible to corrosion in the service environment.For example,pitting corrosion,galvanic corrosion,and intergranular corrosion are likely to occur in magnesium alloys in humid atmospheres,marine atmospheres,and sulfur-containing atmospheres,leading to the whole or partial failure of structural parts of the magnesium alloy.Particularly,stress corrosion cracking of magnesium alloys may take place under the combined effects of corrosion and external force,resulting in brittle fracture of structural components.In recent years,there is a continuous increase in structural failure cases caused by stress corrosion cracking of magnesium alloys,which bring about huge economic losses.Therefore,great efforts have been put in the research work on stress corrosion cracking of magnesium alloys,focusing on their mechanism,influencing factors,and protective technologies.According to relevant studies by scholars at home and abroad,the stress corrosion cracking mechanism of magnesium alloyscan be generally explained by two major theories,namely,anodic dissolution and hydrogen embrittlement.Specifically,slipping dissolution theory and localized plasticization of hydrogen are recognized as the main viewpoints of the above mentioned two theories,respectively.However,owing to the diversity of magnesium alloy materials,service environment,and the complexity of mechanical and electrochemical corrosion behavio

关 键 词：镁合金 应力腐蚀 影响因素 防护技术 

分 类 号：TG178[金属学及工艺—金属表面处理]