Abstract A review presents the results of current studies wood’s hierarchical structure using modern physical means on nano- to macro scales. Relationships between and mechanical properties at these levels are discussed. It is shown that size effects in wood strength obey Hall–Petch relationship a range around six orders magnitude structural unit characteristic sizes.

Abstract Microstructural characterisation of engineering materials is required for understanding the relationships between microstructure and mechanical properties. Conventionally grain size measured from boundary maps obtained using optical or electron microscopy. This paper implements EBSD-based linear intercept measurement spatial variation ferritic steel weld metals, making analysis flexibl...

Ultrafine-grained (UFG) nanostructured materials having grain sizes of tens and hundreds of nanometers recently have aroused interest among researchers in the materials science field. With respect to their mechanical properties, one would hope to be able to obtain the extremely strong states that can be expected in the case of strong grain refinement according to the Hall-Petch relationship (Gl...

Nanotwinned metals exhibit an unusual combination of ultrahigh strength, considerable ductility and enhanced rate sensitivity. We find that a Hall–Petch-type relationship closely fits the experiment data of activation volume as a function of twin spacing. The results suggest a transition of the rate-controlling mechanism from intra-twinto twin-boundary-mediated processes with decreasing twin la...

We introduce a modified phase field crystal (MPFC) technique that self-consistently incorporates rapid strain relaxation alongside the usual plastic deformation and multiple crystal orientations featured by the traditional phase field crystal (PFC) technique. Our MPFC formalism can be used to study a host of important phase transformation phenomena in material processing that require rapid stra...

The hallmark of materials science is the ability to tailor the structures of a given material to provide a desired response. In this work, the structures involving crystallinity and crystallographic orientation of Cu nanowires electrochemically fabricated in ion-track templates have been investigated as a function of fabrication condition. Both single crystalline and polycrystalline nanowires w...

We report on molecular-dynamics (MD) simulations of tensile loading of nano-crystalline Al modeled by an embedded-atom method (EAM) potential. Usage of two different sample preparation methods of the nano-crystalline material allows us to compare mechanical properties for different sample qualities. A Voronoi-constructed polycrystal exhibits nearly no pores and has different mechanical properti...

High temperature nanoindentation experiments are conducted to assess the activation enthalpy for deformation of nanocrystalline Ni-W alloys, for grain sizes between 3 and 80 nm. Thermal softening becomes less pronounced at finer grain sizes, and the activation enthalpy has an apparent inflection at a grain size near ~10-20 nm, in the vicinity the Hall-Petch breakdown. This inflection is related...