PSI - Issue 26

A.V. Vakhrushev et al. / Procedia Structural Integrity 26 (2020) 256–262 Vakhrushev / Structural Integrity Procedia 00 (2019) 000 – 000

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For calculations table interatomic interaction potential of atoms with a radius of interaction of 6,68 Å is used. The potential is calculated by the embedded atom. The potential is presented graphically in Fig.4. The calculations were performed using problem-oriented program complex Nano Crack, including as a computing module LAMMPS program developed by Sandia National Laboratories. To visualize the data Atom Eye program and VMD program were used. The calculations were performed with Andreev V. 3. Results of calculations Let us consider the results of numerical calculations and analysis of the interaction of aluminum and copper nanoparticles with micro cracks in the aluminum and silumin. At the first stage will examine the interaction of a single nanoparticle with a crack, and then examine the interaction of "nanoparticle system - crack." The calculations were performed at T = 400 K.

Fig. 5. Copper nanoparticle interacting with a crack in aluminum; A-A - cross-sectional of model; t=20 ps Fig.5 shows the interaction of copper nanoparticle with surface crack in aluminum at a time 20 ps. Calculations showed that the aluminum atoms, actively interacting with the atoms of copper, crawl on the nanoparticle, durable fixing it on the wall of the microcracks. Further nanoparticle is not moved. It can be seen that in this case "healing" of crack do not occur.

Fig. 6. The initial state of the model "nanoparticles - crack" Consider the interaction of nanoparticles system with a crack (Fig.6). In this case, nanosystems include 9 nanoparticles of copper and crack in the aluminum. Each aluminum nanoparticles comprise 55 atoms. The results of calculations showing the time variation of the structure of the nanosystems, are shown in Fig. 7. The figure shows that the nanoparticles are placed in the cracks begin to move into a crack to its base. Gradually a "bridge" of nanoparticles formed connecting wall cracks. Next, a "bridge" of nanoparticles contracts the walls of the crack. The result is a gradual complete overgrowth of the micro crack and a composite material of Cu and Al in place of the crack is formed.