Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (3): 551-558.doi: 10.3866/PKU.WHXB201312272

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Correlation between Galvanic Corrosion and Electronic Work Function of Al Alloy Surfaces

WANG Jian1,2,3, WANG Shao-Qing1   

  1. 1 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China;
    2 School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, P. R. China;
    3 College of Science, University of Science and Technology Liaoning, Anshan 114051, Liaoning Province, P. R. China
  • Received:2013-10-11 Revised:2013-12-27 Published:2014-02-27
  • Contact: WANG Jian E-mail:jwang12b@imr.ac.cn
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2011CB606403).

Abstract:

Al alloys contain some secondary phases to improve their properties. These secondary phases have different potentials to the Al matrix, which greatly affect the localized corrosion of Al alloys. In order to reveal the physical nature of Al alloy corrosion, we use the first-principles method based upon density functional theory to calculate the work function of the main secondary phases (Al2Cu, Al3Ti, and Al7Cu2Fe). The difficulty of electrons escaping from various crystal planes was analyzed, and the potential difference between the secondary phases and Al matrix was obtained. We find that different crystal planes exposed to the outmost layer significantly impacted on the potential difference. Different atomic types at the outmost layer play different roles in Al alloy corrosion, even for the same crystal surface. The causes of galvanic corrosion were thus revealed.

Key words: Al alloy, Second phase, Electronic work function, Galvanic corrosion, First-principles

MSC2000: 

  • O647