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We describe a transmission electron microscopy investigation of the distribution of helium precipitates within the plane of an interface between Cu and V. Statistical analysis of precipitate locations reveals a weak tendency for interfacial precipitates to align along ⟨110⟩-type crystallographic directions within the Cu layer. Comparison of these findings with helium-free Cu/V interfaces suggests that the precipitates may be aggregating preferentially along atomic-size steps in the interface created by threading dislocations in the Cu layer. Our observations also suggest that some precipitates may be aggregating along intersections between interfacial misfit dislocations. IMPACT STATEMENT Theinnovationof this paper is providing the first plane-view experimental images of in-plane helium precipitate distributions at an interface between physical vapor deposited face-centered cubic (fcc) and body-centered cubic (bcc) metals. [ABSTRACT FROM PUBLISHER]

This article reviews recent basic research on two categories of metal-based nanolaminates: those composed of metal/metal constituents and those composed of metal/ceramic constituents. We focus primarily on studies that aim to understand—via experiments, modeling, or both—the biphase interface structure and its role in changing the mechanisms that govern strength and deformability at a fundamental level. We anticipate that, by providing a broad perspective on the latest advances in nanolaminates, this review will aid design of new metallic materials with unprecedented combinations of mechanical and physical properties. [ABSTRACT FROM AUTHOR]

The role of immiscible Cu/Mo interfaces on the formation of helium (He) bubbles in ion-irradiated Cu/Mo 5 nm multilayers is examined. Interfaces significantly enhance the critical He concentration above which bubbles, approximately 1 nm in diameter, are detected via through-focus imaging in a transmission electron microscope. He-to-vacancy ratio affects the formation and distribution of He bubbles. The diameter of He bubbles in Cu appears to be slightly larger than that in Mo. [ABSTRACT FROM AUTHOR]

Calcium-silicate-hydrate (C-S-H) is the main hydration product for ordinary Portland cement ( OPC) materials that exhibits a layered structure containing interfaces that controls the system response to shear deformation at the nanometer scale. In this work, we used molecular statics simulations to study the mechanical behavior of an atomistic model of C-S-H under combined loading conditions that are typical of structural applications of these materials. Combined loading is implemented by first compressing or stretching the atomistic structure to impose an external hydrostatic pressure, and then loading the system through both heterogeneous and homogeneous shear deformation. By utilizing two different shear methodologies, we were able to isolate the interface behavior from the bulk response. Our results show several qualitative similarities with that of macroscale cementitious materials including pressure sensitivity of the maximum shear strength and strength asymmetry in compression and tension. This indicates that the well-known cohesive-frictional behavior of cementitious materials is fundamental to interfaces between C-S-H grains at the nanoscale. Comparing differences in our results with nanoindentation experiments motivate future investigations of the effect of C-S-H particle size and morphology on strength scaling properties at the mesoscale. These mesoscale model interactions should include the normal-stress or pressure dependency that we observe. [ABSTRACT FROM AUTHOR]

The mechanical behavior of nanolaminates is dominated by interfaces that act as sources, barriers, and preferred sites for storage and dynamic recovery of glide dislocations. In this article, the deformation mechanisms of a variety of metal-based nanolaminates are reviewed with emphasis on unusual mechanical properties such as ultra-high flow strength without loss of plastic deformability. IMPACT STATEMENT This paper reviews the current understanding of the mechanisms and mechanics of nanolaminated composites, and discusses the future direction in predicting the mechanical behavior of laminated composites. [ABSTRACT FROM AUTHOR]

This article reviews recent basic research on two classes of twins: growth twins and deformation twins. We focus primarily on studies that aim to understand, via experiments, modeling, or both, the causes and effects of twinning at a fundamental level. We anticipate that, by providing a broad perspective on the latest advances in twinning, this review will help set the stage for designing new metallic materials with unprecedented combinations of mechanical and physical properties. [ABSTRACT FROM AUTHOR]