含Sr量对Al-Si-Zn钎料合金腐蚀性能的影响  

Effect of Sr addition on corrosion behavior of Al-Si-Zn brazing alloy

作　　者：王光宇 马瑞[2] 万明攀[2] 赵飞[2] 刘子豪 刘小刚 Wang Guangyu;Ma Rui;Wan Mingpan;Zhao Fei;Liu Zihao;Liu Xiaogang(Guizhou Aviatuon Technology Development Co.,Ltd.,Guiyang 550081,China;Guizhou University,College of Materials and Metallurgy,Guiyang 550025,China)

机构地区：[1]贵州航宇科技股份发展有限公司,贵阳550081 [2]贵州大学,材料与冶金学院,贵阳550025

出　　处：《焊接》2024年第9期7-14,共8页Welding & Joining

基　　金：贵州省科技计划(20194106,2021109)。

摘　　要：【目的】旨在探究不同Sr含量Al-Si-Zn钎料的腐蚀性能及机理。【方法】通过理论与试验结合的方法,以第一性原理为基础,探究Sr对Al-Si-Zn合金溶解电势的影响,并利用电化学测试、扫描电镜和能谱分析等方法,对不同Sr含量的Al-SiZn合金在3.5%NaCl溶液中电化学腐蚀表面形貌的变化以及开路电位和动电位极化曲线进行了研究。【结果】结果表明,当Sr在Al-Zn(100)表面的覆盖度从0.25 ML增加到0.75 ML时,表面的化学势比不添加Sr时增加了0.13~0.93 eV,而表面Al-Zn原子的溶解电极电位也向负方向移动,表明含Sr的Al-Zn(100)变得更加容易腐蚀;表面Mülliken电荷布居数表明,表面层Al原子总负电荷数随着表面Sr覆盖度增加而增加,表明功函数减小使Al更活泼,故更容易产生电化学腐蚀反应。【结论】Al-SiZn-x Sr钎料合金在3.5%NaCl溶液中电解腐蚀,钎料的腐蚀性能较未添加Sr时有所降低,而当Sr含量为0.4%时,钎料的耐蚀性最好。[Objective]The corrosion properties and mechanism of Al-Si-Zn brazing alloy with different Sr addition were studied.[Methods]By combining theory and experiment,based on the First-principles,the influence of Sr on the dissolution potential of Al-Si-Zn alloy was investigated.By means of electrochemical testing,scanning electron microscopy and energy spectrum analysis,the surface morphology and the polarization curves of open circuit potential and electromotive potential of Al-Si-Zn alloy with different Sr addition in 3.5%NaCl solution potential were studied.[Results]The results showed that when the coverage of Al-Zn(100)surface containing Sr increases from 0.25 ML to 0.75 ML,the chemical potential of Al-Zn on the surface increased by 0.13~0.93 eV compared with that without Sr,and potential of the dissolved electrode of Al-Zn atom on the surface also shifted to a negative direction,indicating that Al-Zn(100)containing Sr became more easily corroded.The Mulliken charge population on the surface indicated that the total negative charge number of Al atom in the surface layer increases with the increase of Sr coverage on the surface,it was shown that the decrease of work function makes Al more active,so it was easier to produce electrochemical corrosion reaction.[Conclusion]Al-Si-Zn-xSr brazing was electrolytically corroded in 3.5%NaCl solution.The corrosion performance of brazing metals decreased compared with that without Sr.When the addition of Sr element was 0.4%,the corrosion resistance of the brazing metal was the best.

关 键 词：Sr元素 第一性原理 电化学 腐蚀性能 

分 类 号：TG425[金属学及工艺—焊接]