Substitutional adsorptions of chloride at grain boundary sites on hydroxylated alumina surfaces initialize localized corrosion

Author:

Sundar Aditya,Chen GanlinORCID,Qi LiangORCID

Abstract

AbstractTo understand the chloride (Cl)-induced initiation mechanism of localized corrosion of Aluminum (Al) alloys, we apply density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations to investigate the interactions between Cl and hydroxylated α–Al2O3 surfaces, mainly (0001) orientation, under aqueous electrochemical conditions. Hydroxylated alumina surfaces thermodynamically stable in aqueous environments are constructed based on DFT calculations for both the single-crystal and bicrystal configurations. AIMD simulations suggest a Cl anion can only be stabilized on these surfaces by substituting a surface hydroxyl (OH) group. This substitution is thermodynamically favorable at sites on surface terminations of grain boundaries (GBs) in bicrystal configurations but not favorable at sites on single-crystal surfaces. Electronic structure analyses show that the different adsorption behaviors originate from the higher sensitivity of the Al–OH bond strength to the local coordination than its counterpart of the Al–Cl bond. The adsorbed Cl significantly increases the thermodynamic driving force for Al cation dissolution from alumina surfaces into the aqueous electrolyte, which can initiate localized corrosion.

Funder

U-M | MCubed, University of Michigan

Publisher

Springer Science and Business Media LLC

Subject

Materials Chemistry,Materials Science (miscellaneous),Chemistry (miscellaneous),Ceramics and Composites

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3