First-Principle Calculation of Volta Potential of Intermetallic Particles in Aluminum Alloys and Practical Implications. Issue 9 (20th June 2017)

• Record Type: Journal Article
• Authors: Jin, Ying; Liu, Min; Zhang, Chuanhui; Leygraf, Christofer; Wen, Lei; Pan, Jinshan
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 9(2017)
• Page Start: C465
• Page End: C473
• Publication Date: 2017-06-20
• Subjects: aluminum alloy -- DFT calculation -- intermetallic particle -- Volta potential -- work function; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0191709jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : This work presents a theoretical assessment of galvanic (relative) nobility of four intermetallic particles (IMPs), Al2 Cu, Al2 CuMg, Mg2 Si and MgZn2, in aluminum alloys through work function calculation based on density functional theory (DFT). The concepts of work function, Volta potential and relative nobility are discussed with respect to the IMPs and aluminum matrix. The calculated Volta potentials are compared with reported experimental Volta potentials measured by scanning Kelvin probe force microscopy (SKPFM). Various crystal faces and terminal types are examined in the DFT calculation, showing that these two factors have a significant effect on the work function value. Considering the large divergence in the reported experimental data, the comparison shows a general agreement between the calculated and experimental Volta potential data for the investigated IMPs. The DFT calculations provide theoretical explanations for several experimental phenomena. The results demonstrate that DFT calculation is a valuable theoretical approach for assessment of the relative nobility of different phases in the alloys, providing complementary information to experimental data from SKFPM. Moreover, the implications of the calculated Volta potentials are discussed with respect to the corrosion potentials.