報(bào)告題目：First-Principles Investigations of Corrosion Mechanisms ofLightweight Metals

報(bào)告時(shí)間：6月11日上午9:00

報(bào)告地點(diǎn)：線上騰訊會(huì)議：185724438；會(huì)議密碼：341902

報(bào)告人：齊亮 副教授

主持人：楊洋 教授

報(bào)告人簡介：

2003年于清華大學(xué)材料學(xué)院獲學(xué)士學(xué)位;

2007年于美國俄亥俄州立大學(xué)(OSU,U.S.A)獲碩士學(xué)位;

2009年于美國賓夕法尼亞大學(xué)(UPenn,U.S.A)獲材料科學(xué)與工程博士學(xué)位;

2009年至2012年期間,分別在美國賓夕法尼亞大學(xué)(UPenn,U.S.A)和麻省理工學(xué)院(MIT,U.S.A)從事博士后研究工作；

2012年至2015年期間,在加州大學(xué)伯克利分校(UC Berkeley,U.S.A)擔(dān)任科研項(xiàng)目助理；

2015年-2020年，在美國密歇根大學(xué)安娜堡分校材料工程系擔(dān)任助理教授；

2021年開始，在美國密歇根大學(xué)安娜堡分校材料工程系擔(dān)任副教授。

他的主要研究方向是利用理論和模擬計(jì)算的方法來研究材料的力學(xué)和化學(xué)性質(zhì)，包括第一性原理計(jì)算、原子模擬、多尺度建模和機(jī)器學(xué)習(xí)等。曾在2019年獲得NSF（U.S.A）職業(yè)獎(jiǎng)與2021年獲得了TMS材料加工與制造部（MPMD，U.S.A）青年領(lǐng)袖職業(yè)發(fā)展獎(jiǎng)。

報(bào)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.