Stress-relaxation experiments were performed on nanotwinned Cu to characterize the twin size-dependence of the activation volume and mobile dislocation density. We find that the variation of activation volume as a function of twin lamellae thickness can be captured well by a Hall–Petch-type relation. This structure size-dependence is interpreted to arise from a transition of the rate-controllin...

The growth in investment on the effect of size in nanoscience and nanotechnology has been astounding. Of the $12.4B spent in 2006 worldwide Nanotechnology research funding [1], at least 50 % was spent on the effect of size for the development of nanomaterials and devices. The focus of nanoscience is to understand the influence of size on the material properties, while nanotechnology focuses on ...

The nanomechanical properties of BiFeO3 (BFO) thin films are subjected to nanoindentation evaluation. BFO thin films are grown on the Pt/Ti/SiO2/Si substrates by using radio frequency magnetron sputtering with various deposition temperatures. The structure was analyzed by X-ray diffraction, and the results confirmed the presence of BFO phases. Atomic force microscopy revealed that the average f...

We present detailed measurements of the temperature dependence of the Hall and longitudinal resistances on a quantum Hall device [(GaAs(7)] which has been used as a resistance standard at NIST. We find a simple power law relationship between the change in Hall resistance and the longitudinal resistance as the temperature is varied between 1.4 K and 36 K. This power law holds over seven orders o...

Abstract In order to study the effects of coarse grain size and Ni content on mechanical properties, molecular dynamics (MD) simulation nanocrystalline (NC) Ni-W alloys with bimodal structure is carried out. The NC samples are established by embedding into fine matrix. solute atoms in segregated boundary affected zone (GBAZ) through severe plastic deformation (SPD). uniaxial tensile shows that ...

The influence of the ratio between specimen thickness (t) and grain size (D) on tensile fatigue properties plain notched aluminium plate specimens has been studied. Grain sizes ranging from 66 μm to 9.74 mm have prepared used in tests. observed decrease when D is comparable, or even exceeds, t can be accounted for by adding an additional negative exponential term Hall–Petch equation. An also fo...

This research work studies the structural phase parameters and physicomechanical properties of metal-matrix composite materials based on a Ni–TiB2 system obtained by additive manufacturing (specifically, direct laser deposition). The composites were investigated at high temperatures (up to 1000 °C). feasibility fabrication nanostructure alloy with advanced was shown. introduction reinforcing Ti...