The Effect of Strain Localization on Galvanic Corrosion Pitting in AA7050

Author:

Nicolas Andrea1,Mello Alberto W.1,Sangid Michael D.1

Affiliation:

1. School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907.

Abstract

Corrosion is the primary failure mechanism for sea-based structures, as it plays an important role in material degradation and structural integrity. The localized corrosion behavior is affected by the micromechanics and the electrochemistry of the material; however, there are very limited studies where both mechanisms are studied jointly, let alone relative to microstructural attributes, i.e., at the mesoscale. High-resolution strain maps are created on pre-loaded AA7050 in the transverse-short orientation via digital image correlation to identify strain accumulation with respect to the microstructure. Afterward, this material is subjected to a galvanic corrosion environment. In order to investigate the driving force for localized corrosion, the microstructure, the cathodic particles, the localized strain, and the evolution of surface topology caused by corrosion pitting are spatially characterized in the region of interest. The evolution of the corroded surface is tracked every 24 h throughout the 20 d of corrosion that the material was immersed in 0.6 M NaCl solution. Specifically, three representative sized cathodic particles are monitored throughout the corrosion study, to identify their evolution of pitting before and after the particles fallout from contact with the matrix. Finally, the relationship between strain and localized galvanic corrosion is quantitatively investigated using Gaussian process modeling to identify the underlying correlations. The results show that localized strains within ±3σ of the macroscopic residual strain do not affect the corrosion rate of the material; however, extreme values beyond that threshold associated with the cracking of the particle itself seem to heavily promote the growth of localized galvanic corrosion.

Publisher

NACE International

Subject

General Materials Science,General Chemical Engineering,General Chemistry

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