Dynamics of Consolidation and Crack Growth in Nanocluster‐Assembled Amorphous Silicon Nitride

Abstract

Consolidation and fracture dynamics in nanophase amorphous Si 3 N 4 are investigated using 10 6 -atom moleculardynamics simulations. At a pressure of 15 GPa and 2000 K, the nanophase system is almost fully consolidated within a fraction of a nanosecond. The consolidation process is welldescribed by the classical theory of sintering. Under an applied strain the consolidated system develops several cracks which propagate parallel to each other, causing failure at multiple sites. The critical strain at which the nanophase system fractures is much larger than that for crystalline Si 3 N 4 .

Atomistic damage mechanisms during hypervelocity projectile impact on AlN: A large-scale parallel molecular dynamics simulation study

“…y 0 in the case of AlN is the tetrahedral angle 109.51, with cos y 0 ¼ À1/3. This interaction potential model was successfully used to study a number of ceramic materials such as SiO 2 (Campbell et al, 1999;Vashishta et al, 1990), Si 3 N 4 (Kalia et al, 1997a, b;Tsuruta et al, 1998;Vashishta et al, 1995;Walsh et al, 2000), and SiC (Chatterjee et al, 2000;Shimojo et al, 2000;Szlufarska et al, 2005).…”

Atomistic models of hydrogenated amorphous silicon nitride from first principles

“…The force-field calculations enable one to evolve relatively big systems for longer periods of time. [15][16][17][18] On the other hand the transition from liquid to solid poses difficult requirements on the interatomic potentials since the potential has to describe the liquid and solid phase accurately at the same time. In the case of silicon, for example, the coordination changes from ϳ6 to 4 and the system additionally undergoes a metal to semiconductor transition.…”

“…[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] In general the studies consist of two consecutive parts. First one needs to obtain a structural model of the amorphous network.…”

Molecular dynamics simulations of the mechanical strength ofSi∕Si3N4interfaces

“…41 This potential provides a good description of the structural and mechanical properties and dynamical behavior ͑static structure, bulk and Young's moduli, and phonon density of states 42,43 ͒ and fracture behavior of crystalline and amorphous Si 3 N 4 . [44][45][46][47] The interface atoms, however, are treated differently than those in the bulk to describe the bonding across the Si/ Si 3 N 4 interface. An interatomic potential model for the Si/ Si 3 N 4 interface was developed using the charge transfer values computed from a self-consistent linear combination of atomic orbitals ͑LCAO͒ electronic structure calculation.…”