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[en] Dislocation nucleation and interface sliding are two dominant plasticity events governing the mechanical behavior of metallic nanocomposites. Recent works have shown that both events can be closely related to atomistic interface geometries, however, how compositional factors, e.g., segregated hydrogen clusters, contribute both events are nearly unknown. Herein, we demonstrate that hydrogen clusters near misfit dislocation nodes can strongly suppress dislocation nucleation and interface sliding, while clusters at other positions will contribute somehow weaker effect on dislocation nucleation but facilitate interface sliding. These findings offer a rational atomistic mechanism for the effect of hydrogen clusters on interface facilitated plasticity.

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[en] A molecular dynamics (MD) method with an embedded atomic method (EAM) was proposed to study the atomic diffusion behavior and diffusion mechanism in the Fe–Cu bimetal casting process. The results indicated that the diffusion coefficient of the Cu atoms was larger than that of the Fe atoms at the same temperature, but the Fe atoms predominantly diffused into the Cu side in the process of diffusion bonding. Moreover, the relationship between diffusion distance and temperature was predicted by the established model, and the optimal temperature for interface diffusion bonding of Fe–Cu bimetal ranged from 1473K to 1753 K. The diffusion behavior was mainly due to vacancies, which played a key role in the formation of the Cu cluster, and the accumulation of Cu atoms decreased the system energy. Finally, FeAcknowledgmentsCu bimetal casting was prepared to validate the simulated results of the diffusion behavior and diffusion distance, and the simulated results were consistent with the experimental ones. (paper)

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[en] In the framework of this paper, the results of experimental studies on the production of thin labyrinth bimetallic films, as well as measurement of ampere characteristics from volts, are presented. In addition, the simulation of their electrically conductive properties is done. (paper)

[en] A carbon steel/Cr-cast iron bimetal produced by an alloy cored wire welding method showed a zigzag type fracture in the interface in tension tests. Results obtained from the interface were; ^σUTS=29.75(Kg/mm²) σ_ys=20.08(Kg/mm²) E=8.5 x 10⁷(psi). The evaluated value of J_IC was 0.7 Kg.f/mm. Brittle fracture were observed only in the cast structure. Wear resistance of hardfaced metal was superior to that of base metal. The wear mechanism was mostly abrasive wear,but oxidation wear and adhesive wear were also activated partly. (Author)

[en] The structural particularities of the zone of interaction between nickel aluminide surfaced,by an electron-beam technique and nickel-based alloys were investigated. A possibility was shown to slow down resorption by providing a diffusion barrier rich in chromium beneath the layer of the sufaced aluminide

[en] Misfit dislocation pattern is generally accepted to play a critical role on the interface mediated deformation mechanism such as dislocation nucleation and shear sliding in various flat interfaces, however, a specific mechanical loading may dynamically modify its distribution and character before the appearance of distinct plastic flow out of interfaces. Taking bimetal semi-coherent interfaces with high symmetrically distributed misfit dislocations as an illustration, we reveal for the first time that the dynamic evolution of misfit dislocation patterns in interface appears for some specific interface types and loading schemes, and eventually governs the preferred sites of dislocation nucleation and the shear sliding mechanism. In contrary to the nearly unchanged feature of misfit dislocations under biaxial in-plane tension, the initial patterns around nodes of misfit dislocations are found to be distorted and spread anisotropically within interface during uniaxial in-plane loading, which in turn governs the non-Schmid phenomena of dislocation nucleation. A similar dependence of shear sliding mechanism on the anisotropic feature of core spreading of misfit dislocations in interface is also observed, depending on the characteristic of misfit dislocation patterns. Further investigations suggest that the dynamic evolution of misfit dislocation patterns may differ substantially for different types of interfaces, and consequently contribute to different mechanisms of dislocation nucleation and shear sliding. These results suggest a necessity to investigate the dynamic evolution of misfit dislocation patterns to get a more realistic understanding on the interface dominated plasticity.