Study on the trap site in Ni–Cr alloy by first principle approach

Abstract

First-principle approach for nickel chromium binary alloy with nitrogen was proposed to determine the trapping position of nitrogen in austenitic alloys. The energy of the alloy matrix with the nitrogen atoms at different positions relative to chromium atoms were calculated by density function theory. The calculated results show that the nitrogen atom diffusion along pathways through tetrahedron site consumed less energy than direct diffusion. Among the pathways through tetrahedron site, nitrogen atoms in octahedron sites without nearest neighboring chromium atom need least energy, while those with two chromium atoms need the most energy. Therefore, the trapping site for the nitrogen atom in the Cr containing alloy is the octahedron site with nearest neighboring two Cr atoms.