Effect of P impurity on mechanical properties of NiAl Σ5 grain boundary: From perspectives of stress and energy

Abstract

In this paper, we employ the first-principle total energy method to investigate the effect of P impurity on mechanical properties of NiAl grain boundary (GB). According to "energy", the segregation of P atom in NiAlΣ5 GB reduces the cleavage energy and embrittlement potential, demonstrating that P impurity embrittles NiAlΣ5 GB. The first-principle computational tensile test is conducted to determine the theoretical tensile strength of NiAlΣ5 GB. It is demonstrated that the maximum ideal tensile strength of NiAlΣ5 GB with P atom segregation is 144.5 GPa, which is lower than that of the pure NiAlΣ5 GB (164.7 GPa). It is indicated that the segregation of P weakens the theoretical strength of NiAlΣ5 GB. The analysis of atomic configuration shows that the GB fracture is caused by the interfacial bond breaking. Moreover, P is identified to weaken the interactions between Al-Al bonds and enhance Ni-Ni bonds.

Exact solution of a topological spin ring with an impurity*

“…This relation Eq. (31) indicates that Λ (u) = (−1) N Λ (−u − 1) for a finite site N, which has been proved by the direct diagonalization of t(u). [36] The above relations Eqs.…”

“…[27] The effects of impurity scattering on the surface of topological insulators have been investigated extensively. [28][29][30] A key issue is to determine the conditions for the stability of the current-carrying states at the edge of the sample, [31,32] as this is the feature that most directly impacts prospect for future applications in electronics and spintronics. [33] Therefore, it is worthwhile to investigate the effects of impurity when the impurity locates at the twisted boundary.…”