This work presents a theoretical assessment of galvanic (relative) nobility of four intermetallic particles (IMPs), Al₂Cu, Al₂CuMg, Mg₂Si 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.

The corrosion mechanism of copper and copper alloy is reviewed. A number of scientific papers have been investigated to determine the corrosion mechanism and protection techniques of copper and copper alloy corrosion. Results have shown that copper can be corroded in an acidic or an alkaline environment, and oxide formation is the corrosion initiation process. The use of corrosion inhibitors is one of several ways of controlling metal corrosion. There are inorganic (toxic) and organic (green) corrosion inhibitors invented so far. Nowadays, environmental issue is a concern of several scientists in the world. From the results of recent scientific papers, green corrosion inhibitors can be used for copper corrosion protection and they are both economical and environmentally safe. Furthermore, future researches are needed to determine more efficient, environmentally friendly corrosion inhibitors for copper and copper alloys.