Ab initio calculations of strain fields and failure patterns in silicon nitride intergranular glassy films

Anil Misra (1) , L. Ouyang (2) , Jie Chen (3) , W.Y. Ching (3)

1 CEAE - Department of Civil, Environmental and Architectural Engineering
2 Department of Mathematics and Physics
3 Department of Physics

Theoretical experiments were performed on silicon nitride intergranular glassy film (IGF) models subjected to tensile loading using an accurate ab initio method. The results were used to investigate the strain fields within IGF models. The Green–Lagrange strain fields were calculated from the displacement gradients of the IGF models under various loads. Significant deviations from the first-order Cauchy–Born rule were observed for IGF models even under small load. The strain fields were also analysed to understand atomic-scale mechanisms that lead to intergranular and intragranular failures.

Domaines: Génie mécanique [physics.class-ph]; Génie mécanique [physics.class-ph]

Anil Misra, L. Ouyang, Jie Chen, W.Y. Ching. Ab initio calculations of strain fields and failure patterns in silicon nitride intergranular glassy films. Philosophical Magazine, 2007, 87 (25), pp.3839 - 3852. ⟨hal-00555157⟩