Defect Energy Calculations of Nickel, Copper and Aluminium (and Their Alloys): Molecular Dynamics Approach

Abstract

AbstractStacking faults are defined as regions present in the crystal where the normal sequence of stacking is disturbed. This takes place around a localized area. These defects come under the planar defect. An important role is played by these defects in deciding the characteristic properties of face-centered cubic (FCC) metals and alloys, which are close-packed. The vacancy formation energy can be defined as the change in energy, which takes place when the breaking of the bond takes place between one atom and its ligands and the formation of new bonds of atoms with ligands. Interstitial defects are the point type defect. In this type of defect, a site that is normally not occupied is occupied by an atom of the same or different type. Nickel is a pure FCC metal, and its stacking fault energy (\(\gamma )\) ranges from 79 to 415 mJ m−2. When we remove atoms from crystalline sites, vacancy is formed. Various loading conditions were used for studying the stacking fault energy of FCC metals. Density functional theory (DFT) based on first principle calculations and the embedded atom model (EAM) were used for calculating the generalized stacking fault energy of nickel, copper and aluminium. The super cell approximation based on orbital-free DFT was used for calculating the formation energies of vacancies. Ni-based super alloys are gaining wide popularity because they have excellent strength and creep resistance. This chapter reports on the work done by researchers on evaluating various defect energies of nickel, copper and aluminium through computational techniques.KeywordsStacking fault energyVacancy formation energyInterstitial formation energyNickelAluminiumCopper