报告题目：First-Principles Investigations of Corrosion Mechanisms ofLightweight Metals

报告时间：6月11日上午9:00

报告地点：线上腾讯会议：185724438；会议密码：341902

报告人：齐亮 副教授

主持人：杨洋 教授

报告人简介：

2003年于清华大学材料学院获学士学位;

2007年于美国俄亥俄州立大学(OSU,U.S.A)获硕士学位;

2009年于美国宾夕法尼亚大学(UPenn,U.S.A)获材料科学与工程博士学位;

2009年至2012年期间,分别在美国宾夕法尼亚大学(UPenn,U.S.A)和麻省理工学院(MIT,U.S.A)从事博士后研究工作；

2012年至2015年期间,在加州大学伯克利分校(UC Berkeley,U.S.A)担任科研项目助理；

2015年-2020年，在美国密歇根大学安娜堡分校材料工程系担任助理教授；

2021年开始，在美国密歇根大学安娜堡分校材料工程系担任副教授。

他的主要研究方向是利用理论和模拟计算的方法来研究材料的力学和化学性质，包括第一性原理计算、原子模拟、多尺度建模和机器学习等。曾在2019年获得NSF（U.S.A）职业奖与2021年获得了TMS材料加工与制造部（MPMD，U.S.A）青年领袖职业发展奖。

报告摘要：

A significant challenge forapplications of lightweight metals and alloys (such as Mg and Al alloys) istheir poor corrosion resistance under service conditions. Here I present twoexamples of first-principles investigations of corrosion mechanisms of Mg andAl. The first example is to design Mg alloys with built-in corrosionresistance. Corrosion can result from the coupling of anodic dissolution of Mgand cathodic reduction of water on impurities such as Fe-rich second-phaseparticles. Experiments show that small quantities of Arsenic (As) or Germanium(Ge) can inhibit Mg corrosion, possibly slowing the hydrogen evolution reaction(HER) as the cathodic reaction on Fe surfaces. We designed thermodynamic andHER criteria and used high-throughput first-principles computations to search apool of 68 elements. Our computational results predict that As and Ge are thebest two alloying elements according to their ability to reduce the HER rate,in qualitative accord with recent experiments. The second example is tounderstand the chloride (Cl)-induced initiation mechanism of localizedcorrosion of Al alloys by investigating the interactions between Cl andhydroxylated α–Al2O3 surfaces under aqueouselectrochemical conditions. The results suggest a Cl anion can only bestabilized on these surfaces by substituting a surface hydroxyl (OH) group.This substitution is thermodynamically favorable at sites on surfaceterminations of grain boundaries (GBs) in bicrystal configurations but notfavorable at sites on single-crystal surfaces. The adsorbed Cl significantlyincreases the thermodynamic driving force for Al cation dissolution fromalumina surfaces to initiate localized corrosion.

References for the second talk:

1.Mingfei Zhang, Louis G. Hector, YangGuo, Ming Liu, Liang Qi, First-principles search for alloying elements thatincrease corrosion resistance of Mg with second-phase particles of transition metalimpurities, Computational Materials Science, 165 (2019) 154-166,

2.Sundar,A.,Chen,G.&Qi,L.Substitutional adsorptions of chloride at grainboundary sites on hydroxylated alumina surfaces initialize localized corrosion.npj Mater Degrad 5(2021)18.